portaudio/src/hostapi/wasapi/pa_win_wasapi.c

/*
 * Portable Audio I/O Library WASAPI implementation
 * Copyright (c) 2006-2010 David Viens
 * Copyright (c) 2010-2019 Dmitry Kostjuchenko
 *
 * Based on the Open Source API proposed by Ross Bencina
 * Copyright (c) 1999-2019 Ross Bencina, Phil Burk
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/*
 * The text above constitutes the entire PortAudio license; however,
 * the PortAudio community also makes the following non-binding requests:
 *
 * Any person wishing to distribute modifications to the Software is
 * requested to send the modifications to the original developer so that
 * they can be incorporated into the canonical version. It is also
 * requested that these non-binding requests be included along with the
 * license above.
 */

/** @file
 @ingroup hostapi_src
 @brief WASAPI implementation of support for a host API.
 @note pa_wasapi currently requires minimum VC 2005, and the latest Vista SDK
*/

#include <windows.h>
#include <stdio.h>
#include <process.h>
#include <assert.h>

// Max device count (if defined) causes max constant device count in the device list that
// enables PaWasapi_UpdateDeviceList() API and makes it possible to update WASAPI list dynamically
#ifndef PA_WASAPI_MAX_CONST_DEVICE_COUNT
    #define PA_WASAPI_MAX_CONST_DEVICE_COUNT 0 // Force basic behavior by defining 0 if not defined by user
#endif

// Fallback from Event to the Polling method in case if latency is higher than 21.33ms, as it allows to use
// 100% of CPU inside the PA's callback.
// Note: Some USB DAC drivers are buggy when Polling method is forced in Exclusive mode, audio output becomes
//       unstable with a lot of interruptions, therefore this define is optional. The default behavior is to
//       not change the Event mode to Polling and use the mode which user provided.
//#define PA_WASAPI_FORCE_POLL_IF_LARGE_BUFFER

//! Poll mode time slots logging.
//#define PA_WASAPI_LOG_TIME_SLOTS

// WinRT
#if defined(WINAPI_FAMILY) && (WINAPI_FAMILY == WINAPI_FAMILY_APP)
    #define PA_WINRT
    #define INITGUID
#endif

// WASAPI
// using adjustments for MinGW build from @mgeier/MXE
// https://github.com/mxe/mxe/commit/f4bbc45682f021948bdaefd9fd476e2a04c4740f
#include <mmreg.h>  // must be before other Wasapi headers
#if defined(_MSC_VER) && (_MSC_VER >= 1400) || defined(__MINGW64_VERSION_MAJOR)
    #include <avrt.h>
    #define COBJMACROS
    #include <audioclient.h>
    #include <endpointvolume.h>
    #define INITGUID // Avoid additional linkage of static libs, excessive code will be optimized out by the compiler
#ifndef _MSC_VER
    #include <functiondiscoverykeys_devpkey.h>
#endif
    #include <functiondiscoverykeys.h>
    #include <mmdeviceapi.h>
    #include <devicetopology.h>    // Used to get IKsJackDescription interface
    #undef INITGUID
// Visual Studio 2010 does not support the inline keyword
#if (_MSC_VER <= 1600)
    #define inline _inline
#endif
#endif
#ifndef __MWERKS__
    #include <malloc.h>
    #include <memory.h>
#endif
#ifndef PA_WINRT
    #include <mmsystem.h>
#endif

#include "pa_util.h"
#include "pa_allocation.h"
#include "pa_hostapi.h"
#include "pa_stream.h"
#include "pa_cpuload.h"
#include "pa_process.h"
#include "pa_win_wasapi.h"
#include "pa_debugprint.h"
#include "pa_ringbuffer.h"
#include "pa_win_coinitialize.h"

#if !defined(NTDDI_VERSION) || (defined(__GNUC__) && (__GNUC__ <= 6) && !defined(__MINGW64__))

    #undef WINVER
    #undef _WIN32_WINNT
    #define WINVER       0x0600 // VISTA
    #define _WIN32_WINNT WINVER

    #ifndef WINAPI
        #define WINAPI __stdcall
    #endif

    #ifndef __unaligned
        #define __unaligned
    #endif

    #ifndef __C89_NAMELESS
        #define __C89_NAMELESS
    #endif

    #ifndef _AVRT_ //<< fix MinGW dummy compile by defining missing type: AVRT_PRIORITY
        typedef enum _AVRT_PRIORITY
        {
            AVRT_PRIORITY_LOW = -1,
            AVRT_PRIORITY_NORMAL,
            AVRT_PRIORITY_HIGH,
            AVRT_PRIORITY_CRITICAL
        } AVRT_PRIORITY, *PAVRT_PRIORITY;
    #endif

    #include <basetyps.h> // << for IID/CLSID
    #include <rpcsal.h>
    #include <sal.h>

    #ifndef __LPCGUID_DEFINED__
        #define __LPCGUID_DEFINED__
        typedef const GUID *LPCGUID;
    #endif
    typedef GUID IID;
    typedef GUID CLSID;

    #ifndef PROPERTYKEY_DEFINED
        #define PROPERTYKEY_DEFINED
        typedef struct _tagpropertykey
        {
            GUID fmtid;
            DWORD pid;
        }     PROPERTYKEY;
    #endif

    #ifdef __midl_proxy
        #define __MIDL_CONST
    #else
        #define __MIDL_CONST const
    #endif

    #ifdef WIN64
        #include <wtypes.h>
        #define FASTCALL
        #include <oleidl.h>
        #include <objidl.h>
    #else
        typedef struct _BYTE_BLOB
        {
            unsigned long clSize;
            unsigned char abData[ 1 ];
        }     BYTE_BLOB;
        typedef /* [unique] */  __RPC_unique_pointer BYTE_BLOB *UP_BYTE_BLOB;
        typedef LONGLONG REFERENCE_TIME;
        #define NONAMELESSUNION
    #endif

    #ifndef NT_SUCCESS
        typedef LONG NTSTATUS;
    #endif

    #ifndef WAVE_FORMAT_IEEE_FLOAT
        #define WAVE_FORMAT_IEEE_FLOAT 0x0003 // 32-bit floating-point
    #endif

    #ifndef __MINGW_EXTENSION
        #if defined(__GNUC__) || defined(__GNUG__)
            #define __MINGW_EXTENSION __extension__
        #else
            #define __MINGW_EXTENSION
        #endif
    #endif

    #include <sdkddkver.h>
    #include <propkeydef.h>
    #define COBJMACROS
    #define INITGUID // Avoid additional linkage of static libs, excessive code will be optimized out by the compiler
    #include <audioclient.h>
    #include <mmdeviceapi.h>
    #include <endpointvolume.h>
    #include <functiondiscoverykeys.h>
    #include <devicetopology.h>    // Used to get IKsJackDescription interface
    #undef INITGUID

#endif // NTDDI_VERSION

// Missing declarations for WinRT
#ifdef PA_WINRT

    #define DEVICE_STATE_ACTIVE 0x00000001

    typedef enum _EDataFlow
    {
        eRender                 = 0,
        eCapture                = ( eRender + 1 ) ,
        eAll                    = ( eCapture + 1 ) ,
        EDataFlow_enum_count    = ( eAll + 1 )
    }
    EDataFlow;

    typedef enum _EndpointFormFactor
    {
        RemoteNetworkDevice       = 0,
        Speakers                  = ( RemoteNetworkDevice + 1 ) ,
        LineLevel                 = ( Speakers + 1 ) ,
        Headphones                = ( LineLevel + 1 ) ,
        Microphone                = ( Headphones + 1 ) ,
        Headset                   = ( Microphone + 1 ) ,
        Handset                   = ( Headset + 1 ) ,
        UnknownDigitalPassthrough = ( Handset + 1 ) ,
        SPDIF                     = ( UnknownDigitalPassthrough + 1 ) ,
        HDMI                      = ( SPDIF + 1 ) ,
        UnknownFormFactor         = ( HDMI + 1 )
    }
    EndpointFormFactor;

#endif

#ifndef GUID_SECT
    #define GUID_SECT
#endif

#define __DEFINE_GUID(n,l,w1,w2,b1,b2,b3,b4,b5,b6,b7,b8) static const GUID n GUID_SECT = {l,w1,w2,{b1,b2,b3,b4,b5,b6,b7,b8}}
#define __DEFINE_IID(n,l,w1,w2,b1,b2,b3,b4,b5,b6,b7,b8) static const IID n GUID_SECT = {l,w1,w2,{b1,b2,b3,b4,b5,b6,b7,b8}}
#define __DEFINE_CLSID(n,l,w1,w2,b1,b2,b3,b4,b5,b6,b7,b8) static const CLSID n GUID_SECT = {l,w1,w2,{b1,b2,b3,b4,b5,b6,b7,b8}}
#define PA_DEFINE_CLSID(className, l, w1, w2, b1, b2, b3, b4, b5, b6, b7, b8) \
    __DEFINE_CLSID(pa_CLSID_##className, 0x##l, 0x##w1, 0x##w2, 0x##b1, 0x##b2, 0x##b3, 0x##b4, 0x##b5, 0x##b6, 0x##b7, 0x##b8)
#define PA_DEFINE_IID(interfaceName, l, w1, w2, b1, b2, b3, b4, b5, b6, b7, b8) \
    __DEFINE_IID(pa_IID_##interfaceName, 0x##l, 0x##w1, 0x##w2, 0x##b1, 0x##b2, 0x##b3, 0x##b4, 0x##b5, 0x##b6, 0x##b7, 0x##b8)

// "1CB9AD4C-DBFA-4c32-B178-C2F568A703B2"
PA_DEFINE_IID(IAudioClient,         1cb9ad4c, dbfa, 4c32, b1, 78, c2, f5, 68, a7, 03, b2);
// "726778CD-F60A-4EDA-82DE-E47610CD78AA"
PA_DEFINE_IID(IAudioClient2,        726778cd, f60a, 4eda, 82, de, e4, 76, 10, cd, 78, aa);
// "7ED4EE07-8E67-4CD4-8C1A-2B7A5987AD42"
PA_DEFINE_IID(IAudioClient3,        7ed4ee07, 8e67, 4cd4, 8c, 1a, 2b, 7a, 59, 87, ad, 42);
// "1BE09788-6894-4089-8586-9A2A6C265AC5"
PA_DEFINE_IID(IMMEndpoint,          1be09788, 6894, 4089, 85, 86, 9a, 2a, 6c, 26, 5a, c5);
// "A95664D2-9614-4F35-A746-DE8DB63617E6"
PA_DEFINE_IID(IMMDeviceEnumerator,  a95664d2, 9614, 4f35, a7, 46, de, 8d, b6, 36, 17, e6);
// "BCDE0395-E52F-467C-8E3D-C4579291692E"
PA_DEFINE_CLSID(IMMDeviceEnumerator,bcde0395, e52f, 467c, 8e, 3d, c4, 57, 92, 91, 69, 2e);
// "F294ACFC-3146-4483-A7BF-ADDCA7C260E2"
PA_DEFINE_IID(IAudioRenderClient,   f294acfc, 3146, 4483, a7, bf, ad, dc, a7, c2, 60, e2);
// "C8ADBD64-E71E-48a0-A4DE-185C395CD317"
PA_DEFINE_IID(IAudioCaptureClient,  c8adbd64, e71e, 48a0, a4, de, 18, 5c, 39, 5c, d3, 17);
// *2A07407E-6497-4A18-9787-32F79BD0D98F*  Or this??
PA_DEFINE_IID(IDeviceTopology,      2A07407E, 6497, 4A18, 97, 87, 32, f7, 9b, d0, d9, 8f);
// *AE2DE0E4-5BCA-4F2D-AA46-5D13F8FDB3A9*
PA_DEFINE_IID(IPart,                AE2DE0E4, 5BCA, 4F2D, aa, 46, 5d, 13, f8, fd, b3, a9);
// *4509F757-2D46-4637-8E62-CE7DB944F57B*
PA_DEFINE_IID(IKsJackDescription,   4509F757, 2D46, 4637, 8e, 62, ce, 7d, b9, 44, f5, 7b);

// Media formats:
__DEFINE_GUID(pa_KSDATAFORMAT_SUBTYPE_PCM,        0x00000001, 0x0000, 0x0010, 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71 );
__DEFINE_GUID(pa_KSDATAFORMAT_SUBTYPE_ADPCM,      0x00000002, 0x0000, 0x0010, 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71 );
__DEFINE_GUID(pa_KSDATAFORMAT_SUBTYPE_IEEE_FLOAT, 0x00000003, 0x0000, 0x0010, 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71 );

#ifdef __IAudioClient2_INTERFACE_DEFINED__
typedef enum _pa_AUDCLNT_STREAMOPTIONS {
    pa_AUDCLNT_STREAMOPTIONS_NONE          = 0x00,
    pa_AUDCLNT_STREAMOPTIONS_RAW           = 0x01,
    pa_AUDCLNT_STREAMOPTIONS_MATCH_FORMAT  = 0x02
} pa_AUDCLNT_STREAMOPTIONS;
typedef struct _pa_AudioClientProperties {
    UINT32                   cbSize;
    BOOL                     bIsOffload;
    AUDIO_STREAM_CATEGORY    eCategory;
    pa_AUDCLNT_STREAMOPTIONS Options;
} pa_AudioClientProperties;
#define PA_AUDIOCLIENTPROPERTIES_SIZE_CATEGORY (sizeof(pa_AudioClientProperties) - sizeof(pa_AUDCLNT_STREAMOPTIONS))
#define PA_AUDIOCLIENTPROPERTIES_SIZE_OPTIONS   sizeof(pa_AudioClientProperties)
#endif // __IAudioClient2_INTERFACE_DEFINED__

/* use CreateThread for CYGWIN/Windows Mobile, _beginthreadex for all others */
#if !defined(__CYGWIN__) && !defined(_WIN32_WCE)
    #define CREATE_THREAD(PROC) (HANDLE)_beginthreadex( NULL, 0, (PROC), stream, 0, &stream->dwThreadId )
    #define PA_THREAD_FUNC static unsigned WINAPI
    #define PA_THREAD_ID unsigned
#else
    #define CREATE_THREAD(PROC) CreateThread( NULL, 0, (PROC), stream, 0, &stream->dwThreadId )
    #define PA_THREAD_FUNC static DWORD WINAPI
    #define PA_THREAD_ID DWORD
#endif

// Thread function forward decl.
PA_THREAD_FUNC ProcThreadEvent(void *param);
PA_THREAD_FUNC ProcThreadPoll(void *param);

// Error codes (available since Windows 7)
#ifndef AUDCLNT_E_BUFFER_ERROR
    #define AUDCLNT_E_BUFFER_ERROR AUDCLNT_ERR(0x018)
#endif
#ifndef AUDCLNT_E_BUFFER_SIZE_NOT_ALIGNED
    #define AUDCLNT_E_BUFFER_SIZE_NOT_ALIGNED AUDCLNT_ERR(0x019)
#endif
#ifndef AUDCLNT_E_INVALID_DEVICE_PERIOD
    #define AUDCLNT_E_INVALID_DEVICE_PERIOD AUDCLNT_ERR(0x020)
#endif

// Stream flags (available since Windows 7)
#ifndef AUDCLNT_STREAMFLAGS_SRC_DEFAULT_QUALITY
    #define AUDCLNT_STREAMFLAGS_SRC_DEFAULT_QUALITY 0x08000000
#endif
#ifndef AUDCLNT_STREAMFLAGS_AUTOCONVERTPCM
    #define AUDCLNT_STREAMFLAGS_AUTOCONVERTPCM 0x80000000
#endif

#define PA_WASAPI_DEVICE_ID_LEN   256
#define PA_WASAPI_DEVICE_NAME_LEN 128
#ifdef PA_WINRT
    #define PA_WASAPI_DEVICE_MAX_COUNT 16
#endif

enum { S_INPUT = 0, S_OUTPUT = 1, S_COUNT = 2, S_FULLDUPLEX = 0 };

// Number of packets which compose single contignous buffer. With trial and error it was calculated
// that WASAPI Input sub-system uses 6 packets per whole buffer. Please provide more information
// or corrections if available.
enum { WASAPI_PACKETS_PER_INPUT_BUFFER = 6 };

#define STATIC_ARRAY_SIZE(array) (sizeof(array)/sizeof(array[0]))

#define PRINT(x) PA_DEBUG(x);

#define PA_SKELETON_SET_LAST_HOST_ERROR( errorCode, errorText ) \
    PaUtil_SetLastHostErrorInfo( paWASAPI, errorCode, errorText )

#define PA_WASAPI__IS_FULLDUPLEX(STREAM) ((STREAM)->in.clientProc && (STREAM)->out.clientProc)

#ifndef IF_FAILED_JUMP
#define IF_FAILED_JUMP(hr, label) if(FAILED(hr)) goto label;
#endif

#ifndef IF_FAILED_INTERNAL_ERROR_JUMP
#define IF_FAILED_INTERNAL_ERROR_JUMP(hr, error, label) if(FAILED(hr)) { error = paInternalError; goto label; }
#endif

#define SAFE_CLOSE(h) if ((h) != NULL) { CloseHandle((h)); (h) = NULL; }
#define SAFE_RELEASE(punk) if ((punk) != NULL) { (punk)->lpVtbl->Release((punk)); (punk) = NULL; }

// Mixer function
typedef void (*MixMonoToStereoF) (void *__to, const void *__from, UINT32 count);

// AVRT is the new "multimedia scheduling stuff"
#ifndef PA_WINRT
typedef BOOL   (WINAPI *FAvRtCreateThreadOrderingGroup)  (PHANDLE,PLARGE_INTEGER,GUID*,PLARGE_INTEGER);
typedef BOOL   (WINAPI *FAvRtDeleteThreadOrderingGroup)  (HANDLE);
typedef BOOL   (WINAPI *FAvRtWaitOnThreadOrderingGroup)  (HANDLE);
typedef HANDLE (WINAPI *FAvSetMmThreadCharacteristics)   (LPCSTR,LPDWORD);
typedef BOOL   (WINAPI *FAvRevertMmThreadCharacteristics)(HANDLE);
typedef BOOL   (WINAPI *FAvSetMmThreadPriority)          (HANDLE,AVRT_PRIORITY);
static HMODULE hDInputDLL = 0;
FAvRtCreateThreadOrderingGroup   pAvRtCreateThreadOrderingGroup = NULL;
FAvRtDeleteThreadOrderingGroup   pAvRtDeleteThreadOrderingGroup = NULL;
FAvRtWaitOnThreadOrderingGroup   pAvRtWaitOnThreadOrderingGroup = NULL;
FAvSetMmThreadCharacteristics    pAvSetMmThreadCharacteristics = NULL;
FAvRevertMmThreadCharacteristics pAvRevertMmThreadCharacteristics = NULL;
FAvSetMmThreadPriority           pAvSetMmThreadPriority = NULL;
#endif

#define _GetProc(fun, type, name)  {                                                        \
                                        fun = (type) GetProcAddress(hDInputDLL,name);       \
                                        if (fun == NULL) {                                  \
                                            PRINT(("GetProcAddr failed for %s" ,name));     \
                                            return FALSE;                                   \
                                        }                                                   \
                                    }                                                       \

// ------------------------------------------------------------------------------------------
/* prototypes for functions declared in this file */
#ifdef __cplusplus
extern "C"
{
#endif /* __cplusplus */
PaError PaWasapi_Initialize( PaUtilHostApiRepresentation **hostApi, PaHostApiIndex index );
#ifdef __cplusplus
}
#endif /* __cplusplus */
// dummy entry point for other compilers and sdks
// currently built using RC1 SDK (5600)
//#if _MSC_VER < 1400
//PaError PaWasapi_Initialize( PaUtilHostApiRepresentation **hostApi, PaHostApiIndex hostApiIndex )
//{
    //return paNoError;
//}
//#else

// ------------------------------------------------------------------------------------------
static void Terminate( struct PaUtilHostApiRepresentation *hostApi );
static PaError IsFormatSupported( struct PaUtilHostApiRepresentation *hostApi,
                                  const PaStreamParameters *inputParameters,
                                  const PaStreamParameters *outputParameters,
                                  double sampleRate );
static PaError OpenStream( struct PaUtilHostApiRepresentation *hostApi,
                           PaStream** s,
                           const PaStreamParameters *inputParameters,
                           const PaStreamParameters *outputParameters,
                           double sampleRate,
                           unsigned long framesPerBuffer,
                           PaStreamFlags streamFlags,
                           PaStreamCallback *streamCallback,
                           void *userData );
static PaError CloseStream( PaStream* stream );
static PaError StartStream( PaStream *stream );
static PaError StopStream( PaStream *stream );
static PaError AbortStream( PaStream *stream );
static PaError IsStreamStopped( PaStream *s );
static PaError IsStreamActive( PaStream *stream );
static PaTime GetStreamTime( PaStream *stream );
static double GetStreamCpuLoad( PaStream* stream );
static PaError ReadStream( PaStream* stream, void *buffer, unsigned long frames );
static PaError WriteStream( PaStream* stream, const void *buffer, unsigned long frames );
static signed long GetStreamReadAvailable( PaStream* stream );
static signed long GetStreamWriteAvailable( PaStream* stream );

// ------------------------------------------------------------------------------------------
/*
 These are fields that can be gathered from IDevice and IAudioDevice PRIOR to Initialize, and
 done in first pass i assume that neither of these will cause the Driver to "load", but again,
 who knows how they implement their stuff
 */
typedef struct PaWasapiDeviceInfo
{
    // Device
#ifndef PA_WINRT
    IMMDevice *device;
#endif

    // device Id
    WCHAR deviceId[PA_WASAPI_DEVICE_ID_LEN];

    // from GetState
    DWORD state;

    // Fields filled from IAudioDevice (_prior_ to Initialize)
    // from GetDevicePeriod(
    REFERENCE_TIME DefaultDevicePeriod;
    REFERENCE_TIME MinimumDevicePeriod;

    // Default format (setup through Control Panel by user)
    WAVEFORMATEXTENSIBLE DefaultFormat;

    // Mix format (internal format used by WASAPI audio engine)
    WAVEFORMATEXTENSIBLE MixFormat;

    // Fields filled from IMMEndpoint'sGetDataFlow
    EDataFlow flow;

    // Form-factor
    EndpointFormFactor formFactor;
}
PaWasapiDeviceInfo;

// ------------------------------------------------------------------------------------------
/* PaWasapiHostApiRepresentation - host api datastructure specific to this implementation */
typedef struct
{
    PaUtilHostApiRepresentation inheritedHostApiRep;
    PaUtilStreamInterface       callbackStreamInterface;
    PaUtilStreamInterface       blockingStreamInterface;

    PaUtilAllocationGroup      *allocations;

    /* implementation specific data goes here */

    PaWinUtilComInitializationResult comInitializationResult;

    // this is the REAL number of devices, whether they are useful to PA or not!
    UINT32 deviceCount;

    PaWasapiDeviceInfo *devInfo;

    // is TRUE when WOW64 Vista/7 Workaround is needed
    BOOL useWOW64Workaround;
}
PaWasapiHostApiRepresentation;

// ------------------------------------------------------------------------------------------
/* PaWasapiAudioClientParams - audio client parameters */
typedef struct PaWasapiAudioClientParams
{
    PaWasapiDeviceInfo *device_info;
    PaStreamParameters  stream_params;
    PaWasapiStreamInfo  wasapi_params;
    UINT32              frames_per_buffer;
    double              sample_rate;
    BOOL                blocking;
    BOOL                full_duplex;
    BOOL                wow64_workaround;
}
PaWasapiAudioClientParams;

// ------------------------------------------------------------------------------------------
/* PaWasapiStream - a stream data structure specifically for this implementation */
typedef struct PaWasapiSubStream
{
    IAudioClient        *clientParent;
#ifndef PA_WINRT
    IStream             *clientStream;
#endif
    IAudioClient        *clientProc;

    WAVEFORMATEXTENSIBLE wavex;
    UINT32               bufferSize;
    REFERENCE_TIME       deviceLatency;
    REFERENCE_TIME       period;
    double               latencySeconds;
    UINT32               framesPerHostCallback;
    AUDCLNT_SHAREMODE    shareMode;
    UINT32               streamFlags; // AUDCLNT_STREAMFLAGS_EVENTCALLBACK, ...
    UINT32               flags;
    PaWasapiAudioClientParams params; //!< parameters

    // Buffers
    UINT32               buffers;            //!< number of buffers used (from host side)
    UINT32               framesPerBuffer;    //!< number of frames per 1 buffer
    BOOL                 userBufferAndHostMatch;

    // Used for Mono >> Stereo workaround, if driver does not support it
    // (in Exclusive mode WASAPI usually refuses to operate with Mono (1-ch)
    void                *monoBuffer;     //!< pointer to buffer
    UINT32               monoBufferSize; //!< buffer size in bytes
    MixMonoToStereoF     monoMixer;         //!< pointer to mixer function

    PaUtilRingBuffer    *tailBuffer;       //!< buffer with trailing sample for blocking mode operations (only for Input)
    void                *tailBufferMemory; //!< tail buffer memory region
}
PaWasapiSubStream;

// ------------------------------------------------------------------------------------------
/* PaWasapiHostProcessor - redirects processing data */
typedef struct PaWasapiHostProcessor
{
    PaWasapiHostProcessorCallback processor;
    void *userData;
}
PaWasapiHostProcessor;

// ------------------------------------------------------------------------------------------
typedef struct PaWasapiStream
{
    /* IMPLEMENT ME: rename this */
    PaUtilStreamRepresentation streamRepresentation;
    PaUtilCpuLoadMeasurer      cpuLoadMeasurer;
    PaUtilBufferProcessor      bufferProcessor;

    // input
    PaWasapiSubStream          in;
    IAudioCaptureClient       *captureClientParent;
#ifndef PA_WINRT
    IStream                   *captureClientStream;
#endif
    IAudioCaptureClient       *captureClient;
    IAudioEndpointVolume      *inVol;

    // output
    PaWasapiSubStream          out;
    IAudioRenderClient        *renderClientParent;
#ifndef PA_WINRT
    IStream                   *renderClientStream;
#endif
    IAudioRenderClient        *renderClient;
    IAudioEndpointVolume      *outVol;

    // event handles for event-driven processing mode
    HANDLE event[S_COUNT];

    // buffer mode
    PaUtilHostBufferSizeMode bufferMode;

    // must be volatile to avoid race condition on user query while
    // thread is being started
    volatile BOOL running;

    PA_THREAD_ID dwThreadId;
    HANDLE hThread;
    HANDLE hCloseRequest;
    HANDLE hThreadStart;        //!< signalled by thread on start
    HANDLE hThreadExit;         //!< signalled by thread on exit
    HANDLE hBlockingOpStreamRD;
    HANDLE hBlockingOpStreamWR;

    // Host callback Output overrider
    PaWasapiHostProcessor hostProcessOverrideOutput;

    // Host callback Input overrider
    PaWasapiHostProcessor hostProcessOverrideInput;

    // Defines blocking/callback interface used
    BOOL bBlocking;

    // Av Task (MM thread management)
    HANDLE hAvTask;

    // Thread priority level
    PaWasapiThreadPriority nThreadPriority;

    // State handler
    PaWasapiStreamStateCallback fnStateHandler;
    void *pStateHandlerUserData;
}
PaWasapiStream;

// COM marshaling
static HRESULT MarshalSubStreamComPointers(PaWasapiSubStream *substream);
static HRESULT MarshalStreamComPointers(PaWasapiStream *stream);
static HRESULT UnmarshalSubStreamComPointers(PaWasapiSubStream *substream);
static HRESULT UnmarshalStreamComPointers(PaWasapiStream *stream);
static void ReleaseUnmarshaledSubComPointers(PaWasapiSubStream *substream);
static void ReleaseUnmarshaledComPointers(PaWasapiStream *stream);

// Local methods
static void _StreamOnStop(PaWasapiStream *stream);
static void _StreamFinish(PaWasapiStream *stream);
static void _StreamCleanup(PaWasapiStream *stream);
static HRESULT _PollGetOutputFramesAvailable(PaWasapiStream *stream, UINT32 *available);
static HRESULT _PollGetInputFramesAvailable(PaWasapiStream *stream, UINT32 *available);
static void *PaWasapi_ReallocateMemory(void *prev, size_t size);
static void PaWasapi_FreeMemory(void *ptr);
static PaSampleFormat WaveToPaFormat(const WAVEFORMATEXTENSIBLE *fmtext);

// WinRT (UWP) device list
#ifdef PA_WINRT
typedef struct PaWasapiWinrtDeviceInfo
{
    WCHAR              id[PA_WASAPI_DEVICE_ID_LEN];
    WCHAR              name[PA_WASAPI_DEVICE_NAME_LEN];
    EndpointFormFactor formFactor;
}
PaWasapiWinrtDeviceInfo;
typedef struct PaWasapiWinrtDeviceListRole
{
    WCHAR                   defaultId[PA_WASAPI_DEVICE_ID_LEN];
    PaWasapiWinrtDeviceInfo devices[PA_WASAPI_DEVICE_MAX_COUNT];
    UINT32                  deviceCount;
}
PaWasapiWinrtDeviceListRole;
typedef struct PaWasapiWinrtDeviceList
{
    PaWasapiWinrtDeviceListRole render;
    PaWasapiWinrtDeviceListRole capture;
}
PaWasapiWinrtDeviceList;
static PaWasapiWinrtDeviceList g_DeviceListInfo = { 0 };
#endif

// WinRT (UWP) device list context
#ifdef PA_WINRT
typedef struct PaWasapiWinrtDeviceListContextEntry
{
    PaWasapiWinrtDeviceInfo *info;
    EDataFlow                flow;
}
PaWasapiWinrtDeviceListContextEntry;
typedef struct PaWasapiWinrtDeviceListContext
{
    PaWasapiWinrtDeviceListContextEntry devices[PA_WASAPI_DEVICE_MAX_COUNT * 2];
}
PaWasapiWinrtDeviceListContext;
#endif

// ------------------------------------------------------------------------------------------
#define LogHostError(HRES) __LogHostError(HRES, __FUNCTION__, __FILE__, __LINE__)
static HRESULT __LogHostError(HRESULT res, const char *func, const char *file, int line)
{
    const char *text = NULL;
    switch (res)
    {
    case S_OK: return res;
    case E_POINTER                              :text ="E_POINTER"; break;
    case E_INVALIDARG                           :text ="E_INVALIDARG"; break;

    case AUDCLNT_E_NOT_INITIALIZED              :text ="AUDCLNT_E_NOT_INITIALIZED"; break;
    case AUDCLNT_E_ALREADY_INITIALIZED          :text ="AUDCLNT_E_ALREADY_INITIALIZED"; break;
    case AUDCLNT_E_WRONG_ENDPOINT_TYPE          :text ="AUDCLNT_E_WRONG_ENDPOINT_TYPE"; break;
    case AUDCLNT_E_DEVICE_INVALIDATED           :text ="AUDCLNT_E_DEVICE_INVALIDATED"; break;
    case AUDCLNT_E_NOT_STOPPED                  :text ="AUDCLNT_E_NOT_STOPPED"; break;
    case AUDCLNT_E_BUFFER_TOO_LARGE             :text ="AUDCLNT_E_BUFFER_TOO_LARGE"; break;
    case AUDCLNT_E_OUT_OF_ORDER                 :text ="AUDCLNT_E_OUT_OF_ORDER"; break;
    case AUDCLNT_E_UNSUPPORTED_FORMAT           :text ="AUDCLNT_E_UNSUPPORTED_FORMAT"; break;
    case AUDCLNT_E_INVALID_SIZE                 :text ="AUDCLNT_E_INVALID_SIZE"; break;
    case AUDCLNT_E_DEVICE_IN_USE                :text ="AUDCLNT_E_DEVICE_IN_USE"; break;
    case AUDCLNT_E_BUFFER_OPERATION_PENDING     :text ="AUDCLNT_E_BUFFER_OPERATION_PENDING"; break;
    case AUDCLNT_E_THREAD_NOT_REGISTERED        :text ="AUDCLNT_E_THREAD_NOT_REGISTERED"; break;
    case AUDCLNT_E_EXCLUSIVE_MODE_NOT_ALLOWED   :text ="AUDCLNT_E_EXCLUSIVE_MODE_NOT_ALLOWED"; break;
    case AUDCLNT_E_ENDPOINT_CREATE_FAILED       :text ="AUDCLNT_E_ENDPOINT_CREATE_FAILED"; break;
    case AUDCLNT_E_SERVICE_NOT_RUNNING          :text ="AUDCLNT_E_SERVICE_NOT_RUNNING"; break;
    case AUDCLNT_E_EVENTHANDLE_NOT_EXPECTED     :text ="AUDCLNT_E_EVENTHANDLE_NOT_EXPECTED"; break;
    case AUDCLNT_E_EXCLUSIVE_MODE_ONLY          :text ="AUDCLNT_E_EXCLUSIVE_MODE_ONLY"; break;
    case AUDCLNT_E_BUFDURATION_PERIOD_NOT_EQUAL :text ="AUDCLNT_E_BUFDURATION_PERIOD_NOT_EQUAL"; break;
    case AUDCLNT_E_EVENTHANDLE_NOT_SET          :text ="AUDCLNT_E_EVENTHANDLE_NOT_SET"; break;
    case AUDCLNT_E_INCORRECT_BUFFER_SIZE        :text ="AUDCLNT_E_INCORRECT_BUFFER_SIZE"; break;
    case AUDCLNT_E_BUFFER_SIZE_ERROR            :text ="AUDCLNT_E_BUFFER_SIZE_ERROR"; break;
    case AUDCLNT_E_CPUUSAGE_EXCEEDED            :text ="AUDCLNT_E_CPUUSAGE_EXCEEDED"; break;
    case AUDCLNT_E_BUFFER_ERROR                 :text ="AUDCLNT_E_BUFFER_ERROR"; break;
    case AUDCLNT_E_BUFFER_SIZE_NOT_ALIGNED      :text ="AUDCLNT_E_BUFFER_SIZE_NOT_ALIGNED"; break;
    case AUDCLNT_E_INVALID_DEVICE_PERIOD        :text ="AUDCLNT_E_INVALID_DEVICE_PERIOD"; break;

#ifdef AUDCLNT_E_INVALID_STREAM_FLAG
    case AUDCLNT_E_INVALID_STREAM_FLAG          :text ="AUDCLNT_E_INVALID_STREAM_FLAG"; break;
#endif
#ifdef AUDCLNT_E_ENDPOINT_OFFLOAD_NOT_CAPABLE
    case AUDCLNT_E_ENDPOINT_OFFLOAD_NOT_CAPABLE :text ="AUDCLNT_E_ENDPOINT_OFFLOAD_NOT_CAPABLE"; break;
#endif
#ifdef AUDCLNT_E_OUT_OF_OFFLOAD_RESOURCES
    case AUDCLNT_E_OUT_OF_OFFLOAD_RESOURCES     :text ="AUDCLNT_E_OUT_OF_OFFLOAD_RESOURCES"; break;
#endif
#ifdef AUDCLNT_E_OFFLOAD_MODE_ONLY
    case AUDCLNT_E_OFFLOAD_MODE_ONLY            :text ="AUDCLNT_E_OFFLOAD_MODE_ONLY"; break;
#endif
#ifdef AUDCLNT_E_NONOFFLOAD_MODE_ONLY
    case AUDCLNT_E_NONOFFLOAD_MODE_ONLY         :text ="AUDCLNT_E_NONOFFLOAD_MODE_ONLY"; break;
#endif
#ifdef AUDCLNT_E_RESOURCES_INVALIDATED
    case AUDCLNT_E_RESOURCES_INVALIDATED        :text ="AUDCLNT_E_RESOURCES_INVALIDATED"; break;
#endif
#ifdef AUDCLNT_E_RAW_MODE_UNSUPPORTED
    case AUDCLNT_E_RAW_MODE_UNSUPPORTED         :text ="AUDCLNT_E_RAW_MODE_UNSUPPORTED"; break;
#endif
#ifdef AUDCLNT_E_ENGINE_PERIODICITY_LOCKED
    case AUDCLNT_E_ENGINE_PERIODICITY_LOCKED    :text ="AUDCLNT_E_ENGINE_PERIODICITY_LOCKED"; break;
#endif
#ifdef AUDCLNT_E_ENGINE_FORMAT_LOCKED
    case AUDCLNT_E_ENGINE_FORMAT_LOCKED         :text ="AUDCLNT_E_ENGINE_FORMAT_LOCKED"; break;
#endif

    case AUDCLNT_S_BUFFER_EMPTY                 :text ="AUDCLNT_S_BUFFER_EMPTY"; break;
    case AUDCLNT_S_THREAD_ALREADY_REGISTERED    :text ="AUDCLNT_S_THREAD_ALREADY_REGISTERED"; break;
    case AUDCLNT_S_POSITION_STALLED             :text ="AUDCLNT_S_POSITION_STALLED"; break;

    // other windows common errors:
    case CO_E_NOTINITIALIZED                    :text ="CO_E_NOTINITIALIZED: you must call CoInitialize() before Pa_OpenStream()"; break;

    default:
        text = "UNKNOWN ERROR";
    }
    PRINT(("WASAPI ERROR HRESULT: 0x%X : %s\n [FUNCTION: %s FILE: %s {LINE: %d}]\n", res, text, func, file, line));
#ifndef PA_ENABLE_DEBUG_OUTPUT
    (void)func; (void)file; (void)line;
#endif
    PA_SKELETON_SET_LAST_HOST_ERROR(res, text);
    return res;
}

// ------------------------------------------------------------------------------------------
#define LogPaError(PAERR) __LogPaError(PAERR, __FUNCTION__, __FILE__, __LINE__)
static PaError __LogPaError(PaError err, const char *func, const char *file, int line)
{
    if (err == paNoError)
        return err;

    PRINT(("WASAPI ERROR PAERROR: %i : %s\n [FUNCTION: %s FILE: %s {LINE: %d}]\n", err, Pa_GetErrorText(err), func, file, line));
#ifndef PA_ENABLE_DEBUG_OUTPUT
    (void)func; (void)file; (void)line;
#endif
    return err;
}

// ------------------------------------------------------------------------------------------
/*! \class ThreadSleepScheduler
           Allows to emulate thread sleep of less than 1 millisecond under Windows. Scheduler
           calculates number of times the thread must run until next sleep of 1 millisecond.
           It does not make thread sleeping for real number of microseconds but rather controls
           how many of imaginary microseconds the thread task can allow thread to sleep.
*/
typedef struct ThreadIdleScheduler
{
    UINT32 m_idle_microseconds; //!< number of microseconds to sleep
    UINT32 m_next_sleep;        //!< next sleep round
    UINT32 m_i;                    //!< current round iterator position
    UINT32 m_resolution;        //!< resolution in number of milliseconds
}
ThreadIdleScheduler;

//! Setup scheduler.
static void ThreadIdleScheduler_Setup(ThreadIdleScheduler *sched, UINT32 resolution, UINT32 microseconds)
{
    assert(microseconds != 0);
    assert(resolution != 0);
    assert((resolution * 1000) >= microseconds);

    memset(sched, 0, sizeof(*sched));

    sched->m_idle_microseconds = microseconds;
    sched->m_resolution        = resolution;
    sched->m_next_sleep        = (resolution * 1000) / microseconds;
}

//! Iterate and check if can sleep.
static inline UINT32 ThreadIdleScheduler_NextSleep(ThreadIdleScheduler *sched)
{
    // advance and check if thread can sleep
    if (++sched->m_i == sched->m_next_sleep)
    {
        sched->m_i = 0;
        return sched->m_resolution;
    }
    return 0;
}

// ------------------------------------------------------------------------------------------
typedef struct _SystemTimer
{
    INT32 granularity;

} SystemTimer;
static LARGE_INTEGER g_SystemTimerFrequency;
static BOOL          g_SystemTimerUseQpc = FALSE;

//! Set granularity of the system timer.
static BOOL SystemTimer_SetGranularity(SystemTimer *timer, UINT32 granularity)
{
#ifndef PA_WINRT
    TIMECAPS caps;

    timer->granularity = granularity;

    if (timeGetDevCaps(&caps, sizeof(caps)) == MMSYSERR_NOERROR)
    {
        if (timer->granularity < (INT32)caps.wPeriodMin)
            timer->granularity = (INT32)caps.wPeriodMin;
    }

    if (timeBeginPeriod(timer->granularity) != TIMERR_NOERROR)
    {
        PRINT(("SetSystemTimer: timeBeginPeriod(1) failed!\n"));

        timer->granularity = 10;
        return FALSE;
    }
#else
    (void)granularity;

    // UWP does not support increase of the timer precision change and thus calling WaitForSingleObject with anything
    // below 10 milliseconds will cause underruns for input and output stream.
    timer->granularity = 10;
#endif

    return TRUE;
}

//! Restore granularity of the system timer.
static void SystemTimer_RestoreGranularity(SystemTimer *timer)
{
#ifndef PA_WINRT
    if (timer->granularity != 0)
    {
        if (timeEndPeriod(timer->granularity) != TIMERR_NOERROR)
        {
            PRINT(("RestoreSystemTimer: timeEndPeriod(1) failed!\n"));
        }
    }
#else
    (void)timer;
#endif
}

//! Initialize high-resolution time getter.
static void SystemTimer_InitializeTimeGetter()
{
    g_SystemTimerUseQpc = QueryPerformanceFrequency(&g_SystemTimerFrequency);
}

//! Get high-resolution time in milliseconds (using QPC by default).
static inline LONGLONG SystemTimer_GetTime(SystemTimer *timer)
{
    (void)timer;

    // QPC: https://docs.microsoft.com/en-us/windows/win32/sysinfo/acquiring-high-resolution-time-stamps
    if (g_SystemTimerUseQpc)
    {
        LARGE_INTEGER now;
        QueryPerformanceCounter(&now);
        return (now.QuadPart * 1000LL) / g_SystemTimerFrequency.QuadPart;
    }
    else
    {
    #ifdef PA_WINRT
        return GetTickCount64();
    #else
        return timeGetTime();
    #endif
    }
}

// ------------------------------------------------------------------------------------------
/*static double nano100ToMillis(REFERENCE_TIME ref)
{
    //  1 nano = 0.000000001 seconds
    //100 nano = 0.0000001   seconds
    //100 nano = 0.0001   milliseconds
    return ((double)ref) * 0.0001;
}*/

// ------------------------------------------------------------------------------------------
static double nano100ToSeconds(REFERENCE_TIME ref)
{
    //  1 nano = 0.000000001 seconds
    //100 nano = 0.0000001   seconds
    //100 nano = 0.0001   milliseconds
    return ((double)ref) * 0.0000001;
}

// ------------------------------------------------------------------------------------------
/*static REFERENCE_TIME MillisTonano100(double ref)
{
    //  1 nano = 0.000000001 seconds
    //100 nano = 0.0000001   seconds
    //100 nano = 0.0001   milliseconds
    return (REFERENCE_TIME)(ref / 0.0001);
}*/

// ------------------------------------------------------------------------------------------
static REFERENCE_TIME SecondsTonano100(double ref)
{
    //  1 nano = 0.000000001 seconds
    //100 nano = 0.0000001   seconds
    //100 nano = 0.0001   milliseconds
    return (REFERENCE_TIME)(ref / 0.0000001);
}

// ------------------------------------------------------------------------------------------
// Makes Hns period from frames and sample rate
static REFERENCE_TIME MakeHnsPeriod(UINT32 nFrames, DWORD nSamplesPerSec)
{
    return (REFERENCE_TIME)((10000.0 * 1000 / nSamplesPerSec * nFrames) + 0.5);
}

// ------------------------------------------------------------------------------------------
// Converts PaSampleFormat to bits per sample value
// Note: paCustomFormat stands for 8.24 format (24-bits inside 32-bit containers)
static WORD PaSampleFormatToBitsPerSample(PaSampleFormat format_id)
{
    switch (format_id & ~paNonInterleaved)
    {
        case paFloat32:
        case paInt32: return 32;
        case paCustomFormat:
        case paInt24: return 24;
        case paInt16: return 16;
        case paInt8:
        case paUInt8: return 8;
    }
    return 0;
}

// ------------------------------------------------------------------------------------------
// Convert PaSampleFormat to valid sample format for I/O, e.g. if paCustomFormat is specified
// it will be converted to paInt32, other formats pass through
// Note: paCustomFormat stands for 8.24 format (24-bits inside 32-bit containers)
static PaSampleFormat GetSampleFormatForIO(PaSampleFormat format_id)
{
    return ((format_id & ~paNonInterleaved) == paCustomFormat ?
        (paInt32 | (format_id & paNonInterleaved ? paNonInterleaved : 0)) : format_id);
}

// ------------------------------------------------------------------------------------------
// Converts Hns period into number of frames
static UINT32 MakeFramesFromHns(REFERENCE_TIME hnsPeriod, UINT32 nSamplesPerSec)
{
    UINT32 nFrames = (UINT32)(    // frames =
        1.0 * hnsPeriod *        // hns *
        nSamplesPerSec /        // (frames / s) /
        1000 /                    // (ms / s) /
        10000                    // (hns / s) /
        + 0.5                    // rounding
    );
    return nFrames;
}

// Aligning function type
typedef UINT32 (*ALIGN_FUNC) (UINT32 v, UINT32 align);

// ------------------------------------------------------------------------------------------
// Aligns 'v' backwards
static UINT32 ALIGN_BWD(UINT32 v, UINT32 align)
{
    return ((v - (align ? v % align : 0)));
}

// ------------------------------------------------------------------------------------------
// Aligns 'v' forward
static UINT32 ALIGN_FWD(UINT32 v, UINT32 align)
{
    UINT32 remainder = (align ? (v % align) : 0);
    if (remainder == 0)
        return v;
    return v + (align - remainder);
}

// ------------------------------------------------------------------------------------------
// Get next value power of 2
static UINT32 ALIGN_NEXT_POW2(UINT32 v)
{
    UINT32 v2 = 1;
    while (v > (v2 <<= 1)) { }
    v = v2;
    return v;
}

// ------------------------------------------------------------------------------------------
// Aligns WASAPI buffer to 128 byte packet boundary. HD Audio will fail to play if buffer
// is misaligned. This problem was solved in Windows 7 were AUDCLNT_E_BUFFER_SIZE_NOT_ALIGNED
// is thrown although we must align for Vista anyway.
static UINT32 AlignFramesPerBuffer(UINT32 nFrames, UINT32 nBlockAlign, ALIGN_FUNC pAlignFunc)
{
#define HDA_PACKET_SIZE (128)

    UINT32 bytes = nFrames * nBlockAlign;
    UINT32 packets;

    // align to a HD Audio packet size
    bytes = pAlignFunc(bytes, HDA_PACKET_SIZE);

    // atlest 1 frame must be available
    if (bytes < HDA_PACKET_SIZE)
        bytes = HDA_PACKET_SIZE;

    packets = bytes / HDA_PACKET_SIZE;
    bytes   = packets * HDA_PACKET_SIZE;
    nFrames = bytes / nBlockAlign;

    // WASAPI frames are always aligned to at least 8
    nFrames = ALIGN_FWD(nFrames, 8);

    return nFrames;

#undef HDA_PACKET_SIZE
}

// ------------------------------------------------------------------------------------------
static UINT32 GetFramesSleepTime(REFERENCE_TIME nFrames, REFERENCE_TIME nSamplesPerSec)
{
    REFERENCE_TIME nDuration;
    if (nSamplesPerSec == 0)
        return 0;

#define REFTIMES_PER_SEC       10000000LL
#define REFTIMES_PER_MILLISEC  10000LL

    // Calculate the actual duration of the allocated buffer.
    nDuration = (REFTIMES_PER_SEC * nFrames) / nSamplesPerSec;
    return (UINT32)(nDuration / REFTIMES_PER_MILLISEC);

#undef REFTIMES_PER_SEC
#undef REFTIMES_PER_MILLISEC
}

// ------------------------------------------------------------------------------------------
static UINT32 GetFramesSleepTimeMicroseconds(REFERENCE_TIME nFrames, REFERENCE_TIME nSamplesPerSec)
{
    REFERENCE_TIME nDuration;
    if (nSamplesPerSec == 0)
        return 0;

#define REFTIMES_PER_SEC       10000000LL
#define REFTIMES_PER_MILLISEC  10000LL

    // Calculate the actual duration of the allocated buffer.
    nDuration = (REFTIMES_PER_SEC * nFrames) / nSamplesPerSec;
    return (UINT32)(nDuration / 10);

#undef REFTIMES_PER_SEC
#undef REFTIMES_PER_MILLISEC
}

// ------------------------------------------------------------------------------------------
#ifndef PA_WINRT
static BOOL SetupAVRT()
{
    hDInputDLL = LoadLibraryA("avrt.dll");
    if (hDInputDLL == NULL)
        return FALSE;

    _GetProc(pAvRtCreateThreadOrderingGroup,  FAvRtCreateThreadOrderingGroup,  "AvRtCreateThreadOrderingGroup");
    _GetProc(pAvRtDeleteThreadOrderingGroup,  FAvRtDeleteThreadOrderingGroup,  "AvRtDeleteThreadOrderingGroup");
    _GetProc(pAvRtWaitOnThreadOrderingGroup,  FAvRtWaitOnThreadOrderingGroup,  "AvRtWaitOnThreadOrderingGroup");
    _GetProc(pAvSetMmThreadCharacteristics,   FAvSetMmThreadCharacteristics,   "AvSetMmThreadCharacteristicsA");
    _GetProc(pAvRevertMmThreadCharacteristics,FAvRevertMmThreadCharacteristics,"AvRevertMmThreadCharacteristics");
    _GetProc(pAvSetMmThreadPriority,          FAvSetMmThreadPriority,          "AvSetMmThreadPriority");

    return pAvRtCreateThreadOrderingGroup &&
        pAvRtDeleteThreadOrderingGroup &&
        pAvRtWaitOnThreadOrderingGroup &&
        pAvSetMmThreadCharacteristics &&
        pAvRevertMmThreadCharacteristics &&
        pAvSetMmThreadPriority;
}
#endif

// ------------------------------------------------------------------------------------------
static void CloseAVRT()
{
#ifndef PA_WINRT
    if (hDInputDLL != NULL)
        FreeLibrary(hDInputDLL);
    hDInputDLL = NULL;
#endif
}

// ------------------------------------------------------------------------------------------
static BOOL IsWow64()
{
#ifndef PA_WINRT

    // http://msdn.microsoft.com/en-us/library/ms684139(VS.85).aspx

    typedef BOOL (WINAPI *LPFN_ISWOW64PROCESS) (HANDLE, PBOOL);
    LPFN_ISWOW64PROCESS fnIsWow64Process;

    BOOL bIsWow64 = FALSE;

    // IsWow64Process is not available on all supported versions of Windows.
    // Use GetModuleHandle to get a handle to the DLL that contains the function
    // and GetProcAddress to get a pointer to the function if available.

    fnIsWow64Process = (LPFN_ISWOW64PROCESS) GetProcAddress(
        GetModuleHandleA("kernel32"), "IsWow64Process");

    if (fnIsWow64Process == NULL)
        return FALSE;

    if (!fnIsWow64Process(GetCurrentProcess(), &bIsWow64))
        return FALSE;

    return bIsWow64;

#else

    return FALSE;

#endif
}

// ------------------------------------------------------------------------------------------
typedef enum EWindowsVersion
{
    WINDOWS_UNKNOWN = 0,
    WINDOWS_VISTA_SERVER2008,
    WINDOWS_7_SERVER2008R2,
    WINDOWS_8_SERVER2012,
    WINDOWS_8_1_SERVER2012R2,
    WINDOWS_10_SERVER2016,
    WINDOWS_FUTURE
}
EWindowsVersion;
// Alternative way for checking Windows version (allows to check version on Windows 8.1 and up)
#ifndef PA_WINRT
static BOOL IsWindowsVersionOrGreater(WORD wMajorVersion, WORD wMinorVersion, WORD wServicePackMajor)
{
    typedef ULONGLONG (NTAPI *LPFN_VERSETCONDITIONMASK)(ULONGLONG ConditionMask, DWORD TypeMask, BYTE Condition);
    typedef BOOL (WINAPI *LPFN_VERIFYVERSIONINFO)(LPOSVERSIONINFOEXA lpVersionInformation, DWORD dwTypeMask, DWORDLONG dwlConditionMask);

    LPFN_VERSETCONDITIONMASK fnVerSetConditionMask;
    LPFN_VERIFYVERSIONINFO fnVerifyVersionInfo;
    OSVERSIONINFOEXA osvi = { sizeof(osvi), 0, 0, 0, 0, {0}, 0, 0 };
    DWORDLONG dwlConditionMask;

    fnVerSetConditionMask = (LPFN_VERSETCONDITIONMASK)GetProcAddress(GetModuleHandleA("kernel32"), "VerSetConditionMask");
    fnVerifyVersionInfo = (LPFN_VERIFYVERSIONINFO)GetProcAddress(GetModuleHandleA("kernel32"), "VerifyVersionInfoA");

    if ((fnVerSetConditionMask == NULL) || (fnVerifyVersionInfo == NULL))
        return FALSE;

    dwlConditionMask = fnVerSetConditionMask(
        fnVerSetConditionMask(
            fnVerSetConditionMask(
                0, VER_MAJORVERSION,     VER_GREATER_EQUAL),
                   VER_MINORVERSION,     VER_GREATER_EQUAL),
                   VER_SERVICEPACKMAJOR, VER_GREATER_EQUAL);

    osvi.dwMajorVersion    = wMajorVersion;
    osvi.dwMinorVersion    = wMinorVersion;
    osvi.wServicePackMajor = wServicePackMajor;

    return (fnVerifyVersionInfo(&osvi, VER_MAJORVERSION | VER_MINORVERSION | VER_SERVICEPACKMAJOR, dwlConditionMask) != FALSE);
}
#endif
// Get Windows version
static EWindowsVersion GetWindowsVersion()
{
#ifndef PA_WINRT
    static EWindowsVersion version = WINDOWS_UNKNOWN;

    if (version == WINDOWS_UNKNOWN)
    {
        DWORD dwMajorVersion = 0xFFFFFFFFU, dwMinorVersion = 0, dwBuild = 0;

        // RTL_OSVERSIONINFOW equals OSVERSIONINFOW but it is missing inb MinGW winnt.h header,
        // thus use OSVERSIONINFOW for greater portability
        typedef NTSTATUS (WINAPI *LPFN_RTLGETVERSION)(POSVERSIONINFOW lpVersionInformation);
        LPFN_RTLGETVERSION fnRtlGetVersion;

        #define NTSTATUS_SUCCESS ((NTSTATUS)0x00000000L)

        // RtlGetVersion must be able to provide true Windows version (Windows 10 may be reported as Windows 8
        // by GetVersion API)
        if ((fnRtlGetVersion = (LPFN_RTLGETVERSION)GetProcAddress(GetModuleHandleA("ntdll"), "RtlGetVersion")) != NULL)
        {
            OSVERSIONINFOW ver = { sizeof(OSVERSIONINFOW), 0, 0, 0, 0, {0} };

            PRINT(("WASAPI: getting Windows version with RtlGetVersion()\n"));

            if (fnRtlGetVersion(&ver) == NTSTATUS_SUCCESS)
            {
                dwMajorVersion = ver.dwMajorVersion;
                dwMinorVersion = ver.dwMinorVersion;
                dwBuild        = ver.dwBuildNumber;
            }
        }

        #undef NTSTATUS_SUCCESS

        // fallback to GetVersion if RtlGetVersion is missing
        if (dwMajorVersion == 0xFFFFFFFFU)
        {
            typedef DWORD (WINAPI *LPFN_GETVERSION)(VOID);
            LPFN_GETVERSION fnGetVersion;

            if ((fnGetVersion = (LPFN_GETVERSION)GetProcAddress(GetModuleHandleA("kernel32"), "GetVersion")) != NULL)
            {
                DWORD dwVersion;

                PRINT(("WASAPI: getting Windows version with GetVersion()\n"));

                dwVersion = fnGetVersion();

                dwMajorVersion = (DWORD)(LOBYTE(LOWORD(dwVersion)));
                dwMinorVersion = (DWORD)(HIBYTE(LOWORD(dwVersion)));

                if (dwVersion < 0x80000000)
                    dwBuild = (DWORD)(HIWORD(dwVersion));
            }
        }

        if (dwMajorVersion != 0xFFFFFFFFU)
        {
            switch (dwMajorVersion)
            {
            case 0:
            case 1:
            case 2:
            case 3:
            case 4:
            case 5:
                break; // skip lower
            case 6:
                switch (dwMinorVersion)
                {
                case 0:  version = WINDOWS_VISTA_SERVER2008; break;
                case 1:  version = WINDOWS_7_SERVER2008R2;   break;
                case 2:  version = WINDOWS_8_SERVER2012;     break;
                case 3:  version = WINDOWS_8_1_SERVER2012R2; break;
                default: version = WINDOWS_FUTURE;           break;
                }
                break;
            case 10:
                switch (dwMinorVersion)
                {
                case 0:  version = WINDOWS_10_SERVER2016;    break;
                default: version = WINDOWS_FUTURE;           break;
                }
                break;
            default:
                version = WINDOWS_FUTURE;
                break;
            }
        }
        // fallback to VerifyVersionInfo if RtlGetVersion and GetVersion are missing
        else
        {
            PRINT(("WASAPI: getting Windows version with VerifyVersionInfo()\n"));

            if (IsWindowsVersionOrGreater(10, 0, 0))
                version = WINDOWS_10_SERVER2016;
            else
            if (IsWindowsVersionOrGreater(6, 3, 0))
                version = WINDOWS_8_1_SERVER2012R2;
            else
            if (IsWindowsVersionOrGreater(6, 2, 0))
                version = WINDOWS_8_SERVER2012;
            else
            if (IsWindowsVersionOrGreater(6, 1, 0))
                version = WINDOWS_7_SERVER2008R2;
            else
            if (IsWindowsVersionOrGreater(6, 0, 0))
                version = WINDOWS_VISTA_SERVER2008;
            else
                version = WINDOWS_FUTURE;
        }

        PRINT(("WASAPI: Windows version = %d\n", version));
    }

    return version;
#else
    #if (_WIN32_WINNT >= _WIN32_WINNT_WIN10)
        return WINDOWS_10_SERVER2016;
    #else
        return WINDOWS_8_SERVER2012;
    #endif
#endif
}

// ------------------------------------------------------------------------------------------
static BOOL UseWOW64Workaround()
{
    // note: WOW64 bug is common to Windows Vista x64, thus we fall back to safe Poll-driven
    //       method. Windows 7 x64 seems has WOW64 bug fixed.

    return (IsWow64() && (GetWindowsVersion() == WINDOWS_VISTA_SERVER2008));
}

// ------------------------------------------------------------------------------------------
static UINT32 GetAudioClientVersion()
{
    if (GetWindowsVersion() >= WINDOWS_10_SERVER2016)
        return 3;
    else
    if (GetWindowsVersion() >= WINDOWS_8_SERVER2012)
        return 2;

    return 1;
}

// ------------------------------------------------------------------------------------------
static const IID *GetAudioClientIID()
{
    static const IID *cli_iid = NULL;
    if (cli_iid == NULL)
    {
        UINT32 cli_version = GetAudioClientVersion();
        switch (cli_version)
        {
        case 3:  cli_iid = &pa_IID_IAudioClient3; break;
        case 2:  cli_iid = &pa_IID_IAudioClient2; break;
        default: cli_iid = &pa_IID_IAudioClient;  break;
        }

        PRINT(("WASAPI: IAudioClient version = %d\n", cli_version));
    }

    return cli_iid;
}

// ------------------------------------------------------------------------------------------
typedef enum EMixDirection
{
    MIX_DIR__1TO2,   //!< mix one channel to L and R
    MIX_DIR__2TO1,   //!< mix L and R channels to one channel
    MIX_DIR__2TO1_L  //!< mix only L channel (of total 2 channels) to one channel
}
EMixDirection;

// ------------------------------------------------------------------------------------------
#define _WASAPI_MONO_TO_STEREO_MIXER_1_TO_2(TYPE)\
    TYPE * __restrict to = (TYPE *)__to;\
    const TYPE * __restrict from = (const TYPE *)__from;\
    const TYPE * __restrict end = from + count;\
    while (from != end)\
    {\
        to[0] = to[1] = *from ++;\
        to += 2;\
    }

// ------------------------------------------------------------------------------------------
#define _WASAPI_MONO_TO_STEREO_MIXER_2_TO_1_FLT32(TYPE)\
    TYPE * __restrict to = (TYPE *)__to;\
    const TYPE * __restrict from = (const TYPE *)__from;\
    const TYPE * __restrict end = to + count;\
    while (to != end)\
    {\
        *to ++ = (TYPE)((float)(from[0] + from[1]) * 0.5f);\
        from += 2;\
    }

// ------------------------------------------------------------------------------------------
#define _WASAPI_MONO_TO_STEREO_MIXER_2_TO_1_INT32(TYPE)\
    TYPE * __restrict to = (TYPE *)__to;\
    const TYPE * __restrict from = (const TYPE *)__from;\
    const TYPE * __restrict end = to + count;\
    while (to != end)\
    {\
        *to ++ = (TYPE)(((INT32)from[0] + (INT32)from[1]) >> 1);\
        from += 2;\
    }

// ------------------------------------------------------------------------------------------
#define _WASAPI_MONO_TO_STEREO_MIXER_2_TO_1_INT64(TYPE)\
    TYPE * __restrict to = (TYPE *)__to;\
    const TYPE * __restrict from = (const TYPE *)__from;\
    const TYPE * __restrict end = to + count;\
    while (to != end)\
    {\
        *to ++ = (TYPE)(((INT64)from[0] + (INT64)from[1]) >> 1);\
        from += 2;\
    }

// ------------------------------------------------------------------------------------------
#define _WASAPI_MONO_TO_STEREO_MIXER_2_TO_1_L(TYPE)\
    TYPE * __restrict to = (TYPE *)__to;\
    const TYPE * __restrict from = (const TYPE *)__from;\
    const TYPE * __restrict end = to + count;\
    while (to != end)\
    {\
        *to ++ = from[0];\
        from += 2;\
    }

// ------------------------------------------------------------------------------------------
static void _MixMonoToStereo_1TO2_8(void *__to, const void *__from, UINT32 count) { _WASAPI_MONO_TO_STEREO_MIXER_1_TO_2(BYTE); }
static void _MixMonoToStereo_1TO2_16(void *__to, const void *__from, UINT32 count) { _WASAPI_MONO_TO_STEREO_MIXER_1_TO_2(short); }
static void _MixMonoToStereo_1TO2_8_24(void *__to, const void *__from, UINT32 count) { _WASAPI_MONO_TO_STEREO_MIXER_1_TO_2(int); /* !!! int24 data is contained in 32-bit containers*/ }
static void _MixMonoToStereo_1TO2_32(void *__to, const void *__from, UINT32 count) { _WASAPI_MONO_TO_STEREO_MIXER_1_TO_2(int); }
static void _MixMonoToStereo_1TO2_32f(void *__to, const void *__from, UINT32 count) { _WASAPI_MONO_TO_STEREO_MIXER_1_TO_2(float); }
static void _MixMonoToStereo_1TO2_24(void *__to, const void *__from, UINT32 count)
{
    const UCHAR * __restrict from = (const UCHAR *)__from;
    UCHAR * __restrict to = (UCHAR *)__to;
    const UCHAR * __restrict end = to + (count * (2 * 3));

    while (to != end)
    {
        to[0] = to[3] = from[0];
        to[1] = to[4] = from[1];
        to[2] = to[5] = from[2];

        from += 3;
        to += (2 * 3);
    }
}

// ------------------------------------------------------------------------------------------
static void _MixMonoToStereo_2TO1_8(void *__to, const void *__from, UINT32 count) { _WASAPI_MONO_TO_STEREO_MIXER_2_TO_1_INT32(BYTE); }
static void _MixMonoToStereo_2TO1_16(void *__to, const void *__from, UINT32 count) { _WASAPI_MONO_TO_STEREO_MIXER_2_TO_1_INT32(short); }
static void _MixMonoToStereo_2TO1_8_24(void *__to, const void *__from, UINT32 count) { _WASAPI_MONO_TO_STEREO_MIXER_2_TO_1_INT32(int); /* !!! int24 data is contained in 32-bit containers*/ }
static void _MixMonoToStereo_2TO1_32(void *__to, const void *__from, UINT32 count) { _WASAPI_MONO_TO_STEREO_MIXER_2_TO_1_INT64(int); }
static void _MixMonoToStereo_2TO1_32f(void *__to, const void *__from, UINT32 count) { _WASAPI_MONO_TO_STEREO_MIXER_2_TO_1_FLT32(float); }
static void _MixMonoToStereo_2TO1_24(void *__to, const void *__from, UINT32 count)
{
    const UCHAR * __restrict from = (const UCHAR *)__from;
    UCHAR * __restrict to = (UCHAR *)__to;
    const UCHAR * __restrict end = to + (count * 3);
    PaInt32 tempL, tempR, tempM;

    while (to != end)
    {
        tempL = (((PaInt32)from[0]) << 8);
        tempL = tempL | (((PaInt32)from[1]) << 16);
        tempL = tempL | (((PaInt32)from[2]) << 24);

        tempR = (((PaInt32)from[3]) << 8);
        tempR = tempR | (((PaInt32)from[4]) << 16);
        tempR = tempR | (((PaInt32)from[5]) << 24);

        tempM = (tempL + tempR) >> 1;

        to[0] = (UCHAR)(tempM >> 8);
        to[1] = (UCHAR)(tempM >> 16);
        to[2] = (UCHAR)(tempM >> 24);

        from += (2 * 3);
        to += 3;
    }
}

// ------------------------------------------------------------------------------------------
static void _MixMonoToStereo_2TO1_8_L(void *__to, const void *__from, UINT32 count) { _WASAPI_MONO_TO_STEREO_MIXER_2_TO_1_L(BYTE); }
static void _MixMonoToStereo_2TO1_16_L(void *__to, const void *__from, UINT32 count) { _WASAPI_MONO_TO_STEREO_MIXER_2_TO_1_L(short); }
static void _MixMonoToStereo_2TO1_8_24_L(void *__to, const void *__from, UINT32 count) { _WASAPI_MONO_TO_STEREO_MIXER_2_TO_1_L(int); /* !!! int24 data is contained in 32-bit containers*/ }
static void _MixMonoToStereo_2TO1_32_L(void *__to, const void *__from, UINT32 count) { _WASAPI_MONO_TO_STEREO_MIXER_2_TO_1_L(int); }
static void _MixMonoToStereo_2TO1_32f_L(void *__to, const void *__from, UINT32 count) { _WASAPI_MONO_TO_STEREO_MIXER_2_TO_1_L(float); }
static void _MixMonoToStereo_2TO1_24_L(void *__to, const void *__from, UINT32 count)
{
    const UCHAR * __restrict from = (const UCHAR *)__from;
    UCHAR * __restrict to = (UCHAR *)__to;
    const UCHAR * __restrict end = to + (count * 3);

    while (to != end)
    {
        to[0] = from[0];
        to[1] = from[1];
        to[2] = from[2];

        from += (2 * 3);
        to += 3;
    }
}

// ------------------------------------------------------------------------------------------
static MixMonoToStereoF GetMonoToStereoMixer(const WAVEFORMATEXTENSIBLE *fmtext, EMixDirection dir)
{
    PaSampleFormat format = WaveToPaFormat(fmtext);

    switch (dir)
    {
    case MIX_DIR__1TO2:
        switch (format & ~paNonInterleaved)
        {
        case paUInt8:   return _MixMonoToStereo_1TO2_8;
        case paInt16:   return _MixMonoToStereo_1TO2_16;
        case paInt24:   return (fmtext->Format.wBitsPerSample == 32 ? _MixMonoToStereo_1TO2_8_24 : _MixMonoToStereo_1TO2_24);
        case paInt32:   return _MixMonoToStereo_1TO2_32;
        case paFloat32: return _MixMonoToStereo_1TO2_32f;
        }
        break;

    case MIX_DIR__2TO1:
        switch (format & ~paNonInterleaved)
        {
        case paUInt8:   return _MixMonoToStereo_2TO1_8;
        case paInt16:   return _MixMonoToStereo_2TO1_16;
        case paInt24:   return (fmtext->Format.wBitsPerSample == 32 ? _MixMonoToStereo_2TO1_8_24 : _MixMonoToStereo_2TO1_24);
        case paInt32:   return _MixMonoToStereo_2TO1_32;
        case paFloat32: return _MixMonoToStereo_2TO1_32f;
        }
        break;

    case MIX_DIR__2TO1_L:
        switch (format & ~paNonInterleaved)
        {
        case paUInt8:   return _MixMonoToStereo_2TO1_8_L;
        case paInt16:   return _MixMonoToStereo_2TO1_16_L;
        case paInt24:   return (fmtext->Format.wBitsPerSample == 32 ? _MixMonoToStereo_2TO1_8_24_L : _MixMonoToStereo_2TO1_24_L);
        case paInt32:   return _MixMonoToStereo_2TO1_32_L;
        case paFloat32: return _MixMonoToStereo_2TO1_32f_L;
        }
        break;
    }

    return NULL;
}

// ------------------------------------------------------------------------------------------
#ifdef PA_WINRT
typedef struct PaActivateAudioInterfaceCompletionHandler
{
    IActivateAudioInterfaceCompletionHandler parent;
    volatile LONG refs;
    volatile LONG done;
    struct
    {
        const IID *iid;
        void **obj;
    }
    in;
    struct
    {
        HRESULT hr;
    }
    out;
}
PaActivateAudioInterfaceCompletionHandler;

static HRESULT (STDMETHODCALLTYPE PaActivateAudioInterfaceCompletionHandler_QueryInterface)(
    IActivateAudioInterfaceCompletionHandler *This, REFIID riid, void **ppvObject)
{
    PaActivateAudioInterfaceCompletionHandler *handler = (PaActivateAudioInterfaceCompletionHandler *)This;

    // From MSDN:
    // "The IAgileObject interface is a marker interface that indicates that an object
    //  is free threaded and can be called from any apartment."
    if (IsEqualIID(riid, &IID_IUnknown) ||
        IsEqualIID(riid, &IID_IAgileObject))
    {
        IActivateAudioInterfaceCompletionHandler_AddRef((IActivateAudioInterfaceCompletionHandler *)handler);
        (*ppvObject) = handler;
        return S_OK;
    }

    return E_NOINTERFACE;
}

static ULONG (STDMETHODCALLTYPE PaActivateAudioInterfaceCompletionHandler_AddRef)(
    IActivateAudioInterfaceCompletionHandler *This)
{
    PaActivateAudioInterfaceCompletionHandler *handler = (PaActivateAudioInterfaceCompletionHandler *)This;

    return InterlockedIncrement(&handler->refs);
}

static ULONG (STDMETHODCALLTYPE PaActivateAudioInterfaceCompletionHandler_Release)(
    IActivateAudioInterfaceCompletionHandler *This)
{
    PaActivateAudioInterfaceCompletionHandler *handler = (PaActivateAudioInterfaceCompletionHandler *)This;
    ULONG refs;

    if ((refs = InterlockedDecrement(&handler->refs)) == 0)
    {
        PaUtil_FreeMemory(handler->parent.lpVtbl);
        PaUtil_FreeMemory(handler);
    }

    return refs;
}

static HRESULT (STDMETHODCALLTYPE PaActivateAudioInterfaceCompletionHandler_ActivateCompleted)(
    IActivateAudioInterfaceCompletionHandler *This, IActivateAudioInterfaceAsyncOperation *activateOperation)
{
    PaActivateAudioInterfaceCompletionHandler *handler = (PaActivateAudioInterfaceCompletionHandler *)This;

    HRESULT hr = S_OK;
    HRESULT hrActivateResult = S_OK;
    IUnknown *punkAudioInterface = NULL;

    // Check for a successful activation result
    hr = IActivateAudioInterfaceAsyncOperation_GetActivateResult(activateOperation, &hrActivateResult, &punkAudioInterface);
    if (SUCCEEDED(hr) && SUCCEEDED(hrActivateResult))
    {
        // Get pointer to the requested audio interface
        IUnknown_QueryInterface(punkAudioInterface, handler->in.iid, handler->in.obj);
        if ((*handler->in.obj) == NULL)
            hrActivateResult = E_FAIL;
    }
    SAFE_RELEASE(punkAudioInterface);

    if (SUCCEEDED(hr))
        handler->out.hr = hrActivateResult;
    else
        handler->out.hr = hr;

    // Got client object, stop busy waiting in ActivateAudioInterface
    InterlockedExchange(&handler->done, TRUE);

    return hr;
}

static IActivateAudioInterfaceCompletionHandler *CreateActivateAudioInterfaceCompletionHandler(const IID *iid, void **client)
{
    PaActivateAudioInterfaceCompletionHandler *handler = PaUtil_AllocateMemory(sizeof(PaActivateAudioInterfaceCompletionHandler));

    memset(handler, 0, sizeof(*handler));

    handler->parent.lpVtbl = PaUtil_AllocateMemory(sizeof(*handler->parent.lpVtbl));
    handler->parent.lpVtbl->QueryInterface    = &PaActivateAudioInterfaceCompletionHandler_QueryInterface;
    handler->parent.lpVtbl->AddRef            = &PaActivateAudioInterfaceCompletionHandler_AddRef;
    handler->parent.lpVtbl->Release           = &PaActivateAudioInterfaceCompletionHandler_Release;
    handler->parent.lpVtbl->ActivateCompleted = &PaActivateAudioInterfaceCompletionHandler_ActivateCompleted;
    handler->refs   = 1;
    handler->in.iid = iid;
    handler->in.obj = client;

    return (IActivateAudioInterfaceCompletionHandler *)handler;
}
#endif

// ------------------------------------------------------------------------------------------
#ifdef PA_WINRT
static HRESULT WinRT_GetDefaultDeviceId(WCHAR *deviceId, UINT32 deviceIdMax, EDataFlow flow)
{
    switch (flow)
    {
    case eRender:
        if (g_DeviceListInfo.render.defaultId[0] != 0)
            wcsncpy_s(deviceId, deviceIdMax, g_DeviceListInfo.render.defaultId, wcslen(g_DeviceListInfo.render.defaultId));
        else
            StringFromGUID2(&DEVINTERFACE_AUDIO_RENDER, deviceId, deviceIdMax);
        break;
    case eCapture:
        if (g_DeviceListInfo.capture.defaultId[0] != 0)
            wcsncpy_s(deviceId, deviceIdMax, g_DeviceListInfo.capture.defaultId, wcslen(g_DeviceListInfo.capture.defaultId));
        else
            StringFromGUID2(&DEVINTERFACE_AUDIO_CAPTURE, deviceId, deviceIdMax);
        break;
    default:
        return S_FALSE;
    }

    return S_OK;
}
#endif

// ------------------------------------------------------------------------------------------
#ifdef PA_WINRT
static HRESULT WinRT_ActivateAudioInterface(const WCHAR *deviceId, const IID *iid, void **client)
{
    PaError result = paNoError;
    HRESULT hr = S_OK;
    IActivateAudioInterfaceAsyncOperation *asyncOp = NULL;
    IActivateAudioInterfaceCompletionHandler *handler = CreateActivateAudioInterfaceCompletionHandler(iid, client);
    PaActivateAudioInterfaceCompletionHandler *handlerImpl = (PaActivateAudioInterfaceCompletionHandler *)handler;
    UINT32 sleepToggle = 0;

    // Async operation will call back to IActivateAudioInterfaceCompletionHandler::ActivateCompleted
    // which must be an agile interface implementation
    hr = ActivateAudioInterfaceAsync(deviceId, iid, NULL, handler, &asyncOp);
    IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);

    // Wait in busy loop for async operation to complete
    // Use Interlocked API here to ensure that ->done variable is read every time through the loop
    while (SUCCEEDED(hr) && !InterlockedOr(&handlerImpl->done, 0))
    {
        Sleep(sleepToggle ^= 1);
    }

    hr = handlerImpl->out.hr;

error:

    SAFE_RELEASE(asyncOp);
    SAFE_RELEASE(handler);

    return hr;
}
#endif

// ------------------------------------------------------------------------------------------
static HRESULT ActivateAudioInterface(const PaWasapiDeviceInfo *deviceInfo, const PaWasapiStreamInfo *streamInfo,
    IAudioClient **client)
{
    HRESULT hr;

#ifndef PA_WINRT
    if (FAILED(hr = IMMDevice_Activate(deviceInfo->device, GetAudioClientIID(), CLSCTX_ALL, NULL, (void **)client)))
        return hr;
#else
    if (FAILED(hr = WinRT_ActivateAudioInterface(deviceInfo->deviceId, GetAudioClientIID(), (void **)client)))
        return hr;
#endif

    // Set audio client options (applicable only to IAudioClient2+): options may affect the audio format
    // support by IAudioClient implementation and therefore we should set them before GetClosestFormat()
    // in order to correctly match the requested format
#ifdef __IAudioClient2_INTERFACE_DEFINED__
    if ((streamInfo != NULL) && (GetAudioClientVersion() >= 2))
    {
        pa_AudioClientProperties audioProps = { 0 };
        audioProps.cbSize     = sizeof(pa_AudioClientProperties);
        audioProps.bIsOffload = FALSE;
        audioProps.eCategory  = (AUDIO_STREAM_CATEGORY)streamInfo->streamCategory;
        switch (streamInfo->streamOption)
        {
        case eStreamOptionRaw:
            if (GetWindowsVersion() >= WINDOWS_8_1_SERVER2012R2)
                audioProps.Options = pa_AUDCLNT_STREAMOPTIONS_RAW;
            break;
        case eStreamOptionMatchFormat:
            if (GetWindowsVersion() >= WINDOWS_10_SERVER2016)
                audioProps.Options = pa_AUDCLNT_STREAMOPTIONS_MATCH_FORMAT;
            break;
        }

        if (FAILED(hr = IAudioClient2_SetClientProperties((IAudioClient2 *)(*client), (AudioClientProperties *)&audioProps)))
        {
            PRINT(("WASAPI: IAudioClient2_SetClientProperties(IsOffload = %d, Category = %d, Options = %d) failed\n", audioProps.bIsOffload, audioProps.eCategory, audioProps.Options));
            LogHostError(hr);
        }
        else
        {
            PRINT(("WASAPI: IAudioClient2 set properties: IsOffload = %d, Category = %d, Options = %d\n", audioProps.bIsOffload, audioProps.eCategory, audioProps.Options));
        }
    }
#endif

    return S_OK;
}

// ------------------------------------------------------------------------------------------
#ifdef PA_WINRT
// Windows 10 SDK 10.0.15063.0 has SignalObjectAndWait defined again (unlike in 10.0.14393.0 and lower)
#if !defined(WDK_NTDDI_VERSION) || (WDK_NTDDI_VERSION < NTDDI_WIN10_RS2)
static DWORD SignalObjectAndWait(HANDLE hObjectToSignal, HANDLE hObjectToWaitOn, DWORD dwMilliseconds, BOOL bAlertable)
{
    SetEvent(hObjectToSignal);
    return WaitForSingleObjectEx(hObjectToWaitOn, dwMilliseconds, bAlertable);
}
#endif
#endif

// ------------------------------------------------------------------------------------------
static void NotifyStateChanged(PaWasapiStream *stream, UINT32 flags, HRESULT hr)
{
    if (stream->fnStateHandler == NULL)
        return;

    if (FAILED(hr))
        flags |= paWasapiStreamStateError;

    stream->fnStateHandler((PaStream *)stream, flags, hr, stream->pStateHandlerUserData);
}

// ------------------------------------------------------------------------------------------
static void FillBaseDeviceInfo(PaDeviceInfo *deviceInfo, PaHostApiIndex hostApiIndex)
{
    deviceInfo->structVersion = 2;
    deviceInfo->hostApi       = hostApiIndex;
}

// ------------------------------------------------------------------------------------------
static PaError FillInactiveDeviceInfo(PaWasapiHostApiRepresentation *paWasapi, PaDeviceInfo *deviceInfo)
{
    if (deviceInfo->name == NULL)
        deviceInfo->name = (char *)PaUtil_GroupAllocateMemory(paWasapi->allocations, 1);

    if (deviceInfo->name != NULL)
    {
        ((char *)deviceInfo->name)[0] = 0;
    }
    else
        return paInsufficientMemory;

    return paNoError;
}

// ------------------------------------------------------------------------------------------
static PaError FillDeviceInfo(PaWasapiHostApiRepresentation *paWasapi, void *pEndPoints, INT32 index, const WCHAR *defaultRenderId,
    const WCHAR *defaultCaptureId, PaDeviceInfo *deviceInfo, PaWasapiDeviceInfo *wasapiDeviceInfo
#ifdef PA_WINRT
    , PaWasapiWinrtDeviceListContext *deviceListContext
#endif
)
{
    HRESULT hr;
    PaError result;
    PaUtilHostApiRepresentation *hostApi = (PaUtilHostApiRepresentation *)paWasapi;
#ifdef PA_WINRT
    PaWasapiWinrtDeviceListContextEntry *listEntry = &deviceListContext->devices[index];
    (void)pEndPoints;
    (void)defaultRenderId;
    (void)defaultCaptureId;
#endif

#ifndef PA_WINRT
    hr = IMMDeviceCollection_Item((IMMDeviceCollection *)pEndPoints, index, &wasapiDeviceInfo->device);
    IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);

    // Get device Id
    {
        WCHAR *deviceId;

        hr = IMMDevice_GetId(wasapiDeviceInfo->device, &deviceId);
        IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);

        wcsncpy(wasapiDeviceInfo->deviceId, deviceId, PA_WASAPI_DEVICE_ID_LEN - 1);
        CoTaskMemFree(deviceId);
    }

    // Get state of the device
    hr = IMMDevice_GetState(wasapiDeviceInfo->device, &wasapiDeviceInfo->state);
    IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);
    if (wasapiDeviceInfo->state != DEVICE_STATE_ACTIVE)
    {
        PRINT(("WASAPI device: %d is not currently available (state:%d)\n", index, wasapiDeviceInfo->state));
    }

    // Get basic device info
    {
        IPropertyStore *pProperty;
        IMMEndpoint *endpoint;
        PROPVARIANT value;

        hr = IMMDevice_OpenPropertyStore(wasapiDeviceInfo->device, STGM_READ, &pProperty);
        IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);

        // "Friendly" Name
        {
            PropVariantInit(&value);

            hr = IPropertyStore_GetValue(pProperty, &PKEY_Device_FriendlyName, &value);
            IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);

            if ((deviceInfo->name = (char *)PaUtil_GroupAllocateMemory(paWasapi->allocations, PA_WASAPI_DEVICE_NAME_LEN)) == NULL)
            {
                result = paInsufficientMemory;
                PropVariantClear(&value);
                goto error;
            }
            if (value.pwszVal)
                WideCharToMultiByte(CP_UTF8, 0, value.pwszVal, (INT32)wcslen(value.pwszVal), (char *)deviceInfo->name, PA_WASAPI_DEVICE_NAME_LEN - 1, 0, 0);
            else
                _snprintf((char *)deviceInfo->name, PA_WASAPI_DEVICE_NAME_LEN - 1, "baddev%d", index);

            PropVariantClear(&value);

            PA_DEBUG(("WASAPI:%d| name[%s]\n", index, deviceInfo->name));
        }

        // Default format
        {
            PropVariantInit(&value);

            hr = IPropertyStore_GetValue(pProperty, &PKEY_AudioEngine_DeviceFormat, &value);
            IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);

            memcpy(&wasapiDeviceInfo->DefaultFormat, value.blob.pBlobData, min(sizeof(wasapiDeviceInfo->DefaultFormat), value.blob.cbSize));

            PropVariantClear(&value);
        }

        // Form factor
        {
            PropVariantInit(&value);

            hr = IPropertyStore_GetValue(pProperty, &PKEY_AudioEndpoint_FormFactor, &value);
            IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);

        // set
        #if defined(DUMMYUNIONNAME) && defined(NONAMELESSUNION)
            // avoid breaking strict-aliasing rules in such line: (EndpointFormFactor)(*((UINT *)(((WORD *)&value.wReserved3)+1)));
            UINT v;
            memcpy(&v, (((WORD *)&value.wReserved3) + 1), sizeof(v));
            wasapiDeviceInfo->formFactor = (EndpointFormFactor)v;
        #else
            wasapiDeviceInfo->formFactor = (EndpointFormFactor)value.uintVal;
        #endif

            PA_DEBUG(("WASAPI:%d| form-factor[%d]\n", index, wasapiDeviceInfo->formFactor));

            PropVariantClear(&value);
        }

        // Data flow (Renderer or Capture)
        hr = IMMDevice_QueryInterface(wasapiDeviceInfo->device, &pa_IID_IMMEndpoint, (void **)&endpoint);
        if (SUCCEEDED(hr))
        {
            hr = IMMEndpoint_GetDataFlow(endpoint, &wasapiDeviceInfo->flow);
            SAFE_RELEASE(endpoint);
        }

        SAFE_RELEASE(pProperty);
    }
#else
    // Set device Id
    wcsncpy(wasapiDeviceInfo->deviceId, listEntry->info->id, PA_WASAPI_DEVICE_ID_LEN - 1);

    // Set device name
    if ((deviceInfo->name = (char *)PaUtil_GroupAllocateMemory(paWasapi->allocations, PA_WASAPI_DEVICE_NAME_LEN)) == NULL)
    {
        result = paInsufficientMemory;
        goto error;
    }
    ((char *)deviceInfo->name)[0] = 0;
    if (listEntry->info->name[0] != 0)
        WideCharToMultiByte(CP_UTF8, 0, listEntry->info->name, (INT32)wcslen(listEntry->info->name), (char *)deviceInfo->name, PA_WASAPI_DEVICE_NAME_LEN - 1, 0, 0);
    if (deviceInfo->name[0] == 0) // fallback if WideCharToMultiByte is failed, or listEntry is nameless
        _snprintf((char *)deviceInfo->name, PA_WASAPI_DEVICE_NAME_LEN - 1, "WASAPI_%s:%d", (listEntry->flow == eRender ? "Output" : "Input"), index);

    // Form-factor
    wasapiDeviceInfo->formFactor = listEntry->info->formFactor;

    // Set data flow
    wasapiDeviceInfo->flow = listEntry->flow;
#endif

    // Set default Output/Input devices
    if ((defaultRenderId != NULL) && (wcsncmp(wasapiDeviceInfo->deviceId, defaultRenderId, PA_WASAPI_DEVICE_NAME_LEN - 1) == 0))
        hostApi->info.defaultOutputDevice = hostApi->info.deviceCount;
    if ((defaultCaptureId != NULL) && (wcsncmp(wasapiDeviceInfo->deviceId, defaultCaptureId, PA_WASAPI_DEVICE_NAME_LEN - 1) == 0))
        hostApi->info.defaultInputDevice = hostApi->info.deviceCount;

    // Get a temporary IAudioClient for more details
    {
        IAudioClient *tmpClient;
        WAVEFORMATEX *mixFormat;

        hr = ActivateAudioInterface(wasapiDeviceInfo, NULL, &tmpClient);
        IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);

        // Get latency
        hr = IAudioClient_GetDevicePeriod(tmpClient, &wasapiDeviceInfo->DefaultDevicePeriod, &wasapiDeviceInfo->MinimumDevicePeriod);
        if (FAILED(hr))
        {
            PA_DEBUG(("WASAPI:%d| failed getting min/default periods by IAudioClient::GetDevicePeriod() with error[%08X], will use 30000/100000 hns\n", index, (UINT32)hr));

            // assign WASAPI common values
            wasapiDeviceInfo->DefaultDevicePeriod = 100000;
            wasapiDeviceInfo->MinimumDevicePeriod = 30000;

            // ignore error, let continue further without failing with paInternalError
            hr = S_OK;
        }

        // Get mix format
        hr = IAudioClient_GetMixFormat(tmpClient, &mixFormat);
        if (SUCCEEDED(hr))
        {
            memcpy(&wasapiDeviceInfo->MixFormat, mixFormat, min(sizeof(wasapiDeviceInfo->MixFormat), (sizeof(*mixFormat) + mixFormat->cbSize)));
            CoTaskMemFree(mixFormat);
        }

        // Register WINRT device
    #ifdef PA_WINRT
        if (SUCCEEDED(hr))
        {
            // Set state
            wasapiDeviceInfo->state = DEVICE_STATE_ACTIVE;

            // Default format (Shared mode) is always a mix format
            wasapiDeviceInfo->DefaultFormat = wasapiDeviceInfo->MixFormat;
        }
    #endif

        // Release tmp client
        SAFE_RELEASE(tmpClient);

        if (hr != S_OK)
        {
            //davidv: this happened with my hardware, previously for that same device in DirectSound:
            //Digital Output (Realtek AC'97 Audio)'s GUID: {0x38f2cf50,0x7b4c,0x4740,0x86,0xeb,0xd4,0x38,0x66,0xd8,0xc8, 0x9f}
            //so something must be _really_ wrong with this device, TODO handle this better. We kind of need GetMixFormat
            LogHostError(hr);
            result = paInternalError;
            goto error;
        }
    }

    // Fill basic device data
    deviceInfo->maxInputChannels = 0;
    deviceInfo->maxOutputChannels = 0;
    deviceInfo->defaultSampleRate = wasapiDeviceInfo->MixFormat.Format.nSamplesPerSec;
    switch (wasapiDeviceInfo->flow)
    {
    case eRender: {
        deviceInfo->maxOutputChannels         = wasapiDeviceInfo->MixFormat.Format.nChannels;
        deviceInfo->defaultHighOutputLatency = nano100ToSeconds(wasapiDeviceInfo->DefaultDevicePeriod);
        deviceInfo->defaultLowOutputLatency  = nano100ToSeconds(wasapiDeviceInfo->MinimumDevicePeriod);
        PA_DEBUG(("WASAPI:%d| def.SR[%d] max.CH[%d] latency{hi[%f] lo[%f]}\n", index, (UINT32)deviceInfo->defaultSampleRate,
            deviceInfo->maxOutputChannels, (float)deviceInfo->defaultHighOutputLatency, (float)deviceInfo->defaultLowOutputLatency));
        break;}
    case eCapture: {
        deviceInfo->maxInputChannels        = wasapiDeviceInfo->MixFormat.Format.nChannels;
        deviceInfo->defaultHighInputLatency = nano100ToSeconds(wasapiDeviceInfo->DefaultDevicePeriod);
        deviceInfo->defaultLowInputLatency  = nano100ToSeconds(wasapiDeviceInfo->MinimumDevicePeriod);
        PA_DEBUG(("WASAPI:%d| def.SR[%d] max.CH[%d] latency{hi[%f] lo[%f]}\n", index, (UINT32)deviceInfo->defaultSampleRate,
            deviceInfo->maxInputChannels, (float)deviceInfo->defaultHighInputLatency, (float)deviceInfo->defaultLowInputLatency));
        break; }
    default:
        PRINT(("WASAPI:%d| bad Data Flow!\n", index));
        result = paInternalError;
        goto error;
    }

    return paNoError;

error:

    PRINT(("WASAPI: failed filling device info for device index[%d] - error[%d|%s]\n", index, result, Pa_GetErrorText(result)));

    return result;
}

// ------------------------------------------------------------------------------------------
static PaDeviceInfo *AllocateDeviceListMemory(PaWasapiHostApiRepresentation *paWasapi)
{
    PaUtilHostApiRepresentation *hostApi = (PaUtilHostApiRepresentation *)paWasapi;
    PaDeviceInfo *deviceInfoArray = NULL;

    if ((paWasapi->devInfo = (PaWasapiDeviceInfo *)PaUtil_GroupAllocateMemory(paWasapi->allocations,
        sizeof(PaWasapiDeviceInfo) * paWasapi->deviceCount)) == NULL)
    {
        return NULL;
    }
    memset(paWasapi->devInfo, 0, sizeof(PaWasapiDeviceInfo) * paWasapi->deviceCount);

    if (paWasapi->deviceCount != 0)
    {
        UINT32 i;
        UINT32 deviceCount = paWasapi->deviceCount;
    #if defined(PA_WASAPI_MAX_CONST_DEVICE_COUNT) && (PA_WASAPI_MAX_CONST_DEVICE_COUNT > 0)
        if (deviceCount < PA_WASAPI_MAX_CONST_DEVICE_COUNT)
            deviceCount = PA_WASAPI_MAX_CONST_DEVICE_COUNT;
    #endif

        if ((hostApi->deviceInfos = (PaDeviceInfo **)PaUtil_GroupAllocateMemory(paWasapi->allocations,
            sizeof(PaDeviceInfo *) * deviceCount)) == NULL)
        {
            return NULL;
        }
        for (i = 0; i < deviceCount; ++i)
            hostApi->deviceInfos[i] = NULL;

        // Allocate all device info structs in a contiguous block
        if ((deviceInfoArray = (PaDeviceInfo *)PaUtil_GroupAllocateMemory(paWasapi->allocations,
            sizeof(PaDeviceInfo) * deviceCount)) == NULL)
        {
            return NULL;
        }
        memset(deviceInfoArray, 0, sizeof(PaDeviceInfo) * deviceCount);
    }

    return deviceInfoArray;
}

// ------------------------------------------------------------------------------------------
static PaError CreateDeviceList(PaWasapiHostApiRepresentation *paWasapi, PaHostApiIndex hostApiIndex)
{
    PaUtilHostApiRepresentation *hostApi = (PaUtilHostApiRepresentation *)paWasapi;
    PaError result = paNoError;
    PaDeviceInfo *deviceInfoArray = NULL;
    UINT32 i;
    WCHAR *defaultRenderId = NULL;
    WCHAR *defaultCaptureId = NULL;
#ifndef PA_WINRT
    HRESULT hr;
    IMMDeviceCollection *pEndPoints = NULL;
    IMMDeviceEnumerator *pEnumerator = NULL;
#else
    void *pEndPoints = NULL;
    IAudioClient *tmpClient;
    PaWasapiWinrtDeviceListContext deviceListContext = { 0 };
    PaWasapiWinrtDeviceInfo defaultRender = { 0 };
    PaWasapiWinrtDeviceInfo defaultCapture = { 0 };
#endif

    // Make sure device list empty
    if ((paWasapi->deviceCount != 0) || (hostApi->info.deviceCount != 0))
        return paInternalError;

#ifndef PA_WINRT
    hr = CoCreateInstance(&pa_CLSID_IMMDeviceEnumerator, NULL, CLSCTX_INPROC_SERVER,
        &pa_IID_IMMDeviceEnumerator, (void **)&pEnumerator);
    IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);

    // Get default render and capture devices
    {
        IMMDevice *device;

        hr = IMMDeviceEnumerator_GetDefaultAudioEndpoint(pEnumerator, eRender, eMultimedia, &device);
        if (hr != S_OK)
        {
            if (hr != E_NOTFOUND)
            {
                IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);
            }
        }
        else
        {
            hr = IMMDevice_GetId(device, &defaultRenderId);
            IMMDevice_Release(device);
            IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);
        }

        hr = IMMDeviceEnumerator_GetDefaultAudioEndpoint(pEnumerator, eCapture, eMultimedia, &device);
        if (hr != S_OK)
        {
            if (hr != E_NOTFOUND)
            {
                IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);
            }
        }
        else
        {
            hr = IMMDevice_GetId(device, &defaultCaptureId);
            IMMDevice_Release(device);
            IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);
        }
    }

    // Get all currently active devices
    hr = IMMDeviceEnumerator_EnumAudioEndpoints(pEnumerator, eAll, DEVICE_STATE_ACTIVE, &pEndPoints);
    IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);

    // Get device count
    hr = IMMDeviceCollection_GetCount(pEndPoints, &paWasapi->deviceCount);
    IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);
#else
    WinRT_GetDefaultDeviceId(defaultRender.id, STATIC_ARRAY_SIZE(defaultRender.id) - 1, eRender);
    defaultRenderId = defaultRender.id;

    WinRT_GetDefaultDeviceId(defaultCapture.id, STATIC_ARRAY_SIZE(defaultCapture.id) - 1, eCapture);
    defaultCaptureId = defaultCapture.id;

    if (g_DeviceListInfo.render.deviceCount == 0)
    {
        if (SUCCEEDED(WinRT_ActivateAudioInterface(defaultRenderId, GetAudioClientIID(), &tmpClient)))
        {
            deviceListContext.devices[paWasapi->deviceCount].info = &defaultRender;
            deviceListContext.devices[paWasapi->deviceCount].flow = eRender;
            paWasapi->deviceCount++;

            SAFE_RELEASE(tmpClient);
        }
    }
    else
    {
        for (i = 0; i < g_DeviceListInfo.render.deviceCount; ++i)
        {
            deviceListContext.devices[paWasapi->deviceCount].info = &g_DeviceListInfo.render.devices[i];
            deviceListContext.devices[paWasapi->deviceCount].flow = eRender;
            paWasapi->deviceCount++;
        }
    }

    if (g_DeviceListInfo.capture.deviceCount == 0)
    {
        if (SUCCEEDED(WinRT_ActivateAudioInterface(defaultCaptureId, GetAudioClientIID(), &tmpClient)))
        {
            deviceListContext.devices[paWasapi->deviceCount].info = &defaultCapture;
            deviceListContext.devices[paWasapi->deviceCount].flow = eCapture;
            paWasapi->deviceCount++;

            SAFE_RELEASE(tmpClient);
        }
    }
    else
    {
        for (i = 0; i < g_DeviceListInfo.capture.deviceCount; ++i)
        {
            deviceListContext.devices[paWasapi->deviceCount].info = &g_DeviceListInfo.capture.devices[i];
            deviceListContext.devices[paWasapi->deviceCount].flow = eCapture;
            paWasapi->deviceCount++;
        }
    }
#endif

    // Allocate memory for the device list
    if ((paWasapi->deviceCount != 0) && ((deviceInfoArray = AllocateDeviceListMemory(paWasapi)) == NULL))
    {
        result = paInsufficientMemory;
        goto error;
    }

    // Fill WASAPI device info
    for (i = 0; i < paWasapi->deviceCount; ++i)
    {
        PaDeviceInfo *deviceInfo = &deviceInfoArray[i];

        PA_DEBUG(("WASAPI: device idx: %02d\n", i));
        PA_DEBUG(("WASAPI: ---------------\n"));

        FillBaseDeviceInfo(deviceInfo, hostApiIndex);

        if ((result = FillDeviceInfo(paWasapi, pEndPoints, i, defaultRenderId, defaultCaptureId,
            deviceInfo, &paWasapi->devInfo[i]
        #ifdef PA_WINRT
            , &deviceListContext
        #endif
            )) != paNoError)
        {
            // Faulty device is made inactive
            if ((result = FillInactiveDeviceInfo(paWasapi, deviceInfo)) != paNoError)
                goto error;
        }

        hostApi->deviceInfos[i] = deviceInfo;
        ++hostApi->info.deviceCount;
    }

    // Fill the remaining slots with inactive device info
#if defined(PA_WASAPI_MAX_CONST_DEVICE_COUNT) && (PA_WASAPI_MAX_CONST_DEVICE_COUNT > 0)
    if ((hostApi->info.deviceCount != 0) && (hostApi->info.deviceCount < PA_WASAPI_MAX_CONST_DEVICE_COUNT))
    {
        for (i = hostApi->info.deviceCount; i < PA_WASAPI_MAX_CONST_DEVICE_COUNT; ++i)
        {
            PaDeviceInfo *deviceInfo = &deviceInfoArray[i];

            FillBaseDeviceInfo(deviceInfo, hostApiIndex);

            if ((result = FillInactiveDeviceInfo(paWasapi, deviceInfo)) != paNoError)
                goto error;

            hostApi->deviceInfos[i] = deviceInfo;
            ++hostApi->info.deviceCount;
        }
    }
#endif

    // Clear any non-fatal errors
    result = paNoError;

    PRINT(("WASAPI: device list ok - found %d devices\n", paWasapi->deviceCount));

done:

#ifndef PA_WINRT
    CoTaskMemFree(defaultRenderId);
    CoTaskMemFree(defaultCaptureId);
    SAFE_RELEASE(pEndPoints);
    SAFE_RELEASE(pEnumerator);
#endif

    return result;

error:

    // Safety if error was not set so that we do not think initialize was a success
    if (result == paNoError)
        result = paInternalError;

    PRINT(("WASAPI: failed to create device list - error[%d|%s]\n", result, Pa_GetErrorText(result)));

    goto done;
}

// ------------------------------------------------------------------------------------------
PaError PaWasapi_Initialize( PaUtilHostApiRepresentation **hostApi, PaHostApiIndex hostApiIndex )
{
    PaError result;
    PaWasapiHostApiRepresentation *paWasapi;

#ifndef PA_WINRT
    if (!SetupAVRT())
    {
        PRINT(("WASAPI: No AVRT! (not VISTA?)\n"));
        return paNoError;
    }
#endif

    paWasapi = (PaWasapiHostApiRepresentation *)PaUtil_AllocateMemory(sizeof(PaWasapiHostApiRepresentation));
    if (paWasapi == NULL)
    {
        result = paInsufficientMemory;
        goto error;
    }
    memset(paWasapi, 0, sizeof(PaWasapiHostApiRepresentation)); /* ensure all fields are zeroed. especially paWasapi->allocations */

    // Initialize COM subsystem
    result = PaWinUtil_CoInitialize(paWASAPI, &paWasapi->comInitializationResult);
    if (result != paNoError)
        goto error;

    // Create memory group
    paWasapi->allocations = PaUtil_CreateAllocationGroup();
    if (paWasapi->allocations == NULL)
    {
        result = paInsufficientMemory;
        goto error;
    }

    // Fill basic interface info
    *hostApi                             = &paWasapi->inheritedHostApiRep;
    (*hostApi)->info.structVersion         = 1;
    (*hostApi)->info.type                 = paWASAPI;
    (*hostApi)->info.name                 = "Windows WASAPI";
    (*hostApi)->info.deviceCount         = 0;
    (*hostApi)->info.defaultInputDevice     = paNoDevice;
    (*hostApi)->info.defaultOutputDevice = paNoDevice;
    (*hostApi)->Terminate                = Terminate;
    (*hostApi)->OpenStream               = OpenStream;
    (*hostApi)->IsFormatSupported        = IsFormatSupported;

    // Fill the device list
    if ((result = CreateDeviceList(paWasapi, hostApiIndex)) != paNoError)
        goto error;

    // Detect if platform workaround is required
    paWasapi->useWOW64Workaround = UseWOW64Workaround();

    // Initialize time getter
    SystemTimer_InitializeTimeGetter();

    PaUtil_InitializeStreamInterface( &paWasapi->callbackStreamInterface, CloseStream, StartStream,
                                      StopStream, AbortStream, IsStreamStopped, IsStreamActive,
                                      GetStreamTime, GetStreamCpuLoad,
                                      PaUtil_DummyRead, PaUtil_DummyWrite,
                                      PaUtil_DummyGetReadAvailable, PaUtil_DummyGetWriteAvailable );

    PaUtil_InitializeStreamInterface( &paWasapi->blockingStreamInterface, CloseStream, StartStream,
                                      StopStream, AbortStream, IsStreamStopped, IsStreamActive,
                                      GetStreamTime, PaUtil_DummyGetCpuLoad,
                                      ReadStream, WriteStream, GetStreamReadAvailable, GetStreamWriteAvailable );

    PRINT(("WASAPI: initialized ok\n"));

    return paNoError;

error:

    PRINT(("WASAPI: failed %s error[%d|%s]\n", __FUNCTION__, result, Pa_GetErrorText(result)));

    Terminate((PaUtilHostApiRepresentation *)paWasapi);

    return result;
}

// ------------------------------------------------------------------------------------------
static void ReleaseWasapiDeviceInfoList( PaWasapiHostApiRepresentation *paWasapi )
{
    UINT32 i;

    // Release device info bound objects
    for (i = 0; i < paWasapi->deviceCount; ++i)
    {
    #ifndef PA_WINRT
        SAFE_RELEASE(paWasapi->devInfo[i].device);
    #endif
    }

    // Free device info
    if (paWasapi->allocations != NULL)
        PaUtil_GroupFreeMemory(paWasapi->allocations, paWasapi->devInfo);

    // Be ready for a device list reinitialization and if its creation is failed pointers must not be dangling
    paWasapi->devInfo = NULL;
    paWasapi->deviceCount = 0;
}

// ------------------------------------------------------------------------------------------
static void Terminate( PaUtilHostApiRepresentation *hostApi )
{
    PaWasapiHostApiRepresentation *paWasapi = (PaWasapiHostApiRepresentation*)hostApi;
    if (paWasapi == NULL)
        return;

    // Release device list
    ReleaseWasapiDeviceInfoList(paWasapi);

    // Free allocations and memory group itself
    if (paWasapi->allocations != NULL)
    {
        PaUtil_FreeAllAllocations(paWasapi->allocations);
        PaUtil_DestroyAllocationGroup(paWasapi->allocations);
    }

    // Release COM subsystem
    PaWinUtil_CoUninitialize(paWASAPI, &paWasapi->comInitializationResult);

    // Free API representation
    PaUtil_FreeMemory(paWasapi);

    // Close AVRT
    CloseAVRT();
}

// ------------------------------------------------------------------------------------------
static PaWasapiHostApiRepresentation *_GetHostApi(PaError *ret)
{
    PaError error;
    PaUtilHostApiRepresentation *pApi;

    if ((error = PaUtil_GetHostApiRepresentation(&pApi, paWASAPI)) != paNoError)
    {
        if (ret != NULL)
            (*ret) = error;

        return NULL;
    }

    return (PaWasapiHostApiRepresentation *)pApi;
}

// ------------------------------------------------------------------------------------------
static PaError UpdateDeviceList()
{
    int i;
    PaError ret;
    PaWasapiHostApiRepresentation *paWasapi;
    PaUtilHostApiRepresentation *hostApi;

    // Get API
    hostApi = (PaUtilHostApiRepresentation *)(paWasapi = _GetHostApi(&ret));
    if (paWasapi == NULL)
        return paNotInitialized;

    // Make sure initialized properly
    if (paWasapi->allocations == NULL)
        return paNotInitialized;

    // Release WASAPI internal device info list
    ReleaseWasapiDeviceInfoList(paWasapi);

    // Release external device info list
    if (hostApi->deviceInfos != NULL)
    {
        for (i = 0; i < hostApi->info.deviceCount; ++i)
        {
            PaUtil_GroupFreeMemory(paWasapi->allocations, (void *)hostApi->deviceInfos[i]->name);
        }
        PaUtil_GroupFreeMemory(paWasapi->allocations, hostApi->deviceInfos[0]);
        PaUtil_GroupFreeMemory(paWasapi->allocations, hostApi->deviceInfos);

        // Be ready for a device list reinitialization and if its creation is failed pointers must not be dangling
        hostApi->deviceInfos = NULL;
        hostApi->info.deviceCount = 0;
        hostApi->info.defaultInputDevice = paNoDevice;
        hostApi->info.defaultOutputDevice = paNoDevice;
    }

    // Fill possibly updated device list
    if ((ret = CreateDeviceList(paWasapi, Pa_HostApiTypeIdToHostApiIndex(paWASAPI))) != paNoError)
        return ret;

    return paNoError;
}

// ------------------------------------------------------------------------------------------
PaError PaWasapi_UpdateDeviceList()
{
#if defined(PA_WASAPI_MAX_CONST_DEVICE_COUNT) && (PA_WASAPI_MAX_CONST_DEVICE_COUNT > 0)
    return UpdateDeviceList();
#else
    return paInternalError;
#endif
}

// ------------------------------------------------------------------------------------------
int PaWasapi_GetDeviceCurrentFormat( PaStream *pStream, void *pFormat, unsigned int formatSize, int bOutput )
{
    UINT32 size;
    WAVEFORMATEXTENSIBLE *format;

    PaWasapiStream *stream = (PaWasapiStream *)pStream;
    if (stream == NULL)
        return paBadStreamPtr;

    format = (bOutput == TRUE ? &stream->out.wavex : &stream->in.wavex);

    size = min(formatSize, (UINT32)sizeof(*format));
    memcpy(pFormat, format, size);

    return size;
}

// ------------------------------------------------------------------------------------------
static PaError _GetWasapiDeviceInfoByDeviceIndex( PaWasapiDeviceInfo **info, PaDeviceIndex device )
{
    PaError ret;
    PaDeviceIndex index;

    // Get API
    PaWasapiHostApiRepresentation *paWasapi = _GetHostApi(&ret);
    if (paWasapi == NULL)
        return paNotInitialized;

    // Get device index
    if ((ret = PaUtil_DeviceIndexToHostApiDeviceIndex(&index, device, &paWasapi->inheritedHostApiRep)) != paNoError)
        return ret;

    // Validate index
    if ((UINT32)index >= paWasapi->deviceCount)
        return paInvalidDevice;

    (*info) = &paWasapi->devInfo[ index ];

    return paNoError;
}

// ------------------------------------------------------------------------------------------
int PaWasapi_GetDeviceDefaultFormat( void *pFormat, unsigned int formatSize, PaDeviceIndex device )
{
    PaError ret;
    PaWasapiDeviceInfo *deviceInfo;
    UINT32 size;

    if (pFormat == NULL)
        return paBadBufferPtr;
    if (formatSize <= 0)
        return paBufferTooSmall;

    if ((ret = _GetWasapiDeviceInfoByDeviceIndex(&deviceInfo, device)) != paNoError)
        return ret;

    size = min(formatSize, (UINT32)sizeof(deviceInfo->DefaultFormat));
    memcpy(pFormat, &deviceInfo->DefaultFormat, size);

    return size;
}

// ------------------------------------------------------------------------------------------
int PaWasapi_GetDeviceMixFormat( void *pFormat, unsigned int formatSize, PaDeviceIndex device )
{
    PaError ret;
    PaWasapiDeviceInfo *deviceInfo;
    UINT32 size;

    if (pFormat == NULL)
        return paBadBufferPtr;
    if (formatSize <= 0)
        return paBufferTooSmall;

    if ((ret = _GetWasapiDeviceInfoByDeviceIndex(&deviceInfo, device)) != paNoError)
        return ret;

    size = min(formatSize, (UINT32)sizeof(deviceInfo->MixFormat));
    memcpy(pFormat, &deviceInfo->MixFormat, size);

    return size;
}

// ------------------------------------------------------------------------------------------
int PaWasapi_GetDeviceRole( PaDeviceIndex device )
{
    PaError ret;
    PaWasapiDeviceInfo *deviceInfo;

    if ((ret = _GetWasapiDeviceInfoByDeviceIndex(&deviceInfo, device)) != paNoError)
        return ret;

    return deviceInfo->formFactor;
}

// ------------------------------------------------------------------------------------------
PaError PaWasapi_GetIMMDevice( PaDeviceIndex device, void **pIMMDevice )
{
#ifndef PA_WINRT
    PaError ret;
    PaWasapiDeviceInfo *deviceInfo;

    if (pIMMDevice == NULL)
        return paBadBufferPtr;

    if ((ret = _GetWasapiDeviceInfoByDeviceIndex(&deviceInfo, device)) != paNoError)
        return ret;

    (*pIMMDevice) = deviceInfo->device;

    return paNoError;
#else
    (void)device;
    (void)pIMMDevice;
    return paIncompatibleStreamHostApi;
#endif
}

// ------------------------------------------------------------------------------------------
PaError PaWasapi_GetFramesPerHostBuffer( PaStream *pStream, unsigned int *pInput, unsigned int *pOutput )
{
    PaWasapiStream *stream = (PaWasapiStream *)pStream;
    if (stream == NULL)
        return paBadStreamPtr;

    if (pInput != NULL)
        (*pInput) = stream->in.framesPerHostCallback;

    if (pOutput != NULL)
        (*pOutput) = stream->out.framesPerHostCallback;

    return paNoError;
}

// ------------------------------------------------------------------------------------------
static void LogWAVEFORMATEXTENSIBLE(const WAVEFORMATEXTENSIBLE *in)
{
    const WAVEFORMATEX *old = (WAVEFORMATEX *)in;
    switch (old->wFormatTag)
    {
    case WAVE_FORMAT_EXTENSIBLE: {

        PRINT(("wFormatTag     =WAVE_FORMAT_EXTENSIBLE\n"));

        if (IsEqualGUID(&in->SubFormat, &pa_KSDATAFORMAT_SUBTYPE_IEEE_FLOAT))
        {
            PRINT(("SubFormat      =KSDATAFORMAT_SUBTYPE_IEEE_FLOAT\n"));
        }
        else
        if (IsEqualGUID(&in->SubFormat, &pa_KSDATAFORMAT_SUBTYPE_PCM))
        {
            PRINT(("SubFormat      =KSDATAFORMAT_SUBTYPE_PCM\n"));
        }
        else
        {
            PRINT(("SubFormat      =CUSTOM GUID{%d:%d:%d:%d%d%d%d%d%d%d%d}\n",
                                        in->SubFormat.Data1,
                                        in->SubFormat.Data2,
                                        in->SubFormat.Data3,
                                        (int)in->SubFormat.Data4[0],
                                        (int)in->SubFormat.Data4[1],
                                        (int)in->SubFormat.Data4[2],
                                        (int)in->SubFormat.Data4[3],
                                        (int)in->SubFormat.Data4[4],
                                        (int)in->SubFormat.Data4[5],
                                        (int)in->SubFormat.Data4[6],
                                        (int)in->SubFormat.Data4[7]));
        }
        PRINT(("Samples.wValidBitsPerSample =%d\n",  in->Samples.wValidBitsPerSample));
        PRINT(("dwChannelMask  =0x%X\n",in->dwChannelMask));

        break; }

    case WAVE_FORMAT_PCM:        PRINT(("wFormatTag     =WAVE_FORMAT_PCM\n")); break;
    case WAVE_FORMAT_IEEE_FLOAT: PRINT(("wFormatTag     =WAVE_FORMAT_IEEE_FLOAT\n")); break;
    default:
        PRINT(("wFormatTag     =UNKNOWN(%d)\n",old->wFormatTag)); break;
    }

    PRINT(("nChannels      =%d\n",old->nChannels));
    PRINT(("nSamplesPerSec =%d\n",old->nSamplesPerSec));
    PRINT(("nAvgBytesPerSec=%d\n",old->nAvgBytesPerSec));
    PRINT(("nBlockAlign    =%d\n",old->nBlockAlign));
    PRINT(("wBitsPerSample =%d\n",old->wBitsPerSample));
    PRINT(("cbSize         =%d\n",old->cbSize));
}

// ------------------------------------------------------------------------------------------
PaSampleFormat WaveToPaFormat(const WAVEFORMATEXTENSIBLE *fmtext)
{
    const WAVEFORMATEX *fmt = (WAVEFORMATEX *)fmtext;

    switch (fmt->wFormatTag)
    {
    case WAVE_FORMAT_EXTENSIBLE: {
        if (IsEqualGUID(&fmtext->SubFormat, &pa_KSDATAFORMAT_SUBTYPE_IEEE_FLOAT))
        {
            if (fmtext->Samples.wValidBitsPerSample == 32)
                return paFloat32;
        }
        else
        if (IsEqualGUID(&fmtext->SubFormat, &pa_KSDATAFORMAT_SUBTYPE_PCM))
        {
            switch (fmt->wBitsPerSample)
            {
            case 32: return paInt32;
            case 24: return paInt24;
            case 16: return paInt16;
            case  8: return paUInt8;
            }
        }
        break; }

    case WAVE_FORMAT_IEEE_FLOAT:
        return paFloat32;

    case WAVE_FORMAT_PCM: {
        switch (fmt->wBitsPerSample)
        {
        case 32: return paInt32;
        case 24: return paInt24;
        case 16: return paInt16;
        case  8: return paUInt8;
        }
        break; }
    }

    return paCustomFormat;
}

// ------------------------------------------------------------------------------------------
static PaError MakeWaveFormatFromParams(WAVEFORMATEXTENSIBLE *wavex, const PaStreamParameters *params,
    double sampleRate, BOOL packedOnly)
{
    WORD bitsPerSample;
    WAVEFORMATEX *old;
    DWORD channelMask = 0;
    BOOL useExtensible = (params->channelCount > 2); // format is always forced for >2 channels format
    PaWasapiStreamInfo *streamInfo = (PaWasapiStreamInfo *)params->hostApiSpecificStreamInfo;

    // Convert PaSampleFormat to valid data bits
    if ((bitsPerSample = PaSampleFormatToBitsPerSample(params->sampleFormat)) == 0)
        return paSampleFormatNotSupported;

    // Use user assigned channel mask
    if ((streamInfo != NULL) && (streamInfo->flags & paWinWasapiUseChannelMask))
    {
        channelMask   = streamInfo->channelMask;
        useExtensible = TRUE;
    }

    memset(wavex, 0, sizeof(*wavex));

    old                    = (WAVEFORMATEX *)wavex;
    old->nChannels      = (WORD)params->channelCount;
    old->nSamplesPerSec = (DWORD)sampleRate;
    old->wBitsPerSample = bitsPerSample;

    // according to MSDN for WAVEFORMATEX structure for WAVE_FORMAT_PCM:
    // "If wFormatTag is WAVE_FORMAT_PCM, then wBitsPerSample should be equal to 8 or 16."
    if ((bitsPerSample != 8) && (bitsPerSample != 16))
    {
        // Normally 20 or 24 bits must go in 32 bit containers (ints) but in Exclusive mode some devices require
        // packed version of the format, e.g. for example 24-bit in 3-bytes
        old->wBitsPerSample = (packedOnly ? bitsPerSample : 32);
        useExtensible       = TRUE;
    }

    // WAVEFORMATEX
    if (!useExtensible)
    {
        old->wFormatTag    = WAVE_FORMAT_PCM;
    }
    // WAVEFORMATEXTENSIBLE
    else
    {
        old->wFormatTag = WAVE_FORMAT_EXTENSIBLE;
        old->cbSize        = sizeof(WAVEFORMATEXTENSIBLE) - sizeof(WAVEFORMATEX);

        if ((params->sampleFormat & ~paNonInterleaved) == paFloat32)
            wavex->SubFormat = pa_KSDATAFORMAT_SUBTYPE_IEEE_FLOAT;
        else
            wavex->SubFormat = pa_KSDATAFORMAT_SUBTYPE_PCM;

        wavex->Samples.wValidBitsPerSample = bitsPerSample;

        // Set channel mask
        if (channelMask != 0)
        {
            wavex->dwChannelMask = channelMask;
        }
        else
        {
            switch (params->channelCount)
            {
            case 1:  wavex->dwChannelMask = PAWIN_SPEAKER_MONO; break;
            case 2:  wavex->dwChannelMask = PAWIN_SPEAKER_STEREO; break;
            case 3:  wavex->dwChannelMask = PAWIN_SPEAKER_STEREO|SPEAKER_LOW_FREQUENCY; break;
            case 4:  wavex->dwChannelMask = PAWIN_SPEAKER_QUAD; break;
            case 5:  wavex->dwChannelMask = PAWIN_SPEAKER_QUAD|SPEAKER_LOW_FREQUENCY; break;
#ifdef PAWIN_SPEAKER_5POINT1_SURROUND
            case 6:  wavex->dwChannelMask = PAWIN_SPEAKER_5POINT1_SURROUND; break;
#else
            case 6:  wavex->dwChannelMask = PAWIN_SPEAKER_5POINT1; break;
#endif
#ifdef PAWIN_SPEAKER_5POINT1_SURROUND
            case 7:  wavex->dwChannelMask = PAWIN_SPEAKER_5POINT1_SURROUND|SPEAKER_BACK_CENTER; break;
#else
            case 7:  wavex->dwChannelMask = PAWIN_SPEAKER_5POINT1|SPEAKER_BACK_CENTER; break;
#endif
#ifdef PAWIN_SPEAKER_7POINT1_SURROUND
            case 8:  wavex->dwChannelMask = PAWIN_SPEAKER_7POINT1_SURROUND; break;
#else
            case 8:  wavex->dwChannelMask = PAWIN_SPEAKER_7POINT1; break;
#endif

            default: wavex->dwChannelMask = 0;
            }
        }
    }

    old->nBlockAlign     = old->nChannels * (old->wBitsPerSample / 8);
    old->nAvgBytesPerSec = old->nSamplesPerSec * old->nBlockAlign;

    return paNoError;
}

// ------------------------------------------------------------------------------------------
static HRESULT GetAlternativeSampleFormatExclusive(IAudioClient *client, double sampleRate,
    const PaStreamParameters *params, WAVEFORMATEXTENSIBLE *outWavex, BOOL packedSampleFormatOnly)
{
    HRESULT hr = !S_OK;
    AUDCLNT_SHAREMODE shareMode = AUDCLNT_SHAREMODE_EXCLUSIVE;
    WAVEFORMATEXTENSIBLE testFormat;
    PaStreamParameters testParams;
    int i;
    static const PaSampleFormat bestToWorst[] = { paInt32, paInt24, paFloat32, paInt16 };

    // Try combination Stereo (2 channels) and then we will use our custom mono-stereo mixer
    if (params->channelCount == 1)
    {
        testParams = (*params);
        testParams.channelCount = 2;

        if (MakeWaveFormatFromParams(&testFormat, &testParams, sampleRate, packedSampleFormatOnly) == paNoError)
        {
            if ((hr = IAudioClient_IsFormatSupported(client, shareMode, &testFormat.Format, NULL)) == S_OK)
            {
                (*outWavex) = testFormat;
                return hr;
            }
        }

        // Try selecting suitable sample type
        for (i = 0; i < STATIC_ARRAY_SIZE(bestToWorst); ++i)
        {
            testParams.sampleFormat = bestToWorst[i];

            if (MakeWaveFormatFromParams(&testFormat, &testParams, sampleRate, packedSampleFormatOnly) == paNoError)
            {
                if ((hr = IAudioClient_IsFormatSupported(client, shareMode, &testFormat.Format, NULL)) == S_OK)
                {
                    (*outWavex) = testFormat;
                    return hr;
                }
            }
        }
    }

    // Try selecting suitable sample type
    testParams = (*params);
    for (i = 0; i < STATIC_ARRAY_SIZE(bestToWorst); ++i)
    {
        testParams.sampleFormat = bestToWorst[i];

        if (MakeWaveFormatFromParams(&testFormat, &testParams, sampleRate, packedSampleFormatOnly) == paNoError)
        {
            if ((hr = IAudioClient_IsFormatSupported(client, shareMode, &testFormat.Format, NULL)) == S_OK)
            {
                (*outWavex) = testFormat;
                return hr;
            }
        }
    }

    return hr;
}

// ------------------------------------------------------------------------------------------
static PaError GetClosestFormat(IAudioClient *client, double sampleRate, const PaStreamParameters *_params,
    AUDCLNT_SHAREMODE shareMode, WAVEFORMATEXTENSIBLE *outWavex, BOOL output)
{
    PaWasapiStreamInfo *streamInfo   = (PaWasapiStreamInfo *)_params->hostApiSpecificStreamInfo;
    WAVEFORMATEX *sharedClosestMatch = NULL;
    HRESULT hr                       = !S_OK;
    PaStreamParameters params        = (*_params);
    const BOOL explicitFormat        = (streamInfo != NULL) && ((streamInfo->flags & paWinWasapiExplicitSampleFormat) == paWinWasapiExplicitSampleFormat);
    (void)output;

    /* It was not noticed that 24-bit Input producing no output while device accepts this format.
       To fix this issue let's ask for 32-bits and let PA converters convert host 32-bit data
       to 24-bit for user-space. The bug concerns Vista, if Windows 7 supports 24-bits for Input
       please report to PortAudio developers to exclude Windows 7.
    */
    /*if ((params.sampleFormat == paInt24) && (output == FALSE))
        params.sampleFormat = paFloat32;*/ // <<< The silence was due to missing Int32_To_Int24_Dither implementation

    // Try standard approach, e.g. if data is > 16 bits it will be packed into 32-bit containers
    MakeWaveFormatFromParams(outWavex, &params, sampleRate, FALSE);

    // If built-in PCM converter requested then shared mode format will always succeed
    if ((GetWindowsVersion() >= WINDOWS_7_SERVER2008R2) &&
        (shareMode == AUDCLNT_SHAREMODE_SHARED) &&
        ((streamInfo != NULL) && (streamInfo->flags & paWinWasapiAutoConvert)))
        return paFormatIsSupported;

    hr = IAudioClient_IsFormatSupported(client, shareMode, &outWavex->Format, (shareMode == AUDCLNT_SHAREMODE_SHARED ? &sharedClosestMatch : NULL));

    // Exclusive mode can require packed format for some devices
    if ((hr != S_OK) && (shareMode == AUDCLNT_SHAREMODE_EXCLUSIVE))
    {
        // Enforce packed only format, e.g. data bits will not be packed into 32-bit containers in any case
        MakeWaveFormatFromParams(outWavex, &params, sampleRate, TRUE);
        hr = IAudioClient_IsFormatSupported(client, shareMode, &outWavex->Format, NULL);
    }

    if (hr == S_OK)
    {
        return paFormatIsSupported;
    }
    else
    if (sharedClosestMatch != NULL)
    {
        WORD bitsPerSample;

        if (sharedClosestMatch->wFormatTag == WAVE_FORMAT_EXTENSIBLE)
            memcpy(outWavex, sharedClosestMatch, sizeof(WAVEFORMATEXTENSIBLE));
        else
            memcpy(outWavex, sharedClosestMatch, sizeof(WAVEFORMATEX));

        CoTaskMemFree(sharedClosestMatch);
        sharedClosestMatch = NULL;

        // Validate SampleRate
        if ((DWORD)sampleRate != outWavex->Format.nSamplesPerSec)
            return paInvalidSampleRate;

        // Validate Channel count
        if ((WORD)params.channelCount != outWavex->Format.nChannels)
        {
            // If mono, then driver does not support 1 channel, we use internal workaround
            // of tiny software mixing functionality, e.g. we provide to user buffer 1 channel
            // but then mix into 2 for device buffer
            if ((params.channelCount == 1) && (outWavex->Format.nChannels == 2))
                return paFormatIsSupported;
            else
                return paInvalidChannelCount;
        }

        // Validate Sample format
        if ((bitsPerSample = PaSampleFormatToBitsPerSample(params.sampleFormat)) == 0)
            return paSampleFormatNotSupported;

        // Accepted format
        return paFormatIsSupported;
    }
    else
    if ((shareMode == AUDCLNT_SHAREMODE_EXCLUSIVE) && !explicitFormat)
    {
        // Try standard approach, e.g. if data is > 16 bits it will be packed into 32-bit containers
        if ((hr = GetAlternativeSampleFormatExclusive(client, sampleRate, &params, outWavex, FALSE)) == S_OK)
            return paFormatIsSupported;

        // Enforce packed only format, e.g. data bits will not be packed into 32-bit containers in any case
        if ((hr = GetAlternativeSampleFormatExclusive(client, sampleRate, &params, outWavex, TRUE)) == S_OK)
            return paFormatIsSupported;

        // Log failure
        LogHostError(hr);
    }
    else
    {
        // Exclusive mode and requested strict format, WASAPI did not accept this sample format
        LogHostError(hr);
    }

    return paInvalidSampleRate;
}

// ------------------------------------------------------------------------------------------
static PaError IsStreamParamsValid(struct PaUtilHostApiRepresentation *hostApi,
                                   const  PaStreamParameters *inputParameters,
                                   const  PaStreamParameters *outputParameters,
                                   double sampleRate)
{
    if (hostApi == NULL)
        return paHostApiNotFound;
    if ((UINT32)sampleRate == 0)
        return paInvalidSampleRate;

    if (inputParameters != NULL)
    {
        /* all standard sample formats are supported by the buffer adapter,
            this implementation doesn't support any custom sample formats */
        // Note: paCustomFormat is now 8.24 (24-bits in 32-bit containers)
        //if (inputParameters->sampleFormat & paCustomFormat)
        //    return paSampleFormatNotSupported;

        /* unless alternate device specification is supported, reject the use of
            paUseHostApiSpecificDeviceSpecification */
        if (inputParameters->device == paUseHostApiSpecificDeviceSpecification)
            return paInvalidDevice;

        /* check that input device can support inputChannelCount */
        if (inputParameters->channelCount > hostApi->deviceInfos[ inputParameters->device ]->maxInputChannels)
            return paInvalidChannelCount;

        /* validate inputStreamInfo */
        if (inputParameters->hostApiSpecificStreamInfo)
        {
            PaWasapiStreamInfo *inputStreamInfo = (PaWasapiStreamInfo *)inputParameters->hostApiSpecificStreamInfo;
            if ((inputStreamInfo->size != sizeof(PaWasapiStreamInfo)) ||
                (inputStreamInfo->version != 1) ||
                (inputStreamInfo->hostApiType != paWASAPI))
            {
                return paIncompatibleHostApiSpecificStreamInfo;
            }
        }

        return paNoError;
    }

    if (outputParameters != NULL)
    {
        /* all standard sample formats are supported by the buffer adapter,
            this implementation doesn't support any custom sample formats */
        // Note: paCustomFormat is now 8.24 (24-bits in 32-bit containers)
        //if (outputParameters->sampleFormat & paCustomFormat)
        //    return paSampleFormatNotSupported;

        /* unless alternate device specification is supported, reject the use of
            paUseHostApiSpecificDeviceSpecification */
        if (outputParameters->device == paUseHostApiSpecificDeviceSpecification)
            return paInvalidDevice;

        /* check that output device can support outputChannelCount */
        if (outputParameters->channelCount > hostApi->deviceInfos[ outputParameters->device ]->maxOutputChannels)
            return paInvalidChannelCount;

        /* validate outputStreamInfo */
        if(outputParameters->hostApiSpecificStreamInfo)
        {
            PaWasapiStreamInfo *outputStreamInfo = (PaWasapiStreamInfo *)outputParameters->hostApiSpecificStreamInfo;
            if ((outputStreamInfo->size != sizeof(PaWasapiStreamInfo)) ||
                (outputStreamInfo->version != 1) ||
                (outputStreamInfo->hostApiType != paWASAPI))
            {
                return paIncompatibleHostApiSpecificStreamInfo;
            }
        }

        return paNoError;
    }

    return (inputParameters || outputParameters ? paNoError : paInternalError);
}

// ------------------------------------------------------------------------------------------
static PaError IsFormatSupported( struct PaUtilHostApiRepresentation *hostApi,
                                  const  PaStreamParameters *inputParameters,
                                  const  PaStreamParameters *outputParameters,
                                  double sampleRate )
{
    IAudioClient *tmpClient = NULL;
    PaWasapiHostApiRepresentation *paWasapi = (PaWasapiHostApiRepresentation*)hostApi;
    PaWasapiStreamInfo *inputStreamInfo = NULL, *outputStreamInfo = NULL;

    // Validate PaStreamParameters
    PaError error;
    if ((error = IsStreamParamsValid(hostApi, inputParameters, outputParameters, sampleRate)) != paNoError)
        return error;

    if (inputParameters != NULL)
    {
        WAVEFORMATEXTENSIBLE wavex;
        HRESULT hr;
        PaError answer;
        AUDCLNT_SHAREMODE shareMode = AUDCLNT_SHAREMODE_SHARED;
        inputStreamInfo = (PaWasapiStreamInfo *)inputParameters->hostApiSpecificStreamInfo;

        if (inputStreamInfo && (inputStreamInfo->flags & paWinWasapiExclusive))
            shareMode = AUDCLNT_SHAREMODE_EXCLUSIVE;

        hr = ActivateAudioInterface(&paWasapi->devInfo[inputParameters->device], inputStreamInfo, &tmpClient);
        if (hr != S_OK)
        {
            LogHostError(hr);
            return paInvalidDevice;
        }

        answer = GetClosestFormat(tmpClient, sampleRate, inputParameters, shareMode, &wavex, FALSE);
        SAFE_RELEASE(tmpClient);

        if (answer != paFormatIsSupported)
            return answer;
    }

    if (outputParameters != NULL)
    {
        HRESULT hr;
        WAVEFORMATEXTENSIBLE wavex;
        PaError answer;
        AUDCLNT_SHAREMODE shareMode = AUDCLNT_SHAREMODE_SHARED;
        outputStreamInfo = (PaWasapiStreamInfo *)outputParameters->hostApiSpecificStreamInfo;

        if (outputStreamInfo && (outputStreamInfo->flags & paWinWasapiExclusive))
            shareMode = AUDCLNT_SHAREMODE_EXCLUSIVE;

        hr = ActivateAudioInterface(&paWasapi->devInfo[outputParameters->device], outputStreamInfo, &tmpClient);
        if (hr != S_OK)
        {
            LogHostError(hr);
            return paInvalidDevice;
        }

        answer = GetClosestFormat(tmpClient, sampleRate, outputParameters, shareMode, &wavex, TRUE);
        SAFE_RELEASE(tmpClient);

        if (answer != paFormatIsSupported)
            return answer;
    }

    return paFormatIsSupported;
}

// ------------------------------------------------------------------------------------------
static PaUint32 _GetFramesPerHostBuffer(PaUint32 userFramesPerBuffer, PaTime suggestedLatency, double sampleRate, PaUint32 TimerJitterMs)
{
    PaUint32 frames = userFramesPerBuffer + max( userFramesPerBuffer, (PaUint32)(suggestedLatency * sampleRate) );
    frames += (PaUint32)((sampleRate * 0.001) * TimerJitterMs);
    return frames;
}

// ------------------------------------------------------------------------------------------
static void _RecalculateBuffersCount(PaWasapiSubStream *sub, UINT32 userFramesPerBuffer, UINT32 framesPerLatency,
    BOOL fullDuplex, BOOL output)
{
    // Count buffers (must be at least 1)
    sub->buffers = (userFramesPerBuffer != 0 ? framesPerLatency / userFramesPerBuffer : 1);
    if (sub->buffers == 0)
        sub->buffers = 1;

    // Determine number of buffers used:
    // - Full-duplex mode will lead to period difference, thus only 1
    // - Input mode, only 1, as WASAPI allows extraction of only 1 packet
    // - For Shared mode we use double buffering
    if ((sub->shareMode == AUDCLNT_SHAREMODE_EXCLUSIVE) || fullDuplex)
    {
        BOOL eventMode = ((sub->streamFlags & AUDCLNT_STREAMFLAGS_EVENTCALLBACK) == AUDCLNT_STREAMFLAGS_EVENTCALLBACK);

        // Exclusive mode does not allow >1 buffers be used for Event interface, e.g. GetBuffer
        // call must acquire max buffer size and it all must be processed.
        if (eventMode)
            sub->userBufferAndHostMatch = 1;

        // Full-duplex or Event mode: prefer paUtilBoundedHostBufferSize because exclusive mode will starve
        // and produce glitchy audio
        // Output Polling mode: prefer paUtilFixedHostBufferSize (buffers != 1) for polling mode is it allows
        // to consume user data by fixed size data chunks and thus lowers memory movement (less CPU usage)
        if (fullDuplex || eventMode || !output)
            sub->buffers = 1;
    }
}

// ------------------------------------------------------------------------------------------
static void _CalculateAlignedPeriod(PaWasapiSubStream *pSub, UINT32 *nFramesPerLatency, ALIGN_FUNC pAlignFunc)
{
    // Align frames to HD Audio packet size of 128 bytes for Exclusive mode only.
    // Not aligning on Windows Vista will cause Event timeout, although Windows 7 will
    // return AUDCLNT_E_BUFFER_SIZE_NOT_ALIGNED error to realign buffer. Aligning is necessary
    // for Exclusive mode only! when audio data is fed directly to hardware.
    if (pSub->shareMode == AUDCLNT_SHAREMODE_EXCLUSIVE)
    {
        (*nFramesPerLatency) = AlignFramesPerBuffer((*nFramesPerLatency),
            pSub->wavex.Format.nBlockAlign, pAlignFunc);
    }

    // Calculate period
    pSub->period = MakeHnsPeriod((*nFramesPerLatency), pSub->wavex.Format.nSamplesPerSec);
}

// ------------------------------------------------------------------------------------------
static void _CalculatePeriodicity(PaWasapiSubStream *pSub, BOOL output, REFERENCE_TIME *periodicity)
{
    // Note: according to Microsoft docs for IAudioClient::Initialize we can set periodicity of the buffer
    // only for Exclusive mode. By setting periodicity almost equal to the user buffer frames we can
    // achieve high quality (less glitchy) low-latency audio.
    if (pSub->shareMode == AUDCLNT_SHAREMODE_EXCLUSIVE)
    {
        const PaWasapiDeviceInfo *pInfo = pSub->params.device_info;

        // By default periodicity equals to the full buffer (legacy PA WASAPI's behavior)
        (*periodicity) = pSub->period;

        // Try make buffer ready for I/O once we request the buffer readiness for it. Only Polling mode
        // because for Event mode buffer size and periodicity must be equal according to Microsoft
        // documentation for IAudioClient::Initialize.
        //
        // TO-DO: try spread to capture and full-duplex cases (not tested and therefore disabled)
        //
        if (((pSub->streamFlags & AUDCLNT_STREAMFLAGS_EVENTCALLBACK) == 0) &&
            (output && !pSub->params.full_duplex))
        {
            UINT32 alignedFrames;
            REFERENCE_TIME userPeriodicity;

            // Align frames backwards, so device will likely make buffer read ready when we are ready
            // to read it (our scheduling will wait for amount of millisoconds of frames_per_buffer)
            alignedFrames = AlignFramesPerBuffer(pSub->params.frames_per_buffer,
                pSub->wavex.Format.nBlockAlign, ALIGN_BWD);

            userPeriodicity = MakeHnsPeriod(alignedFrames, pSub->wavex.Format.nSamplesPerSec);

            // Must not be larger than buffer size
            if (userPeriodicity > pSub->period)
                userPeriodicity = pSub->period;

            // Must not be smaller than minimum supported by the device
            if (userPeriodicity < pInfo->MinimumDevicePeriod)
                userPeriodicity = pInfo->MinimumDevicePeriod;

            (*periodicity) = userPeriodicity;
        }
    }
    else
        (*periodicity) = 0;
}

// ------------------------------------------------------------------------------------------
static HRESULT CreateAudioClient(PaWasapiStream *pStream, PaWasapiSubStream *pSub, BOOL output, PaError *pa_error)
{
    PaError error;
    HRESULT hr;
    const PaWasapiDeviceInfo *pInfo  = pSub->params.device_info;
    const PaStreamParameters *params = &pSub->params.stream_params;
    const double sampleRate          = pSub->params.sample_rate;
    const BOOL fullDuplex            = pSub->params.full_duplex;
    const UINT32 userFramesPerBuffer = pSub->params.frames_per_buffer;
    UINT32 framesPerLatency          = userFramesPerBuffer;
    IAudioClient *audioClient        = NULL;
    REFERENCE_TIME eventPeriodicity  = 0;

    // Assume default failure due to some reason
    (*pa_error) = paInvalidDevice;

    // Validate parameters
    if (!pSub || !pInfo || !params)
    {
        (*pa_error) = paBadStreamPtr;
        return E_POINTER;
    }
    if ((UINT32)sampleRate == 0)
    {
        (*pa_error) = paInvalidSampleRate;
        return E_INVALIDARG;
    }

    // Get the audio client
    if (FAILED(hr = ActivateAudioInterface(pInfo, &pSub->params.wasapi_params, &audioClient)))
    {
        (*pa_error) = paInsufficientMemory;
        LogHostError(hr);
        goto done;
    }

    // Get closest format
    if ((error = GetClosestFormat(audioClient, sampleRate, params, pSub->shareMode, &pSub->wavex, output)) != paFormatIsSupported)
    {
        (*pa_error) = error;
        LogHostError(hr = AUDCLNT_E_UNSUPPORTED_FORMAT);
        goto done; // fail, format not supported
    }

    // Check for Mono <<>> Stereo workaround
    if ((params->channelCount == 1) && (pSub->wavex.Format.nChannels == 2))
    {
        // select mixer
        pSub->monoMixer = GetMonoToStereoMixer(&pSub->wavex, (pInfo->flow == eRender ? MIX_DIR__1TO2 : MIX_DIR__2TO1_L));
        if (pSub->monoMixer == NULL)
        {
            (*pa_error) = paInvalidChannelCount;
            LogHostError(hr = AUDCLNT_E_UNSUPPORTED_FORMAT);
            goto done; // fail, no mixer for format
        }
    }

    // Calculate host buffer size
    if ((pSub->shareMode != AUDCLNT_SHAREMODE_EXCLUSIVE) &&
        (!pSub->streamFlags || ((pSub->streamFlags & AUDCLNT_STREAMFLAGS_EVENTCALLBACK) == 0)))
    {
        framesPerLatency = _GetFramesPerHostBuffer(userFramesPerBuffer,
            params->suggestedLatency, pSub->wavex.Format.nSamplesPerSec, 0/*,
            (pSub->streamFlags & AUDCLNT_STREAMFLAGS_EVENTCALLBACK ? 0 : 1)*/);
    }
    else
    {
    #ifdef PA_WASAPI_FORCE_POLL_IF_LARGE_BUFFER
        REFERENCE_TIME overall;
    #endif

        // Work 1:1 with user buffer (only polling allows to use >1)
        framesPerLatency += MakeFramesFromHns(SecondsTonano100(params->suggestedLatency), pSub->wavex.Format.nSamplesPerSec);

        // Force Polling if overall latency is >= 21.33ms as it allows to use 100% CPU in a callback,
        // or user specified latency parameter.
    #ifdef PA_WASAPI_FORCE_POLL_IF_LARGE_BUFFER
        overall = MakeHnsPeriod(framesPerLatency, pSub->wavex.Format.nSamplesPerSec);
        if (overall >= (106667 * 2)/*21.33ms*/)
        {
            framesPerLatency = _GetFramesPerHostBuffer(userFramesPerBuffer,
                params->suggestedLatency, pSub->wavex.Format.nSamplesPerSec, 0/*,
                (streamFlags & AUDCLNT_STREAMFLAGS_EVENTCALLBACK ? 0 : 1)*/);

            // Use Polling interface
            pSub->streamFlags &= ~AUDCLNT_STREAMFLAGS_EVENTCALLBACK;
            PRINT(("WASAPI: CreateAudioClient: forcing POLL mode\n"));
        }
    #endif
    }

    // For full-duplex output resize buffer to be the same as for input
    if (output && fullDuplex)
        framesPerLatency = pStream->in.framesPerHostCallback;

    // Avoid 0 frames
    if (framesPerLatency == 0)
        framesPerLatency = MakeFramesFromHns(pInfo->DefaultDevicePeriod, pSub->wavex.Format.nSamplesPerSec);

    // Exclusive Input stream renders data in 6 packets, we must set then the size of
    // single packet, total buffer size, e.g. required latency will be PacketSize * 6
    if (!output && (pSub->shareMode == AUDCLNT_SHAREMODE_EXCLUSIVE))
    {
        // Do it only for Polling mode
        if ((pSub->streamFlags & AUDCLNT_STREAMFLAGS_EVENTCALLBACK) == 0)
            framesPerLatency /= WASAPI_PACKETS_PER_INPUT_BUFFER;
    }

    // Calculate aligned period
    _CalculateAlignedPeriod(pSub, &framesPerLatency, ALIGN_BWD);

    /*! Enforce min/max period for device in Shared mode to avoid bad audio quality.
        Avoid doing so for Exclusive mode as alignment will suffer.
    */
    if (pSub->shareMode == AUDCLNT_SHAREMODE_SHARED)
    {
        if (pSub->period < pInfo->DefaultDevicePeriod)
        {
            pSub->period = pInfo->DefaultDevicePeriod;

            // Recalculate aligned period
            framesPerLatency = MakeFramesFromHns(pSub->period, pSub->wavex.Format.nSamplesPerSec);
            _CalculateAlignedPeriod(pSub, &framesPerLatency, ALIGN_BWD);
        }
    }
    else
    {
        if (pSub->period < pInfo->MinimumDevicePeriod)
        {
            pSub->period = pInfo->MinimumDevicePeriod;

            // Recalculate aligned period
            framesPerLatency = MakeFramesFromHns(pSub->period, pSub->wavex.Format.nSamplesPerSec);
            _CalculateAlignedPeriod(pSub, &framesPerLatency, ALIGN_FWD);
        }
    }

    /*! Windows 7 does not allow to set latency lower than minimal device period and will
        return error: AUDCLNT_E_INVALID_DEVICE_PERIOD. Under Vista we enforce the same behavior
        manually for unified behavior on all platforms.
    */
    {
        /*!    AUDCLNT_E_BUFFER_SIZE_ERROR: Applies to Windows 7 and later.
            Indicates that the buffer duration value requested by an exclusive-mode client is
            out of range. The requested duration value for pull mode must not be greater than
            500 milliseconds; for push mode the duration value must not be greater than 2 seconds.
        */
        if (pSub->shareMode == AUDCLNT_SHAREMODE_EXCLUSIVE)
        {
            static const REFERENCE_TIME MAX_BUFFER_EVENT_DURATION = 500  * 10000;
            static const REFERENCE_TIME MAX_BUFFER_POLL_DURATION  = 2000 * 10000;

            // Pull mode, max 500ms
            if (pSub->streamFlags & AUDCLNT_STREAMFLAGS_EVENTCALLBACK)
            {
                if (pSub->period > MAX_BUFFER_EVENT_DURATION)
                {
                    pSub->period = MAX_BUFFER_EVENT_DURATION;

                    // Recalculate aligned period
                    framesPerLatency = MakeFramesFromHns(pSub->period, pSub->wavex.Format.nSamplesPerSec);
                    _CalculateAlignedPeriod(pSub, &framesPerLatency, ALIGN_BWD);
                }
            }
            // Push mode, max 2000ms
            else
            {
                if (pSub->period > MAX_BUFFER_POLL_DURATION)
                {
                    pSub->period = MAX_BUFFER_POLL_DURATION;

                    // Recalculate aligned period
                    framesPerLatency = MakeFramesFromHns(pSub->period, pSub->wavex.Format.nSamplesPerSec);
                    _CalculateAlignedPeriod(pSub, &framesPerLatency, ALIGN_BWD);
                }
            }
        }
    }

    // Set device scheduling period (always 0 in Shared mode according to Microsoft docs)
    _CalculatePeriodicity(pSub, output, &eventPeriodicity);

    // Open the stream and associate it with an audio session
    hr = IAudioClient_Initialize(audioClient,
        pSub->shareMode,
        pSub->streamFlags,
        pSub->period,
        eventPeriodicity,
        &pSub->wavex.Format,
        NULL);

    // [Output only] Check if buffer size is the one we requested in Exclusive mode, for UAC1 USB DACs WASAPI
    // can allocate internal buffer equal to 8 times of pSub->period that has to be corrected in order to match
    // the requested latency
    if (output && SUCCEEDED(hr) && (pSub->shareMode == AUDCLNT_SHAREMODE_EXCLUSIVE))
    {
        UINT32 maxBufferFrames;

        if (FAILED(hr = IAudioClient_GetBufferSize(audioClient, &maxBufferFrames)))
        {
            (*pa_error) = paInvalidDevice;
            LogHostError(hr);
            goto done;
        }

        // For Exclusive mode for UAC1 devices maxBufferFrames may be framesPerLatency * 8 but check any difference
        // to be able to guarantee the latency user requested and also resulted framesPerLatency may be bigger than
        // 2 seconds that will cause audio client not operational (GetCurrentPadding() will return always 0)
        if (maxBufferFrames >= (framesPerLatency * 2))
        {
            UINT32 ratio = maxBufferFrames / framesPerLatency;

            PRINT(("WASAPI: CreateAudioClient: detected %d times larger buffer than requested, correct to match user latency\n", ratio));

            // Get new aligned frames lowered by calculated ratio
            framesPerLatency = MakeFramesFromHns(pSub->period / ratio, pSub->wavex.Format.nSamplesPerSec);
            _CalculateAlignedPeriod(pSub, &framesPerLatency, ALIGN_BWD);

            // Make sure we are not below the minimum period
            if (pSub->period < pInfo->MinimumDevicePeriod)
                pSub->period = pInfo->MinimumDevicePeriod;

            // Release previous client
            SAFE_RELEASE(audioClient);

            // Create a new audio client
            if (FAILED(hr = ActivateAudioInterface(pInfo, &pSub->params.wasapi_params, &audioClient)))
            {
                (*pa_error) = paInsufficientMemory;
                LogHostError(hr);
                goto done;
            }

            // Set device scheduling period (always 0 in Shared mode according to Microsoft docs)
            _CalculatePeriodicity(pSub, output, &eventPeriodicity);

            // Open the stream and associate it with an audio session
            hr = IAudioClient_Initialize(audioClient,
                pSub->shareMode,
                pSub->streamFlags,
                pSub->period,
                eventPeriodicity,
                &pSub->wavex.Format,
                NULL);
        }
    }

    /*! WASAPI is tricky on large device buffer, sometimes 2000ms can be allocated sometimes
        less. There is no known guaranteed level thus we make subsequent tries by decreasing
        buffer by 100ms per try.
    */
    while ((hr == E_OUTOFMEMORY) && (pSub->period > (100 * 10000)))
    {
        PRINT(("WASAPI: CreateAudioClient: decreasing buffer size to %d milliseconds\n", (pSub->period / 10000)));

        // Decrease by 100ms and try again
        pSub->period -= (100 * 10000);

        // Recalculate aligned period
        framesPerLatency = MakeFramesFromHns(pSub->period, pSub->wavex.Format.nSamplesPerSec);
        _CalculateAlignedPeriod(pSub, &framesPerLatency, ALIGN_BWD);

        // Release the previous allocations
        SAFE_RELEASE(audioClient);

        // Create a new audio client
        if (FAILED(hr = ActivateAudioInterface(pInfo, &pSub->params.wasapi_params, &audioClient)))
        {
            (*pa_error) = paInsufficientMemory;
            LogHostError(hr);
            goto done;
        }

        // Set device scheduling period (always 0 in Shared mode according to Microsoft docs)
        _CalculatePeriodicity(pSub, output, &eventPeriodicity);

        // Open the stream and associate it with an audio session
        hr = IAudioClient_Initialize(audioClient,
            pSub->shareMode,
            pSub->streamFlags,
            pSub->period,
            eventPeriodicity,
            &pSub->wavex.Format,
            NULL);
    }

    /*! WASAPI buffer size or alignment failure. Fallback to using default size and alignment.
    */
    if ((hr == AUDCLNT_E_BUFFER_SIZE_ERROR) || (hr == AUDCLNT_E_BUFFER_SIZE_NOT_ALIGNED))
    {
        // Use default
        pSub->period = pInfo->DefaultDevicePeriod;

        PRINT(("WASAPI: CreateAudioClient: correcting buffer size/alignment to device default\n"));

        // Release the previous allocations
        SAFE_RELEASE(audioClient);

        // Create a new audio client
        if (FAILED(hr = ActivateAudioInterface(pInfo, &pSub->params.wasapi_params, &audioClient)))
        {
            (*pa_error) = paInsufficientMemory;
            LogHostError(hr);
            goto done;
        }

        // Set device scheduling period (always 0 in Shared mode according to Microsoft docs)
        _CalculatePeriodicity(pSub, output, &eventPeriodicity);

        // Open the stream and associate it with an audio session
        hr = IAudioClient_Initialize(audioClient,
            pSub->shareMode,
            pSub->streamFlags,
            pSub->period,
            eventPeriodicity,
            &pSub->wavex.Format,
            NULL);
    }

    // Error has no workaround, fail completely
    if (FAILED(hr))
    {
        (*pa_error) = paInvalidDevice;
        LogHostError(hr);
        goto done;
    }

    // Set client
    pSub->clientParent = audioClient;
    IAudioClient_AddRef(pSub->clientParent);

    // Recalculate buffers count
    _RecalculateBuffersCount(pSub, userFramesPerBuffer, MakeFramesFromHns(pSub->period, pSub->wavex.Format.nSamplesPerSec),
        fullDuplex, output);

    // No error, client is successfully created
    (*pa_error) = paNoError;

done:

    // Clean up
    SAFE_RELEASE(audioClient);
    return hr;
}

// ------------------------------------------------------------------------------------------
static PaError ActivateAudioClientOutput(PaWasapiStream *stream)
{
    HRESULT hr;
    PaError result;
    UINT32 maxBufferSize;
    PaTime bufferLatency;
    const UINT32 framesPerBuffer = stream->out.params.frames_per_buffer;

    // Create Audio client
    if (FAILED(hr = CreateAudioClient(stream, &stream->out, TRUE, &result)))
    {
        LogPaError(result);
        goto error;
    }
    LogWAVEFORMATEXTENSIBLE(&stream->out.wavex);

    // Activate volume
    stream->outVol = NULL;
    /*hr = info->device->Activate(
        __uuidof(IAudioEndpointVolume), CLSCTX_INPROC_SERVER, NULL,
        (void**)&stream->outVol);
    if (hr != S_OK)
        return paInvalidDevice;*/

    // Get max possible buffer size to check if it is not less than that we request
    if (FAILED(hr = IAudioClient_GetBufferSize(stream->out.clientParent, &maxBufferSize)))
    {
        LogHostError(hr);
        LogPaError(result = paInvalidDevice);
        goto error;
    }

    // Correct buffer to max size if it maxed out result of GetBufferSize
    stream->out.bufferSize = maxBufferSize;

    // Number of frames that are required at each period
    stream->out.framesPerHostCallback = maxBufferSize;

    // Calculate frames per single buffer, if buffers > 1 then always framesPerBuffer
    stream->out.framesPerBuffer =
        (stream->out.userBufferAndHostMatch ? stream->out.framesPerHostCallback : framesPerBuffer);

    // Calculate buffer latency
    bufferLatency = (PaTime)maxBufferSize / stream->out.wavex.Format.nSamplesPerSec;

    // Append buffer latency to interface latency in shared mode (see GetStreamLatency notes)
    stream->out.latencySeconds = bufferLatency;

    PRINT(("WASAPI::OpenStream(output): framesPerUser[ %d ] framesPerHost[ %d ] latency[ %.02fms ] exclusive[ %s ] wow64_fix[ %s ] mode[ %s ]\n", (UINT32)framesPerBuffer, (UINT32)stream->out.framesPerHostCallback, (float)(stream->out.latencySeconds*1000.0f), (stream->out.shareMode == AUDCLNT_SHAREMODE_EXCLUSIVE ? "YES" : "NO"), (stream->out.params.wow64_workaround ? "YES" : "NO"), (stream->out.streamFlags & AUDCLNT_STREAMFLAGS_EVENTCALLBACK ? "EVENT" : "POLL")));

    return paNoError;

error:

    return result;
}

// ------------------------------------------------------------------------------------------
static PaError ActivateAudioClientInput(PaWasapiStream *stream)
{
    HRESULT hr;
    PaError result;
    UINT32 maxBufferSize;
    PaTime bufferLatency;
    const UINT32 framesPerBuffer = stream->in.params.frames_per_buffer;

    // Create Audio client
    if (FAILED(hr = CreateAudioClient(stream, &stream->in, FALSE, &result)))
    {
        LogPaError(result);
        goto error;
    }
    LogWAVEFORMATEXTENSIBLE(&stream->in.wavex);

    // Create volume mgr
    stream->inVol = NULL;
    /*hr = info->device->Activate(
        __uuidof(IAudioEndpointVolume), CLSCTX_INPROC_SERVER, NULL,
        (void**)&stream->inVol);
    if (hr != S_OK)
        return paInvalidDevice;*/

    // Get max possible buffer size to check if it is not less than that we request
    if (FAILED(hr = IAudioClient_GetBufferSize(stream->in.clientParent, &maxBufferSize)))
    {
        LogHostError(hr);
        LogPaError(result = paInvalidDevice);
        goto error;
    }

    // Correct buffer to max size if it maxed out result of GetBufferSize
    stream->in.bufferSize = maxBufferSize;

    // Get interface latency (actually unneeded as we calculate latency from the size
    // of maxBufferSize).
    if (FAILED(hr = IAudioClient_GetStreamLatency(stream->in.clientParent, &stream->in.deviceLatency)))
    {
        LogHostError(hr);
        LogPaError(result = paInvalidDevice);
        goto error;
    }
    //stream->in.latencySeconds = nano100ToSeconds(stream->in.deviceLatency);

    // Number of frames that are required at each period
    stream->in.framesPerHostCallback = maxBufferSize;

    // Calculate frames per single buffer, if buffers > 1 then always framesPerBuffer
    stream->in.framesPerBuffer =
        (stream->in.userBufferAndHostMatch ? stream->in.framesPerHostCallback : framesPerBuffer);

    // Calculate buffer latency
    bufferLatency = (PaTime)maxBufferSize / stream->in.wavex.Format.nSamplesPerSec;

    // Append buffer latency to interface latency in shared mode (see GetStreamLatency notes)
    stream->in.latencySeconds = bufferLatency;

    PRINT(("WASAPI::OpenStream(input): framesPerUser[ %d ] framesPerHost[ %d ] latency[ %.02fms ] exclusive[ %s ] wow64_fix[ %s ] mode[ %s ]\n", (UINT32)framesPerBuffer, (UINT32)stream->in.framesPerHostCallback, (float)(stream->in.latencySeconds*1000.0f), (stream->in.shareMode == AUDCLNT_SHAREMODE_EXCLUSIVE ? "YES" : "NO"), (stream->in.params.wow64_workaround ? "YES" : "NO"), (stream->in.streamFlags & AUDCLNT_STREAMFLAGS_EVENTCALLBACK ? "EVENT" : "POLL")));

    return paNoError;

error:

    return result;
}

// ------------------------------------------------------------------------------------------
static PaError OpenStream( struct PaUtilHostApiRepresentation *hostApi,
                           PaStream** s,
                           const PaStreamParameters *inputParameters,
                           const PaStreamParameters *outputParameters,
                           double sampleRate,
                           unsigned long framesPerBuffer,
                           PaStreamFlags streamFlags,
                           PaStreamCallback *streamCallback,
                           void *userData )
{
    PaError result = paNoError;
    HRESULT hr;
    PaWasapiHostApiRepresentation *paWasapi = (PaWasapiHostApiRepresentation*)hostApi;
    PaWasapiStream *stream = NULL;
    int inputChannelCount, outputChannelCount;
    PaSampleFormat inputSampleFormat, outputSampleFormat;
    PaSampleFormat hostInputSampleFormat, hostOutputSampleFormat;
    PaWasapiStreamInfo *inputStreamInfo = NULL, *outputStreamInfo = NULL;
    PaWasapiDeviceInfo *info = NULL;
    ULONG framesPerHostCallback;
    PaUtilHostBufferSizeMode bufferMode;
    const BOOL fullDuplex = ((inputParameters != NULL) && (outputParameters != NULL));
    BOOL useInputBufferProcessor = (inputParameters != NULL), useOutputBufferProcessor = (outputParameters != NULL);

    // validate PaStreamParameters
    if ((result = IsStreamParamsValid(hostApi, inputParameters, outputParameters, sampleRate)) != paNoError)
        return LogPaError(result);

    // Validate platform specific flags
    if ((streamFlags & paPlatformSpecificFlags) != 0)
    {
        LogPaError(result = paInvalidFlag); /* unexpected platform specific flag */
        goto error;
    }

    // Allocate memory for PaWasapiStream
    if ((stream = (PaWasapiStream *)PaUtil_AllocateMemory(sizeof(PaWasapiStream))) == NULL)
    {
        LogPaError(result = paInsufficientMemory);
        goto error;
    }

    // Default thread priority is Audio: for exclusive mode we will use Pro Audio.
    stream->nThreadPriority = eThreadPriorityAudio;

    // Set default number of frames: paFramesPerBufferUnspecified
    if (framesPerBuffer == paFramesPerBufferUnspecified)
    {
        UINT32 framesPerBufferIn  = 0, framesPerBufferOut = 0;
        if (inputParameters != NULL)
        {
            info = &paWasapi->devInfo[inputParameters->device];
            framesPerBufferIn = MakeFramesFromHns(info->DefaultDevicePeriod, (UINT32)sampleRate);
        }
        if (outputParameters != NULL)
        {
            info = &paWasapi->devInfo[outputParameters->device];
            framesPerBufferOut = MakeFramesFromHns(info->DefaultDevicePeriod, (UINT32)sampleRate);
        }
        // choosing maximum default size
        framesPerBuffer = max(framesPerBufferIn, framesPerBufferOut);
    }
    if (framesPerBuffer == 0)
        framesPerBuffer = ((UINT32)sampleRate / 100) * 2;

    // Try create device: Input
    if (inputParameters != NULL)
    {
        inputChannelCount = inputParameters->channelCount;
        inputSampleFormat = GetSampleFormatForIO(inputParameters->sampleFormat);
        info              = &paWasapi->devInfo[inputParameters->device];

        // default Shared Mode
        stream->in.shareMode = AUDCLNT_SHAREMODE_SHARED;

        // PaWasapiStreamInfo
        if (inputParameters->hostApiSpecificStreamInfo != NULL)
        {
            memcpy(&stream->in.params.wasapi_params, inputParameters->hostApiSpecificStreamInfo, min(sizeof(stream->in.params.wasapi_params), ((PaWasapiStreamInfo *)inputParameters->hostApiSpecificStreamInfo)->size));
            stream->in.params.wasapi_params.size = sizeof(stream->in.params.wasapi_params);

            stream->in.params.stream_params.hostApiSpecificStreamInfo = &stream->in.params.wasapi_params;
            inputStreamInfo = &stream->in.params.wasapi_params;

            stream->in.flags = inputStreamInfo->flags;

            // Exclusive Mode
            if (inputStreamInfo->flags & paWinWasapiExclusive)
            {
                // Boost thread priority
                stream->nThreadPriority = eThreadPriorityProAudio;
                // Make Exclusive
                stream->in.shareMode = AUDCLNT_SHAREMODE_EXCLUSIVE;
            }

            // explicit thread priority level
            if (inputStreamInfo->flags & paWinWasapiThreadPriority)
            {
                if ((inputStreamInfo->threadPriority > eThreadPriorityNone) &&
                    (inputStreamInfo->threadPriority <= eThreadPriorityWindowManager))
                    stream->nThreadPriority = inputStreamInfo->threadPriority;
            }

            // redirect processing to custom user callback, ignore PA buffer processor
            useInputBufferProcessor = !(inputStreamInfo->flags & paWinWasapiRedirectHostProcessor);
        }

        // Choose processing mode
        stream->in.streamFlags = (stream->in.shareMode == AUDCLNT_SHAREMODE_EXCLUSIVE ? AUDCLNT_STREAMFLAGS_EVENTCALLBACK : 0);
        if (paWasapi->useWOW64Workaround)
            stream->in.streamFlags = 0; // polling interface
        else
        if (streamCallback == NULL)
            stream->in.streamFlags = 0; // polling interface
        else
        if ((inputStreamInfo != NULL) && (inputStreamInfo->flags & paWinWasapiPolling))
            stream->in.streamFlags = 0; // polling interface
        else
        if (fullDuplex)
            stream->in.streamFlags = 0; // polling interface is implemented for full-duplex mode also

        // Use built-in PCM converter (channel count and sample rate) if requested
        if ((GetWindowsVersion() >= WINDOWS_7_SERVER2008R2) &&
            (stream->in.shareMode == AUDCLNT_SHAREMODE_SHARED) &&
            ((inputStreamInfo != NULL) && (inputStreamInfo->flags & paWinWasapiAutoConvert)))
            stream->in.streamFlags |= (AUDCLNT_STREAMFLAGS_AUTOCONVERTPCM | AUDCLNT_STREAMFLAGS_SRC_DEFAULT_QUALITY);

        // Fill parameters for Audio Client creation
        stream->in.params.device_info       = info;
        stream->in.params.stream_params     = (*inputParameters);
        stream->in.params.frames_per_buffer = framesPerBuffer;
        stream->in.params.sample_rate       = sampleRate;
        stream->in.params.blocking          = (streamCallback == NULL);
        stream->in.params.full_duplex       = fullDuplex;
        stream->in.params.wow64_workaround  = paWasapi->useWOW64Workaround;

        // Create and activate audio client
        if ((result = ActivateAudioClientInput(stream)) != paNoError)
        {
            LogPaError(result);
            goto error;
        }

        // Get closest format
        hostInputSampleFormat = PaUtil_SelectClosestAvailableFormat(WaveToPaFormat(&stream->in.wavex), inputSampleFormat);

        // Set user-side custom host processor
        if ((inputStreamInfo != NULL) &&
            (inputStreamInfo->flags & paWinWasapiRedirectHostProcessor))
        {
            stream->hostProcessOverrideInput.processor = inputStreamInfo->hostProcessorInput;
            stream->hostProcessOverrideInput.userData = userData;
        }

        // Only get IAudioCaptureClient input once here instead of getting it at multiple places based on the use
        if (FAILED(hr = IAudioClient_GetService(stream->in.clientParent, &pa_IID_IAudioCaptureClient, (void **)&stream->captureClientParent)))
        {
            LogHostError(hr);
            LogPaError(result = paUnanticipatedHostError);
            goto error;
        }

        // Create ring buffer for blocking mode (It is needed because we fetch Input packets, not frames,
        // and thus we have to save partial packet if such remains unread)
        if (stream->in.params.blocking == TRUE)
        {
            UINT32 bufferFrames = ALIGN_NEXT_POW2((stream->in.framesPerHostCallback / WASAPI_PACKETS_PER_INPUT_BUFFER) * 2);
            UINT32 frameSize    = stream->in.wavex.Format.nBlockAlign;

            // buffer
            if ((stream->in.tailBuffer = PaUtil_AllocateMemory(sizeof(PaUtilRingBuffer))) == NULL)
            {
                LogPaError(result = paInsufficientMemory);
                goto error;
            }
            memset(stream->in.tailBuffer, 0, sizeof(PaUtilRingBuffer));

            // buffer memory region
            stream->in.tailBufferMemory = PaUtil_AllocateMemory(frameSize * bufferFrames);
            if (stream->in.tailBufferMemory == NULL)
            {
                LogPaError(result = paInsufficientMemory);
                goto error;
            }

            // initialize
            if (PaUtil_InitializeRingBuffer(stream->in.tailBuffer, frameSize, bufferFrames,    stream->in.tailBufferMemory) != 0)
            {
                LogPaError(result = paInternalError);
                goto error;
            }
        }
    }
    else
    {
        inputChannelCount = 0;
        inputSampleFormat = hostInputSampleFormat = paInt16; /* Suppress 'uninitialised var' warnings. */
    }

    // Try create device: Output
    if (outputParameters != NULL)
    {
        outputChannelCount = outputParameters->channelCount;
        outputSampleFormat = GetSampleFormatForIO(outputParameters->sampleFormat);
        info               = &paWasapi->devInfo[outputParameters->device];

        // default Shared Mode
        stream->out.shareMode = AUDCLNT_SHAREMODE_SHARED;

        // set PaWasapiStreamInfo
        if (outputParameters->hostApiSpecificStreamInfo != NULL)
        {
            memcpy(&stream->out.params.wasapi_params, outputParameters->hostApiSpecificStreamInfo, min(sizeof(stream->out.params.wasapi_params), ((PaWasapiStreamInfo *)outputParameters->hostApiSpecificStreamInfo)->size));
            stream->out.params.wasapi_params.size = sizeof(stream->out.params.wasapi_params);

            stream->out.params.stream_params.hostApiSpecificStreamInfo = &stream->out.params.wasapi_params;
            outputStreamInfo = &stream->out.params.wasapi_params;

            stream->out.flags = outputStreamInfo->flags;

            // Exclusive Mode
            if (outputStreamInfo->flags & paWinWasapiExclusive)
            {
                // Boost thread priority
                stream->nThreadPriority = eThreadPriorityProAudio;
                // Make Exclusive
                stream->out.shareMode = AUDCLNT_SHAREMODE_EXCLUSIVE;
            }

            // explicit thread priority level
            if (outputStreamInfo->flags & paWinWasapiThreadPriority)
            {
                if ((outputStreamInfo->threadPriority > eThreadPriorityNone) &&
                    (outputStreamInfo->threadPriority <= eThreadPriorityWindowManager))
                    stream->nThreadPriority = outputStreamInfo->threadPriority;
            }

            // redirect processing to custom user callback, ignore PA buffer processor
            useOutputBufferProcessor = !(outputStreamInfo->flags & paWinWasapiRedirectHostProcessor);
        }

        // Choose processing mode
        stream->out.streamFlags = (stream->out.shareMode == AUDCLNT_SHAREMODE_EXCLUSIVE ? AUDCLNT_STREAMFLAGS_EVENTCALLBACK : 0);
        if (paWasapi->useWOW64Workaround)
            stream->out.streamFlags = 0; // polling interface
        else
        if (streamCallback == NULL)
            stream->out.streamFlags = 0; // polling interface
        else
        if ((outputStreamInfo != NULL) && (outputStreamInfo->flags & paWinWasapiPolling))
            stream->out.streamFlags = 0; // polling interface
        else
        if (fullDuplex)
            stream->out.streamFlags = 0; // polling interface is implemented for full-duplex mode also

        // Use built-in PCM converter (channel count and sample rate) if requested
        if ((GetWindowsVersion() >= WINDOWS_7_SERVER2008R2) &&
            (stream->out.shareMode == AUDCLNT_SHAREMODE_SHARED) &&
            ((outputStreamInfo != NULL) && (outputStreamInfo->flags & paWinWasapiAutoConvert)))
            stream->out.streamFlags |= (AUDCLNT_STREAMFLAGS_AUTOCONVERTPCM | AUDCLNT_STREAMFLAGS_SRC_DEFAULT_QUALITY);

        // Fill parameters for Audio Client creation
        stream->out.params.device_info       = info;
        stream->out.params.stream_params     = (*outputParameters);
        stream->out.params.frames_per_buffer = framesPerBuffer;
        stream->out.params.sample_rate       = sampleRate;
        stream->out.params.blocking          = (streamCallback == NULL);
        stream->out.params.full_duplex       = fullDuplex;
        stream->out.params.wow64_workaround  = paWasapi->useWOW64Workaround;

        // Create and activate audio client
        if ((result = ActivateAudioClientOutput(stream)) != paNoError)
        {
            LogPaError(result);
            goto error;
        }

        // Get closest format
        hostOutputSampleFormat = PaUtil_SelectClosestAvailableFormat(WaveToPaFormat(&stream->out.wavex), outputSampleFormat);

        // Set user-side custom host processor
        if ((outputStreamInfo != NULL) &&
            (outputStreamInfo->flags & paWinWasapiRedirectHostProcessor))
        {
            stream->hostProcessOverrideOutput.processor = outputStreamInfo->hostProcessorOutput;
            stream->hostProcessOverrideOutput.userData = userData;
        }

        // Only get IAudioCaptureClient output once here instead of getting it at multiple places based on the use
        if (FAILED(hr = IAudioClient_GetService(stream->out.clientParent, &pa_IID_IAudioRenderClient, (void **)&stream->renderClientParent)))
        {
            LogHostError(hr);
            LogPaError(result = paUnanticipatedHostError);
            goto error;
        }
    }
    else
    {
        outputChannelCount = 0;
        outputSampleFormat = hostOutputSampleFormat = paInt16; /* Suppress 'uninitialized var' warnings. */
    }

    // log full-duplex
    if (fullDuplex)
        PRINT(("WASAPI::OpenStream: full-duplex mode\n"));

    // paWinWasapiPolling must be on/or not on both streams
    if ((inputParameters != NULL) && (outputParameters != NULL))
    {
        if ((inputStreamInfo != NULL) && (outputStreamInfo != NULL))
        {
            if (((inputStreamInfo->flags & paWinWasapiPolling) &&
                !(outputStreamInfo->flags & paWinWasapiPolling))
                ||
                (!(inputStreamInfo->flags & paWinWasapiPolling) &&
                 (outputStreamInfo->flags & paWinWasapiPolling)))
            {
                LogPaError(result = paInvalidFlag);
                goto error;
            }
        }
    }

    // Initialize stream representation
    if (streamCallback)
    {
        stream->bBlocking = FALSE;
        PaUtil_InitializeStreamRepresentation(&stream->streamRepresentation,
                                              &paWasapi->callbackStreamInterface,
                                              streamCallback, userData);
    }
    else
    {
        stream->bBlocking = TRUE;
        PaUtil_InitializeStreamRepresentation(&stream->streamRepresentation,
                                              &paWasapi->blockingStreamInterface,
                                              streamCallback, userData);
    }

    // Initialize CPU measurer
    PaUtil_InitializeCpuLoadMeasurer(&stream->cpuLoadMeasurer, sampleRate);

    if (outputParameters && inputParameters)
    {
        // serious problem #1 - No, Not a problem, especially concerning Exclusive mode.
        // Input device in exclusive mode somehow is getting large buffer always, thus we
        // adjust Output latency to reflect it, thus period will differ but playback will be
        // normal.
        /*if (stream->in.period != stream->out.period)
        {
            PRINT(("WASAPI: OpenStream: period discrepancy\n"));
            LogPaError(result = paBadIODeviceCombination);
            goto error;
        }*/

        // serious problem #2 - No, Not a problem, as framesPerHostCallback take into account
        // sample size while it is not a problem for PA full-duplex, we must care of
        // period only!
        /*if (stream->out.framesPerHostCallback != stream->in.framesPerHostCallback)
        {
            PRINT(("WASAPI: OpenStream: framesPerHostCallback discrepancy\n"));
            goto error;
        }*/
    }

    // Calculate frames per host for processor
    framesPerHostCallback = (outputParameters ? stream->out.framesPerBuffer : stream->in.framesPerBuffer);

    // Choose correct mode of buffer processing:
    // Exclusive/Shared non paWinWasapiPolling mode: paUtilFixedHostBufferSize - always fixed
    // Exclusive/Shared paWinWasapiPolling mode: paUtilBoundedHostBufferSize - may vary for Exclusive or Full-duplex
    bufferMode = paUtilFixedHostBufferSize;
    if (inputParameters) // !!! WASAPI IAudioCaptureClient::GetBuffer extracts not number of frames but 1 packet, thus we always must adapt
        bufferMode = paUtilBoundedHostBufferSize;
    else
    if (outputParameters)
    {
        if ((stream->out.buffers == 1) &&
            (!stream->out.streamFlags || ((stream->out.streamFlags & AUDCLNT_STREAMFLAGS_EVENTCALLBACK) == 0)))
            bufferMode = paUtilBoundedHostBufferSize;
    }
    stream->bufferMode = bufferMode;

    // Initialize buffer processor
    if (useInputBufferProcessor || useOutputBufferProcessor)
    {
        result =  PaUtil_InitializeBufferProcessor(
            &stream->bufferProcessor,
            inputChannelCount,
            inputSampleFormat,
            hostInputSampleFormat,
            outputChannelCount,
            outputSampleFormat,
            hostOutputSampleFormat,
            sampleRate,
            streamFlags,
            framesPerBuffer,
            framesPerHostCallback,
            bufferMode,
            streamCallback,
            userData);
        if (result != paNoError)
        {
            LogPaError(result);
            goto error;
        }
    }

    // Set Input latency
    stream->streamRepresentation.streamInfo.inputLatency =
            (useInputBufferProcessor ? PaUtil_GetBufferProcessorInputLatencyFrames(&stream->bufferProcessor) / sampleRate : 0)
            + (inputParameters != NULL ? stream->in.latencySeconds : 0);

    // Set Output latency
    stream->streamRepresentation.streamInfo.outputLatency =
            (useOutputBufferProcessor ? PaUtil_GetBufferProcessorOutputLatencyFrames(&stream->bufferProcessor) / sampleRate : 0)
            + (outputParameters != NULL ? stream->out.latencySeconds : 0);

    // Set SR
    stream->streamRepresentation.streamInfo.sampleRate = sampleRate;

    (*s) = (PaStream *)stream;
    return result;

error:

    if (stream != NULL)
        CloseStream(stream);

    return result;
}

// ------------------------------------------------------------------------------------------
static PaError CloseStream( PaStream* s )
{
    PaError result = paNoError;
    PaWasapiStream *stream = (PaWasapiStream*)s;

    // abort active stream
    if (IsStreamActive(s))
    {
        result = AbortStream(s);
    }

    SAFE_RELEASE(stream->captureClientParent);
    SAFE_RELEASE(stream->renderClientParent);
    SAFE_RELEASE(stream->out.clientParent);
    SAFE_RELEASE(stream->in.clientParent);
    SAFE_RELEASE(stream->inVol);
    SAFE_RELEASE(stream->outVol);

    CloseHandle(stream->event[S_INPUT]);
    CloseHandle(stream->event[S_OUTPUT]);

    _StreamCleanup(stream);

    PaWasapi_FreeMemory(stream->in.monoBuffer);
    PaWasapi_FreeMemory(stream->out.monoBuffer);

    PaUtil_FreeMemory(stream->in.tailBuffer);
    PaUtil_FreeMemory(stream->in.tailBufferMemory);

    PaUtil_FreeMemory(stream->out.tailBuffer);
    PaUtil_FreeMemory(stream->out.tailBufferMemory);

    PaUtil_TerminateBufferProcessor(&stream->bufferProcessor);
    PaUtil_TerminateStreamRepresentation(&stream->streamRepresentation);
    PaUtil_FreeMemory(stream);

    return result;
}

// ------------------------------------------------------------------------------------------
HRESULT UnmarshalSubStreamComPointers(PaWasapiSubStream *substream)
{
#ifndef PA_WINRT
    HRESULT hResult = S_OK;
    HRESULT hFirstBadResult = S_OK;
    substream->clientProc = NULL;

    // IAudioClient
    hResult = CoGetInterfaceAndReleaseStream(substream->clientStream, GetAudioClientIID(), (LPVOID*)&substream->clientProc);
    substream->clientStream = NULL;
    if (hResult != S_OK)
    {
        hFirstBadResult = (hFirstBadResult == S_OK) ? hResult : hFirstBadResult;
    }

    return hFirstBadResult;

#else
    (void)substream;
    return S_OK;
#endif
}

// ------------------------------------------------------------------------------------------
HRESULT UnmarshalStreamComPointers(PaWasapiStream *stream)
{
#ifndef PA_WINRT
    HRESULT hResult = S_OK;
    HRESULT hFirstBadResult = S_OK;
    stream->captureClient = NULL;
    stream->renderClient = NULL;
    stream->in.clientProc = NULL;
    stream->out.clientProc = NULL;

    if (NULL != stream->in.clientParent)
    {
        // SubStream pointers
        hResult = UnmarshalSubStreamComPointers(&stream->in);
        if (hResult != S_OK)
        {
            hFirstBadResult = (hFirstBadResult == S_OK) ? hResult : hFirstBadResult;
        }

        // IAudioCaptureClient
        hResult = CoGetInterfaceAndReleaseStream(stream->captureClientStream, &pa_IID_IAudioCaptureClient, (LPVOID*)&stream->captureClient);
        stream->captureClientStream = NULL;
        if (hResult != S_OK)
        {
            hFirstBadResult = (hFirstBadResult == S_OK) ? hResult : hFirstBadResult;
        }
    }

    if (NULL != stream->out.clientParent)
    {
        // SubStream pointers
        hResult = UnmarshalSubStreamComPointers(&stream->out);
        if (hResult != S_OK)
        {
            hFirstBadResult = (hFirstBadResult == S_OK) ? hResult : hFirstBadResult;
        }

        // IAudioRenderClient
        hResult = CoGetInterfaceAndReleaseStream(stream->renderClientStream, &pa_IID_IAudioRenderClient, (LPVOID*)&stream->renderClient);
        stream->renderClientStream = NULL;
        if (hResult != S_OK)
        {
            hFirstBadResult = (hFirstBadResult == S_OK) ? hResult : hFirstBadResult;
        }
    }

    return hFirstBadResult;
#else
    if (stream->in.clientParent != NULL)
    {
        stream->in.clientProc = stream->in.clientParent;
        IAudioClient_AddRef(stream->in.clientParent);
    }

    if (stream->out.clientParent != NULL)
    {
        stream->out.clientProc = stream->out.clientParent;
        IAudioClient_AddRef(stream->out.clientParent);
    }

    if (stream->renderClientParent != NULL)
    {
        stream->renderClient = stream->renderClientParent;
        IAudioRenderClient_AddRef(stream->renderClientParent);
    }

    if (stream->captureClientParent != NULL)
    {
        stream->captureClient = stream->captureClientParent;
        IAudioCaptureClient_AddRef(stream->captureClientParent);
    }

    return S_OK;
#endif
}

// -----------------------------------------------------------------------------------------
void ReleaseUnmarshaledSubComPointers(PaWasapiSubStream *substream)
{
    SAFE_RELEASE(substream->clientProc);
}

// -----------------------------------------------------------------------------------------
void ReleaseUnmarshaledComPointers(PaWasapiStream *stream)
{
    // Release AudioClient services first
    SAFE_RELEASE(stream->captureClient);
    SAFE_RELEASE(stream->renderClient);

    // Release AudioClients
    ReleaseUnmarshaledSubComPointers(&stream->in);
    ReleaseUnmarshaledSubComPointers(&stream->out);
}

// ------------------------------------------------------------------------------------------
HRESULT MarshalSubStreamComPointers(PaWasapiSubStream *substream)
{
#ifndef PA_WINRT
    HRESULT hResult;
    substream->clientStream = NULL;

    // IAudioClient
    hResult = CoMarshalInterThreadInterfaceInStream(GetAudioClientIID(), (LPUNKNOWN)substream->clientParent, &substream->clientStream);
    if (hResult != S_OK)
        goto marshal_sub_error;

    return hResult;

    // If marshaling error occurred, make sure to release everything.
marshal_sub_error:

    UnmarshalSubStreamComPointers(substream);
    ReleaseUnmarshaledSubComPointers(substream);
    return hResult;
#else
    (void)substream;
    return S_OK;
#endif
}

// ------------------------------------------------------------------------------------------
HRESULT MarshalStreamComPointers(PaWasapiStream *stream)
{
#ifndef PA_WINRT
    HRESULT hResult = S_OK;
    stream->captureClientStream = NULL;
    stream->in.clientStream = NULL;
    stream->renderClientStream = NULL;
    stream->out.clientStream = NULL;

    if (NULL != stream->in.clientParent)
    {
        // SubStream pointers
        hResult = MarshalSubStreamComPointers(&stream->in);
        if (hResult != S_OK)
            goto marshal_error;

        // IAudioCaptureClient
        hResult = CoMarshalInterThreadInterfaceInStream(&pa_IID_IAudioCaptureClient, (LPUNKNOWN)stream->captureClientParent, &stream->captureClientStream);
        if (hResult != S_OK)
            goto marshal_error;
    }

    if (NULL != stream->out.clientParent)
    {
        // SubStream pointers
        hResult = MarshalSubStreamComPointers(&stream->out);
        if (hResult != S_OK)
            goto marshal_error;

        // IAudioRenderClient
        hResult = CoMarshalInterThreadInterfaceInStream(&pa_IID_IAudioRenderClient, (LPUNKNOWN)stream->renderClientParent, &stream->renderClientStream);
        if (hResult != S_OK)
            goto marshal_error;
    }

    return hResult;

    // If marshaling error occurred, make sure to release everything.
marshal_error:

    UnmarshalStreamComPointers(stream);
    ReleaseUnmarshaledComPointers(stream);
    return hResult;
#else
    (void)stream;
    return S_OK;
#endif
}

// ------------------------------------------------------------------------------------------
static PaError StartStream( PaStream *s )
{
    HRESULT hr;
    PaWasapiStream *stream = (PaWasapiStream*)s;
    PaError result = paNoError;

    // check if stream is active already
    if (IsStreamActive(s))
        return paStreamIsNotStopped;

    PaUtil_ResetBufferProcessor(&stream->bufferProcessor);

    // Cleanup handles (may be necessary if stream was stopped by itself due to error)
    _StreamCleanup(stream);

    // Create close event
    if ((stream->hCloseRequest = CreateEvent(NULL, TRUE, FALSE, NULL)) == NULL)
    {
        result = paInsufficientMemory;
        goto start_error;
    }

    // Create thread
    if (!stream->bBlocking)
    {
        // Create thread events
        stream->hThreadStart = CreateEvent(NULL, TRUE, FALSE, NULL);
        stream->hThreadExit  = CreateEvent(NULL, TRUE, FALSE, NULL);
        if ((stream->hThreadStart == NULL) || (stream->hThreadExit == NULL))
        {
            result = paInsufficientMemory;
            goto start_error;
        }

        // Marshal WASAPI interface pointers for safe use in thread created below.
        if ((hr = MarshalStreamComPointers(stream)) != S_OK)
        {
            PRINT(("Failed marshaling stream COM pointers."));
            result = paUnanticipatedHostError;
            goto nonblocking_start_error;
        }

        if ((stream->in.clientParent  && (stream->in.streamFlags  & AUDCLNT_STREAMFLAGS_EVENTCALLBACK)) ||
            (stream->out.clientParent && (stream->out.streamFlags & AUDCLNT_STREAMFLAGS_EVENTCALLBACK)))
        {
            if ((stream->hThread = CREATE_THREAD(ProcThreadEvent)) == NULL)
            {
                PRINT(("Failed creating thread: ProcThreadEvent."));
                result = paUnanticipatedHostError;
                goto nonblocking_start_error;
            }
        }
        else
        {
            if ((stream->hThread = CREATE_THREAD(ProcThreadPoll)) == NULL)
            {
                PRINT(("Failed creating thread: ProcThreadPoll."));
                result = paUnanticipatedHostError;
                goto nonblocking_start_error;
            }
        }

        // Wait for thread to start
        if (WaitForSingleObject(stream->hThreadStart, 60*1000) == WAIT_TIMEOUT)
        {
            PRINT(("Failed starting thread: timeout."));
            result = paUnanticipatedHostError;
            goto nonblocking_start_error;
        }
    }
    else
    {
        // Create blocking operation events (non-signaled event means - blocking operation is pending)
        if (stream->out.clientParent != NULL)
        {
            if ((stream->hBlockingOpStreamWR = CreateEvent(NULL, TRUE, TRUE, NULL)) == NULL)
            {
                result = paInsufficientMemory;
                goto start_error;
            }
        }
        if (stream->in.clientParent != NULL)
        {
            if ((stream->hBlockingOpStreamRD = CreateEvent(NULL, TRUE, TRUE, NULL)) == NULL)
            {
                result = paInsufficientMemory;
                goto start_error;
            }
        }

        // Initialize event & start INPUT stream
        if (stream->in.clientParent != NULL)
        {
            if ((hr = IAudioClient_Start(stream->in.clientParent)) != S_OK)
            {
                LogHostError(hr);
                result = paUnanticipatedHostError;
                goto start_error;
            }
        }

        // Initialize event & start OUTPUT stream
        if (stream->out.clientParent != NULL)
        {
            // Start
            if ((hr = IAudioClient_Start(stream->out.clientParent)) != S_OK)
            {
                LogHostError(hr);
                result = paUnanticipatedHostError;
                goto start_error;
            }
        }

        // Set parent to working pointers to use shared functions.
        stream->captureClient  = stream->captureClientParent;
        stream->renderClient   = stream->renderClientParent;
        stream->in.clientProc  = stream->in.clientParent;
        stream->out.clientProc = stream->out.clientParent;

        // Signal: stream running.
        stream->running = TRUE;
    }

    return result;

nonblocking_start_error:

    // Set hThreadExit event to prevent blocking during cleanup
    SetEvent(stream->hThreadExit);
    UnmarshalStreamComPointers(stream);
    ReleaseUnmarshaledComPointers(stream);

start_error:

    StopStream(s);
    return result;
}

// ------------------------------------------------------------------------------------------
void _StreamFinish(PaWasapiStream *stream)
{
    // Issue command to thread to stop processing and wait for thread exit
    if (!stream->bBlocking)
    {
        SignalObjectAndWait(stream->hCloseRequest, stream->hThreadExit, INFINITE, FALSE);
    }
    else
    // Blocking mode does not own thread
    {
        // Signal close event and wait for each of 2 blocking operations to complete
        if (stream->out.clientParent)
            SignalObjectAndWait(stream->hCloseRequest, stream->hBlockingOpStreamWR, INFINITE, TRUE);
        if (stream->out.clientParent)
            SignalObjectAndWait(stream->hCloseRequest, stream->hBlockingOpStreamRD, INFINITE, TRUE);

        // Process stop
        _StreamOnStop(stream);
    }

    // Cleanup handles
    _StreamCleanup(stream);

    stream->running = FALSE;
}

// ------------------------------------------------------------------------------------------
void _StreamCleanup(PaWasapiStream *stream)
{
    // Close thread handles to allow restart
    SAFE_CLOSE(stream->hThread);
    SAFE_CLOSE(stream->hThreadStart);
    SAFE_CLOSE(stream->hThreadExit);
    SAFE_CLOSE(stream->hCloseRequest);
    SAFE_CLOSE(stream->hBlockingOpStreamRD);
    SAFE_CLOSE(stream->hBlockingOpStreamWR);
}

// ------------------------------------------------------------------------------------------
static PaError StopStream( PaStream *s )
{
    // Finish stream
    _StreamFinish((PaWasapiStream *)s);
    return paNoError;
}

// ------------------------------------------------------------------------------------------
static PaError AbortStream( PaStream *s )
{
    // Finish stream
    _StreamFinish((PaWasapiStream *)s);
    return paNoError;
}

// ------------------------------------------------------------------------------------------
static PaError IsStreamStopped( PaStream *s )
{
    return !((PaWasapiStream *)s)->running;
}

// ------------------------------------------------------------------------------------------
static PaError IsStreamActive( PaStream *s )
{
    return ((PaWasapiStream *)s)->running;
}

// ------------------------------------------------------------------------------------------
static PaTime GetStreamTime( PaStream *s )
{
    PaWasapiStream *stream = (PaWasapiStream*)s;

    /* suppress unused variable warnings */
    (void) stream;

    return PaUtil_GetTime();
}

// ------------------------------------------------------------------------------------------
static double GetStreamCpuLoad( PaStream* s )
{
    return PaUtil_GetCpuLoad(&((PaWasapiStream *)s)->cpuLoadMeasurer);
}

// ------------------------------------------------------------------------------------------
static PaError ReadStream( PaStream* s, void *_buffer, unsigned long frames )
{
    PaWasapiStream *stream = (PaWasapiStream*)s;

    HRESULT hr = S_OK;
    BYTE *user_buffer = (BYTE *)_buffer;
    BYTE *wasapi_buffer = NULL;
    DWORD flags = 0;
    UINT32 i, available, sleep = 0;
    unsigned long processed;
    ThreadIdleScheduler sched;

    // validate
    if (!stream->running)
        return paStreamIsStopped;
    if (stream->captureClient == NULL)
        return paBadStreamPtr;

    // Notify blocking op has begun
    ResetEvent(stream->hBlockingOpStreamRD);

    // Use thread scheduling for 500 microseconds (emulated) when wait time for frames is less than
    // 1 milliseconds, emulation helps to normalize CPU consumption and avoids too busy waiting
    ThreadIdleScheduler_Setup(&sched, 1, 250/* microseconds */);

    // Make a local copy of the user buffer pointer(s), this is necessary
    // because PaUtil_CopyOutput() advances these pointers every time it is called
    if (!stream->bufferProcessor.userInputIsInterleaved)
    {
        user_buffer = (BYTE *)alloca(sizeof(BYTE *) * stream->bufferProcessor.inputChannelCount);
        if (user_buffer == NULL)
            return paInsufficientMemory;

        for (i = 0; i < stream->bufferProcessor.inputChannelCount; ++i)
            ((BYTE **)user_buffer)[i] = ((BYTE **)_buffer)[i];
    }

    // Find out if there are tail frames, flush them all before reading hardware
    if ((available = PaUtil_GetRingBufferReadAvailable(stream->in.tailBuffer)) != 0)
    {
        ring_buffer_size_t buf1_size = 0, buf2_size = 0, read, desired;
        void *buf1 = NULL, *buf2 = NULL;

        // Limit desired to amount of requested frames
        desired = available;
        if ((UINT32)desired > frames)
            desired = frames;

        // Get pointers to read regions
        read = PaUtil_GetRingBufferReadRegions(stream->in.tailBuffer, desired, &buf1, &buf1_size, &buf2, &buf2_size);

        if (buf1 != NULL)
        {
            // Register available frames to processor
            PaUtil_SetInputFrameCount(&stream->bufferProcessor, buf1_size);

            // Register host buffer pointer to processor
            PaUtil_SetInterleavedInputChannels(&stream->bufferProcessor, 0, buf1, stream->bufferProcessor.inputChannelCount);

            // Copy user data to host buffer (with conversion if applicable)
            processed = PaUtil_CopyInput(&stream->bufferProcessor, (void **)&user_buffer, buf1_size);
            frames -= processed;
        }

        if (buf2 != NULL)
        {
            // Register available frames to processor
            PaUtil_SetInputFrameCount(&stream->bufferProcessor, buf2_size);

            // Register host buffer pointer to processor
            PaUtil_SetInterleavedInputChannels(&stream->bufferProcessor, 0, buf2, stream->bufferProcessor.inputChannelCount);

            // Copy user data to host buffer (with conversion if applicable)
            processed = PaUtil_CopyInput(&stream->bufferProcessor, (void **)&user_buffer, buf2_size);
            frames -= processed;
        }

        // Advance
        PaUtil_AdvanceRingBufferReadIndex(stream->in.tailBuffer, read);
    }

    // Read hardware
    while (frames != 0)
    {
        // Check if blocking call must be interrupted
        if (WaitForSingleObject(stream->hCloseRequest, sleep) != WAIT_TIMEOUT)
            break;

        // Get available frames (must be finding out available frames before call to IAudioCaptureClient_GetBuffer
        // othervise audio glitches will occur inExclusive mode as it seems that WASAPI has some scheduling/
        // processing problems when such busy polling with IAudioCaptureClient_GetBuffer occurs)
        if ((hr = _PollGetInputFramesAvailable(stream, &available)) != S_OK)
        {
            LogHostError(hr);
            return paUnanticipatedHostError;
        }

        // Wait for more frames to become available
        if (available == 0)
        {
            // Exclusive mode may require latency of 1 millisecond, thus we shall sleep
            // around 500 microseconds (emulated) to collect packets in time
            if (stream->in.shareMode != AUDCLNT_SHAREMODE_EXCLUSIVE)
            {
                UINT32 sleep_frames = (frames < stream->in.framesPerHostCallback ? frames : stream->in.framesPerHostCallback);

                sleep  = GetFramesSleepTime(sleep_frames, stream->in.wavex.Format.nSamplesPerSec);
                sleep /= 4; // wait only for 1/4 of the buffer

                // WASAPI input provides packets, thus expiring packet will result in bad audio
                // limit waiting time to 2 seconds (will always work for smallest buffer in Shared)
                if (sleep > 2)
                    sleep = 2;

                // Avoid busy waiting, schedule next 1 millesecond wait
                if (sleep == 0)
                    sleep = ThreadIdleScheduler_NextSleep(&sched);
            }
            else
            {
                if ((sleep = ThreadIdleScheduler_NextSleep(&sched)) != 0)
                {
                    Sleep(sleep);
                    sleep = 0;
                }
            }

            continue;
        }

        // Get the available data in the shared buffer.
        if ((hr = IAudioCaptureClient_GetBuffer(stream->captureClient, &wasapi_buffer, &available, &flags, NULL, NULL)) != S_OK)
        {
            // Buffer size is too small, waiting
            if (hr != AUDCLNT_S_BUFFER_EMPTY)
            {
                LogHostError(hr);
                goto end;
            }

            continue;
        }

        // Register available frames to processor
        PaUtil_SetInputFrameCount(&stream->bufferProcessor, available);

        // Register host buffer pointer to processor
        PaUtil_SetInterleavedInputChannels(&stream->bufferProcessor, 0, wasapi_buffer, stream->bufferProcessor.inputChannelCount);

        // Copy user data to host buffer (with conversion if applicable)
        processed = PaUtil_CopyInput(&stream->bufferProcessor, (void **)&user_buffer, frames);
        frames -= processed;

        // Save tail into buffer
        if ((frames == 0) && (available > processed))
        {
            UINT32 bytes_processed = processed * stream->in.wavex.Format.nBlockAlign;
            UINT32 frames_to_save  = available - processed;

            PaUtil_WriteRingBuffer(stream->in.tailBuffer, wasapi_buffer + bytes_processed, frames_to_save);
        }

        // Release host buffer
        if ((hr = IAudioCaptureClient_ReleaseBuffer(stream->captureClient, available)) != S_OK)
        {
            LogHostError(hr);
            goto end;
        }
    }

end:

    // Notify blocking op has ended
    SetEvent(stream->hBlockingOpStreamRD);

    return (hr != S_OK ? paUnanticipatedHostError : paNoError);
}

// ------------------------------------------------------------------------------------------
static PaError WriteStream( PaStream* s, const void *_buffer, unsigned long frames )
{
    PaWasapiStream *stream = (PaWasapiStream*)s;

    //UINT32 frames;
    const BYTE *user_buffer = (const BYTE *)_buffer;
    BYTE *wasapi_buffer;
    HRESULT hr = S_OK;
    UINT32 i, available, sleep = 0;
    unsigned long processed;
    ThreadIdleScheduler sched;

    // validate
    if (!stream->running)
        return paStreamIsStopped;
    if (stream->renderClient == NULL)
        return paBadStreamPtr;

    // Notify blocking op has begun
    ResetEvent(stream->hBlockingOpStreamWR);

    // Use thread scheduling for 500 microseconds (emulated) when wait time for frames is less than
    // 1 milliseconds, emulation helps to normalize CPU consumption and avoids too busy waiting
    ThreadIdleScheduler_Setup(&sched, 1, 500/* microseconds */);

    // Make a local copy of the user buffer pointer(s), this is necessary
    // because PaUtil_CopyOutput() advances these pointers every time it is called
    if (!stream->bufferProcessor.userOutputIsInterleaved)
    {
        user_buffer = (const BYTE *)alloca(sizeof(const BYTE *) * stream->bufferProcessor.outputChannelCount);
        if (user_buffer == NULL)
            return paInsufficientMemory;

        for (i = 0; i < stream->bufferProcessor.outputChannelCount; ++i)
            ((const BYTE **)user_buffer)[i] = ((const BYTE **)_buffer)[i];
    }

    // Blocking (potentially, until 'frames' are consumed) loop
    while (frames != 0)
    {
        // Check if blocking call must be interrupted
        if (WaitForSingleObject(stream->hCloseRequest, sleep) != WAIT_TIMEOUT)
            break;

        // Get frames available
        if ((hr = _PollGetOutputFramesAvailable(stream, &available)) != S_OK)
        {
            LogHostError(hr);
            goto end;
        }

        // Wait for more frames to become available
        if (available == 0)
        {
            UINT32 sleep_frames = (frames < stream->out.framesPerHostCallback ? frames : stream->out.framesPerHostCallback);

            sleep  = GetFramesSleepTime(sleep_frames, stream->out.wavex.Format.nSamplesPerSec);
            sleep /= 2; // wait only for half of the buffer

            // Avoid busy waiting, schedule next 1 millesecond wait
            if (sleep == 0)
                sleep = ThreadIdleScheduler_NextSleep(&sched);

            continue;
        }

        // Keep in 'frames' range
        if (available > frames)
            available = frames;

        // Get pointer to host buffer
        if ((hr = IAudioRenderClient_GetBuffer(stream->renderClient, available, &wasapi_buffer)) != S_OK)
        {
            // Buffer size is too big, waiting
            if (hr == AUDCLNT_E_BUFFER_TOO_LARGE)
                continue;

            LogHostError(hr);
            goto end;
        }

        // Keep waiting again (on Vista it was noticed that WASAPI could SOMETIMES return NULL pointer
        // to buffer without returning AUDCLNT_E_BUFFER_TOO_LARGE instead)
        if (wasapi_buffer == NULL)
            continue;

        // Register available frames to processor
        PaUtil_SetOutputFrameCount(&stream->bufferProcessor, available);

        // Register host buffer pointer to processor
        PaUtil_SetInterleavedOutputChannels(&stream->bufferProcessor, 0, wasapi_buffer,    stream->bufferProcessor.outputChannelCount);

        // Copy user data to host buffer (with conversion if applicable), this call will advance
        // pointer 'user_buffer' to consumed portion of data
        processed = PaUtil_CopyOutput(&stream->bufferProcessor, (const void **)&user_buffer, frames);
        frames -= processed;

        // Release host buffer
        if ((hr = IAudioRenderClient_ReleaseBuffer(stream->renderClient, available, 0)) != S_OK)
        {
            LogHostError(hr);
            goto end;
        }
    }

end:

    // Notify blocking op has ended
    SetEvent(stream->hBlockingOpStreamWR);

    return (hr != S_OK ? paUnanticipatedHostError : paNoError);
}

unsigned long PaUtil_GetOutputFrameCount( PaUtilBufferProcessor* bp )
{
    return bp->hostOutputFrameCount[0];
}

// ------------------------------------------------------------------------------------------
static signed long GetStreamReadAvailable( PaStream* s )
{
    PaWasapiStream *stream = (PaWasapiStream*)s;

    HRESULT hr;
    UINT32  available = 0;

    // validate
    if (!stream->running)
        return paStreamIsStopped;
    if (stream->captureClient == NULL)
        return paBadStreamPtr;

    // available in hardware buffer
    if ((hr = _PollGetInputFramesAvailable(stream, &available)) != S_OK)
    {
        LogHostError(hr);
        return paUnanticipatedHostError;
    }

    // available in software tail buffer
    available += PaUtil_GetRingBufferReadAvailable(stream->in.tailBuffer);

    return available;
}

// ------------------------------------------------------------------------------------------
static signed long GetStreamWriteAvailable( PaStream* s )
{
    PaWasapiStream *stream = (PaWasapiStream*)s;
    HRESULT hr;
    UINT32  available = 0;

    // validate
    if (!stream->running)
        return paStreamIsStopped;
    if (stream->renderClient == NULL)
        return paBadStreamPtr;

    if ((hr = _PollGetOutputFramesAvailable(stream, &available)) != S_OK)
    {
        LogHostError(hr);
        return paUnanticipatedHostError;
    }

    return (signed long)available;
}


// ------------------------------------------------------------------------------------------
static void WaspiHostProcessingLoop( void *inputBuffer,  long inputFrames,
                                     void *outputBuffer, long outputFrames,
                                     void *userData )
{
    PaWasapiStream *stream = (PaWasapiStream*)userData;
    PaStreamCallbackTimeInfo timeInfo = {0,0,0};
    PaStreamCallbackFlags flags = 0;
    int callbackResult;
    unsigned long framesProcessed;
    HRESULT hr;
    UINT32 pending;

    PaUtil_BeginCpuLoadMeasurement( &stream->cpuLoadMeasurer );

    /*
        Pa_GetStreamTime:
            - generate timing information
            - handle buffer slips
    */
    timeInfo.currentTime = PaUtil_GetTime();
    // Query input latency
    if (stream->in.clientProc != NULL)
    {
        PaTime pending_time;
        if ((hr = IAudioClient_GetCurrentPadding(stream->in.clientProc, &pending)) == S_OK)
            pending_time = (PaTime)pending / (PaTime)stream->in.wavex.Format.nSamplesPerSec;
        else
            pending_time = (PaTime)stream->in.latencySeconds;

        timeInfo.inputBufferAdcTime = timeInfo.currentTime + pending_time;
    }
    // Query output current latency
    if (stream->out.clientProc != NULL)
    {
        PaTime pending_time;
        if ((hr = IAudioClient_GetCurrentPadding(stream->out.clientProc, &pending)) == S_OK)
            pending_time = (PaTime)pending / (PaTime)stream->out.wavex.Format.nSamplesPerSec;
        else
            pending_time = (PaTime)stream->out.latencySeconds;

        timeInfo.outputBufferDacTime = timeInfo.currentTime + pending_time;
    }

    /*
        If you need to byte swap or shift inputBuffer to convert it into a
        portaudio format, do it here.
    */

    PaUtil_BeginBufferProcessing( &stream->bufferProcessor, &timeInfo, flags );

    /*
        depending on whether the host buffers are interleaved, non-interleaved
        or a mixture, you will want to call PaUtil_SetInterleaved*Channels(),
        PaUtil_SetNonInterleaved*Channel() or PaUtil_Set*Channel() here.
    */

    if (stream->bufferProcessor.inputChannelCount > 0)
    {
        PaUtil_SetInputFrameCount( &stream->bufferProcessor, inputFrames );
        PaUtil_SetInterleavedInputChannels( &stream->bufferProcessor,
            0, /* first channel of inputBuffer is channel 0 */
            inputBuffer,
            0 ); /* 0 - use inputChannelCount passed to init buffer processor */
    }

    if (stream->bufferProcessor.outputChannelCount > 0)
    {
        PaUtil_SetOutputFrameCount( &stream->bufferProcessor, outputFrames);
        PaUtil_SetInterleavedOutputChannels( &stream->bufferProcessor,
            0, /* first channel of outputBuffer is channel 0 */
            outputBuffer,
            0 ); /* 0 - use outputChannelCount passed to init buffer processor */
    }

    /* you must pass a valid value of callback result to PaUtil_EndBufferProcessing()
        in general you would pass paContinue for normal operation, and
        paComplete to drain the buffer processor's internal output buffer.
        You can check whether the buffer processor's output buffer is empty
        using PaUtil_IsBufferProcessorOuputEmpty( bufferProcessor )
    */
    callbackResult = paContinue;
    framesProcessed = PaUtil_EndBufferProcessing( &stream->bufferProcessor, &callbackResult );

    /*
        If you need to byte swap or shift outputBuffer to convert it to
        host format, do it here.
    */

    PaUtil_EndCpuLoadMeasurement( &stream->cpuLoadMeasurer, framesProcessed );

    if (callbackResult == paContinue)
    {
        /* nothing special to do */
    }
    else
    if (callbackResult == paAbort)
    {
        // stop stream
        SetEvent(stream->hCloseRequest);
    }
    else
    {
        // stop stream
        SetEvent(stream->hCloseRequest);
    }
}

// ------------------------------------------------------------------------------------------
#ifndef PA_WINRT
static PaError MMCSS_activate(PaWasapiThreadPriority nPriorityClass, HANDLE *ret)
{
    static const char *mmcs_name[] =
    {
        NULL,
        "Audio",
        "Capture",
        "Distribution",
        "Games",
        "Playback",
        "Pro Audio",
        "Window Manager"
    };

    DWORD task_idx = 0;
    HANDLE hTask;

    if ((UINT32)nPriorityClass >= STATIC_ARRAY_SIZE(mmcs_name))
        return paUnanticipatedHostError;

    if ((hTask = pAvSetMmThreadCharacteristics(mmcs_name[nPriorityClass], &task_idx)) == NULL)
    {
        PRINT(("WASAPI: AvSetMmThreadCharacteristics failed: error[%d]\n", GetLastError()));
        return paUnanticipatedHostError;
    }

    /*BOOL priority_ok = pAvSetMmThreadPriority(hTask, AVRT_PRIORITY_NORMAL);
    if (priority_ok == FALSE)
    {
        PRINT(("WASAPI: AvSetMmThreadPriority failed!\n"));
    }*/

    // debug
    {
        int    cur_priority          = GetThreadPriority(GetCurrentThread());
        DWORD  cur_priority_class = GetPriorityClass(GetCurrentProcess());
        PRINT(("WASAPI: thread[ priority-0x%X class-0x%X ]\n", cur_priority, cur_priority_class));
    }

    (*ret) = hTask;
    return paNoError;
}
#endif

// ------------------------------------------------------------------------------------------
#ifndef PA_WINRT
static void MMCSS_deactivate(HANDLE hTask)
{
    if (pAvRevertMmThreadCharacteristics(hTask) == FALSE)
    {
        PRINT(("WASAPI: AvRevertMmThreadCharacteristics failed!\n"));
    }
}
#endif

// ------------------------------------------------------------------------------------------
PaError PaWasapi_ThreadPriorityBoost(void **pTask, PaWasapiThreadPriority priorityClass)
{
    HANDLE task;
    PaError ret;

    if (pTask == NULL)
        return paUnanticipatedHostError;

#ifndef PA_WINRT
    if ((ret = MMCSS_activate(priorityClass, &task)) != paNoError)
        return ret;
#else
    switch (priorityClass)
    {
    case eThreadPriorityAudio:
    case eThreadPriorityProAudio: {

        // Save previous thread priority
        intptr_t priority_prev = GetThreadPriority(GetCurrentThread());

        // Try set new thread priority
        if (SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_HIGHEST) == FALSE)
            return paUnanticipatedHostError;

        // Memorize prev priority (pretend to be non NULL pointer by adding 0x80000000 mask)
        task = (HANDLE)(priority_prev | 0x80000000);

        ret = paNoError;

        break; }

    default:
        return paUnanticipatedHostError;
    }
#endif

    (*pTask) = task;
    return ret;
}

// ------------------------------------------------------------------------------------------
PaError PaWasapi_ThreadPriorityRevert(void *pTask)
{
    if (pTask == NULL)
        return paUnanticipatedHostError;

#ifndef PA_WINRT
    MMCSS_deactivate((HANDLE)pTask);
#else
    // Revert previous priority by removing 0x80000000 mask
    if (SetThreadPriority(GetCurrentThread(), (int)((intptr_t)pTask & ~0x80000000)) == FALSE)
        return paUnanticipatedHostError;
#endif

    return paNoError;
}

// ------------------------------------------------------------------------------------------
// Described at:
// http://msdn.microsoft.com/en-us/library/dd371387(v=VS.85).aspx

PaError PaWasapi_GetJackCount(PaDeviceIndex device, int *pJackCount)
{
#ifndef PA_WINRT
    PaError ret;
    HRESULT hr = S_OK;
    PaWasapiDeviceInfo *deviceInfo;
    IDeviceTopology *pDeviceTopology = NULL;
    IConnector *pConnFrom = NULL;
    IConnector *pConnTo = NULL;
    IPart *pPart = NULL;
    IKsJackDescription *pJackDesc = NULL;
    UINT jackCount = 0;

    if (pJackCount == NULL)
        return paUnanticipatedHostError;

    if ((ret = _GetWasapiDeviceInfoByDeviceIndex(&deviceInfo, device)) != paNoError)
        return ret;

    // Get the endpoint device's IDeviceTopology interface
    hr = IMMDevice_Activate(deviceInfo->device, &pa_IID_IDeviceTopology,
        CLSCTX_INPROC_SERVER, NULL, (void**)&pDeviceTopology);
    IF_FAILED_JUMP(hr, error);

    // The device topology for an endpoint device always contains just one connector (connector number 0)
    hr = IDeviceTopology_GetConnector(pDeviceTopology, 0, &pConnFrom);
    IF_FAILED_JUMP(hr, error);

    // Step across the connection to the jack on the adapter
    hr = IConnector_GetConnectedTo(pConnFrom, &pConnTo);
    if (HRESULT_FROM_WIN32(ERROR_PATH_NOT_FOUND) == hr)
    {
        // The adapter device is not currently active
        hr = E_NOINTERFACE;
    }
    IF_FAILED_JUMP(hr, error);

    // Get the connector's IPart interface
    hr = IConnector_QueryInterface(pConnTo, &pa_IID_IPart, (void**)&pPart);
    IF_FAILED_JUMP(hr, error);

    // Activate the connector's IKsJackDescription interface
    hr = IPart_Activate(pPart, CLSCTX_INPROC_SERVER, &pa_IID_IKsJackDescription, (void**)&pJackDesc);
    IF_FAILED_JUMP(hr, error);

    // Return jack count for this device
    hr = IKsJackDescription_GetJackCount(pJackDesc, &jackCount);
    IF_FAILED_JUMP(hr, error);

    // Set.
    (*pJackCount) = jackCount;

    // Ok.
    ret = paNoError;

error:

    SAFE_RELEASE(pDeviceTopology);
    SAFE_RELEASE(pConnFrom);
    SAFE_RELEASE(pConnTo);
    SAFE_RELEASE(pPart);
    SAFE_RELEASE(pJackDesc);

    LogHostError(hr);
    return paNoError;
#else
    (void)device;
    (void)pJackCount;
    return paUnanticipatedHostError;
#endif
}

// ------------------------------------------------------------------------------------------
#ifndef PA_WINRT
static PaWasapiJackConnectionType _ConvertJackConnectionTypeWASAPIToPA(int connType)
{
    switch (connType)
    {
        case eConnTypeUnknown:               return eJackConnTypeUnknown;
#ifdef _KS_
        case eConnType3Point5mm:             return eJackConnType3Point5mm;
#else
        case eConnTypeEighth:                return eJackConnType3Point5mm;
#endif
        case eConnTypeQuarter:               return eJackConnTypeQuarter;
        case eConnTypeAtapiInternal:         return eJackConnTypeAtapiInternal;
        case eConnTypeRCA:                   return eJackConnTypeRCA;
        case eConnTypeOptical:               return eJackConnTypeOptical;
        case eConnTypeOtherDigital:          return eJackConnTypeOtherDigital;
        case eConnTypeOtherAnalog:           return eJackConnTypeOtherAnalog;
        case eConnTypeMultichannelAnalogDIN: return eJackConnTypeMultichannelAnalogDIN;
        case eConnTypeXlrProfessional:       return eJackConnTypeXlrProfessional;
        case eConnTypeRJ11Modem:             return eJackConnTypeRJ11Modem;
        case eConnTypeCombination:           return eJackConnTypeCombination;
    }
    return eJackConnTypeUnknown;
}
#endif

// ------------------------------------------------------------------------------------------
#ifndef PA_WINRT
static PaWasapiJackGeoLocation _ConvertJackGeoLocationWASAPIToPA(int geoLoc)
{
    switch (geoLoc)
    {
    case eGeoLocRear:             return eJackGeoLocRear;
    case eGeoLocFront:            return eJackGeoLocFront;
    case eGeoLocLeft:             return eJackGeoLocLeft;
    case eGeoLocRight:            return eJackGeoLocRight;
    case eGeoLocTop:              return eJackGeoLocTop;
    case eGeoLocBottom:           return eJackGeoLocBottom;
#ifdef _KS_
    case eGeoLocRearPanel:        return eJackGeoLocRearPanel;
#else
    case eGeoLocRearOPanel:       return eJackGeoLocRearPanel;
#endif
    case eGeoLocRiser:            return eJackGeoLocRiser;
    case eGeoLocInsideMobileLid:  return eJackGeoLocInsideMobileLid;
    case eGeoLocDrivebay:         return eJackGeoLocDrivebay;
    case eGeoLocHDMI:             return eJackGeoLocHDMI;
    case eGeoLocOutsideMobileLid: return eJackGeoLocOutsideMobileLid;
    case eGeoLocATAPI:            return eJackGeoLocATAPI;
    }
    return eJackGeoLocUnk;
}
#endif

// ------------------------------------------------------------------------------------------
#ifndef PA_WINRT
static PaWasapiJackGenLocation _ConvertJackGenLocationWASAPIToPA(int genLoc)
{
    switch (genLoc)
    {
    case eGenLocPrimaryBox: return eJackGenLocPrimaryBox;
    case eGenLocInternal:   return eJackGenLocInternal;
#ifdef _KS_
    case eGenLocSeparate:   return eJackGenLocSeparate;
#else
    case eGenLocSeperate:   return eJackGenLocSeparate;
#endif
    case eGenLocOther:      return eJackGenLocOther;
    }
    return eJackGenLocPrimaryBox;
}
#endif

// ------------------------------------------------------------------------------------------
#ifndef PA_WINRT
static PaWasapiJackPortConnection _ConvertJackPortConnectionWASAPIToPA(int portConn)
{
    switch (portConn)
    {
    case ePortConnJack:                  return eJackPortConnJack;
    case ePortConnIntegratedDevice:      return eJackPortConnIntegratedDevice;
    case ePortConnBothIntegratedAndJack: return eJackPortConnBothIntegratedAndJack;
    case ePortConnUnknown:               return eJackPortConnUnknown;
    }
    return eJackPortConnJack;
}
#endif

// ------------------------------------------------------------------------------------------
// Described at:
// http://msdn.microsoft.com/en-us/library/dd371387(v=VS.85).aspx

PaError PaWasapi_GetJackDescription(PaDeviceIndex device, int jackIndex, PaWasapiJackDescription *pJackDescription)
{
#ifndef PA_WINRT
    PaError ret;
    HRESULT hr = S_OK;
    PaWasapiDeviceInfo *deviceInfo;
    IDeviceTopology *pDeviceTopology = NULL;
    IConnector *pConnFrom = NULL;
    IConnector *pConnTo = NULL;
    IPart *pPart = NULL;
    IKsJackDescription *pJackDesc = NULL;
    KSJACK_DESCRIPTION jack = { 0 };

    if ((ret = _GetWasapiDeviceInfoByDeviceIndex(&deviceInfo, device)) != paNoError)
        return ret;

    // Get the endpoint device's IDeviceTopology interface
    hr = IMMDevice_Activate(deviceInfo->device, &pa_IID_IDeviceTopology,
        CLSCTX_INPROC_SERVER, NULL, (void**)&pDeviceTopology);
    IF_FAILED_JUMP(hr, error);

    // The device topology for an endpoint device always contains just one connector (connector number 0)
    hr = IDeviceTopology_GetConnector(pDeviceTopology, 0, &pConnFrom);
    IF_FAILED_JUMP(hr, error);

    // Step across the connection to the jack on the adapter
    hr = IConnector_GetConnectedTo(pConnFrom, &pConnTo);
    if (HRESULT_FROM_WIN32(ERROR_PATH_NOT_FOUND) == hr)
    {
        // The adapter device is not currently active
        hr = E_NOINTERFACE;
    }
    IF_FAILED_JUMP(hr, error);

    // Get the connector's IPart interface
    hr = IConnector_QueryInterface(pConnTo, &pa_IID_IPart, (void**)&pPart);
    IF_FAILED_JUMP(hr, error);

    // Activate the connector's IKsJackDescription interface
    hr = IPart_Activate(pPart, CLSCTX_INPROC_SERVER, &pa_IID_IKsJackDescription, (void**)&pJackDesc);
    IF_FAILED_JUMP(hr, error);

    // Test to return jack description struct for index 0
    hr = IKsJackDescription_GetJackDescription(pJackDesc, jackIndex, &jack);
    IF_FAILED_JUMP(hr, error);

    // Convert WASAPI values to PA format
    pJackDescription->channelMapping = jack.ChannelMapping;
    pJackDescription->color          = jack.Color;
    pJackDescription->connectionType = _ConvertJackConnectionTypeWASAPIToPA(jack.ConnectionType);
    pJackDescription->genLocation    = _ConvertJackGenLocationWASAPIToPA(jack.GenLocation);
    pJackDescription->geoLocation    = _ConvertJackGeoLocationWASAPIToPA(jack.GeoLocation);
    pJackDescription->isConnected    = jack.IsConnected;
    pJackDescription->portConnection = _ConvertJackPortConnectionWASAPIToPA(jack.PortConnection);

    // Ok
    ret = paNoError;

error:

    SAFE_RELEASE(pDeviceTopology);
    SAFE_RELEASE(pConnFrom);
    SAFE_RELEASE(pConnTo);
    SAFE_RELEASE(pPart);
    SAFE_RELEASE(pJackDesc);

    LogHostError(hr);
    return ret;

#else
    (void)device;
    (void)jackIndex;
    (void)pJackDescription;
    return paUnanticipatedHostError;
#endif
}

// ------------------------------------------------------------------------------------------
PaError PaWasapi_GetAudioClient(PaStream *pStream, void **pAudioClient, int bOutput)
{
    PaWasapiStream *stream = (PaWasapiStream *)pStream;
    if (stream == NULL)
        return paBadStreamPtr;

    if (pAudioClient == NULL)
        return paUnanticipatedHostError;

    (*pAudioClient) = (bOutput == TRUE ? stream->out.clientParent : stream->in.clientParent);

    return paNoError;
}

// ------------------------------------------------------------------------------------------
#ifdef PA_WINRT
static void CopyNameOrIdString(WCHAR *dst, const UINT32 dstMaxCount, const WCHAR *src)
{
    UINT32 i;

    for (i = 0; i < dstMaxCount; ++i)
        dst[i] = 0;

    if (src != NULL)
    {
        for (i = 0; (src[i] != 0) && (i < dstMaxCount); ++i)
            dst[i] = src[i];
    }
}
#endif

// ------------------------------------------------------------------------------------------
PaError PaWasapiWinrt_SetDefaultDeviceId( const unsigned short *pId, int bOutput )
{
#ifdef PA_WINRT
    INT32 i;
    PaWasapiWinrtDeviceListRole *role = (bOutput ? &g_DeviceListInfo.render : &g_DeviceListInfo.capture);

    assert(STATIC_ARRAY_SIZE(role->defaultId) == PA_WASAPI_DEVICE_ID_LEN);

    // Validate Id length
    if (pId != NULL)
    {
        for (i = 0; pId[i] != 0; ++i)
        {
            if (i >= PA_WASAPI_DEVICE_ID_LEN)
                return paBufferTooBig;
        }
    }

    // Set Id (or reset to all 0 if NULL is provided)
    CopyNameOrIdString(role->defaultId, STATIC_ARRAY_SIZE(role->defaultId), pId);

    return paNoError;
#else
    return paIncompatibleStreamHostApi;
#endif
}

// ------------------------------------------------------------------------------------------
PaError PaWasapiWinrt_PopulateDeviceList( const unsigned short **pId, const unsigned short **pName,
    const PaWasapiDeviceRole *pRole, unsigned int count, int bOutput )
{
#ifdef PA_WINRT
    UINT32 i, j;
    PaWasapiWinrtDeviceListRole *role = (bOutput ? &g_DeviceListInfo.render : &g_DeviceListInfo.capture);

    memset(&role->devices, 0, sizeof(role->devices));
    role->deviceCount = 0;

    if (count == 0)
        return paNoError;
    else
    if (count > PA_WASAPI_DEVICE_MAX_COUNT)
        return paBufferTooBig;

    // pName or pRole are optional
    if (pId == NULL)
        return paInsufficientMemory;

    // Validate Id and Name lengths
    for (i = 0; i < count; ++i)
    {
        const unsigned short *id = pId[i];
        const unsigned short *name = pName[i];

        for (j = 0; id[j] != 0; ++j)
        {
            if (j >= PA_WASAPI_DEVICE_ID_LEN)
                return paBufferTooBig;
        }

        for (j = 0; name[j] != 0; ++j)
        {
            if (j >= PA_WASAPI_DEVICE_NAME_LEN)
                return paBufferTooBig;
        }
    }

    // Set Id and Name (or reset to all 0 if NULL is provided)
    for (i = 0; i < count; ++i)
    {
        CopyNameOrIdString(role->devices[i].id, STATIC_ARRAY_SIZE(role->devices[i].id), pId[i]);
        CopyNameOrIdString(role->devices[i].name, STATIC_ARRAY_SIZE(role->devices[i].name), pName[i]);
        role->devices[i].formFactor = (pRole != NULL ? (EndpointFormFactor)pRole[i] : UnknownFormFactor);

        // Count device if it has at least the Id
        role->deviceCount += (role->devices[i].id[0] != 0);
    }

    return paNoError;
#else
    return paIncompatibleStreamHostApi;
#endif
}

// ------------------------------------------------------------------------------------------
PaError PaWasapi_SetStreamStateHandler( PaStream *pStream, PaWasapiStreamStateCallback fnStateHandler, void *pUserData )
{
    PaWasapiStream *stream = (PaWasapiStream *)pStream;
    if (stream == NULL)
        return paBadStreamPtr;

    stream->fnStateHandler        = fnStateHandler;
    stream->pStateHandlerUserData = pUserData;

    return paNoError;
}

// ------------------------------------------------------------------------------------------
HRESULT _PollGetOutputFramesAvailable(PaWasapiStream *stream, UINT32 *available)
{
    HRESULT hr;
    UINT32 frames  = stream->out.framesPerHostCallback,
           padding = 0;

    (*available) = 0;

    // get read position
    if ((hr = IAudioClient_GetCurrentPadding(stream->out.clientProc, &padding)) != S_OK)
        return LogHostError(hr);

    // get available
    frames -= padding;

    // set
    (*available) = frames;
    return hr;
}

// ------------------------------------------------------------------------------------------
HRESULT _PollGetInputFramesAvailable(PaWasapiStream *stream, UINT32 *available)
{
    HRESULT hr;

    (*available) = 0;

    // GetCurrentPadding() has opposite meaning to Output stream
    if ((hr = IAudioClient_GetCurrentPadding(stream->in.clientProc, available)) != S_OK)
        return LogHostError(hr);

    return hr;
}

// ------------------------------------------------------------------------------------------
static HRESULT ProcessOutputBuffer(PaWasapiStream *stream, PaWasapiHostProcessor *processor, UINT32 frames)
{
    HRESULT hr;
    BYTE *data = NULL;

    // Get buffer
    if ((hr = IAudioRenderClient_GetBuffer(stream->renderClient, frames, &data)) != S_OK)
    {
        // Both modes, Shared and Exclusive, can fail with AUDCLNT_E_BUFFER_TOO_LARGE error
    #if 0
        if (stream->out.shareMode == AUDCLNT_SHAREMODE_SHARED)
        {
            // Using GetCurrentPadding to overcome AUDCLNT_E_BUFFER_TOO_LARGE in
            // shared mode results in no sound in Event-driven mode (MSDN does not
            // document this, or is it WASAPI bug?), thus we better
            // try to acquire buffer next time when GetBuffer allows to do so.
        #if 0
            // Get Read position
            UINT32 padding = 0;
            hr = IAudioClient_GetCurrentPadding(stream->out.clientProc, &padding);
            if (hr != S_OK)
                return LogHostError(hr);

            // Get frames to write
            frames -= padding;
            if (frames == 0)
                return S_OK;

            if ((hr = IAudioRenderClient_GetBuffer(stream->renderClient, frames, &data)) != S_OK)
                return LogHostError(hr);
        #else
            if (hr == AUDCLNT_E_BUFFER_TOO_LARGE)
                return S_OK; // be silent in shared mode, try again next time
        #endif
        }
        else
            return LogHostError(hr);
    #else
        if (hr == AUDCLNT_E_BUFFER_TOO_LARGE)
            return S_OK; // try again next time

        return LogHostError(hr);
    #endif
    }

    // Process data
    if (stream->out.monoMixer != NULL)
    {
        // expand buffer
        UINT32 mono_frames_size = frames * (stream->out.wavex.Format.wBitsPerSample / 8);
        if (mono_frames_size > stream->out.monoBufferSize)
        {
            stream->out.monoBuffer = PaWasapi_ReallocateMemory(stream->out.monoBuffer, (stream->out.monoBufferSize = mono_frames_size));
            if (stream->out.monoBuffer == NULL)
            {
                hr = E_OUTOFMEMORY;
                LogHostError(hr);
                return hr;
            }
        }

        // process
        processor[S_OUTPUT].processor(NULL, 0, (BYTE *)stream->out.monoBuffer, frames, processor[S_OUTPUT].userData);

        // mix 1 to 2 channels
        stream->out.monoMixer(data, stream->out.monoBuffer, frames);
    }
    else
    {
        processor[S_OUTPUT].processor(NULL, 0, data, frames, processor[S_OUTPUT].userData);
    }

    // Release buffer
    if ((hr = IAudioRenderClient_ReleaseBuffer(stream->renderClient, frames, 0)) != S_OK)
        LogHostError(hr);

    return hr;
}

// ------------------------------------------------------------------------------------------
static HRESULT ProcessInputBuffer(PaWasapiStream *stream, PaWasapiHostProcessor *processor)
{
    HRESULT hr = S_OK;
    UINT32 frames;
    BYTE *data = NULL;
    DWORD flags = 0;

    for (;;)
    {
        // Check if blocking call must be interrupted
        if (WaitForSingleObject(stream->hCloseRequest, 0) != WAIT_TIMEOUT)
            break;

        // Find out if any frames available
        frames = 0;
        if ((hr = _PollGetInputFramesAvailable(stream, &frames)) != S_OK)
            return hr;

        // Empty/consumed buffer
        if (frames == 0)
            break;

        // Get the available data in the shared buffer.
        if ((hr = IAudioCaptureClient_GetBuffer(stream->captureClient, &data, &frames, &flags, NULL, NULL)) != S_OK)
        {
            if (hr == AUDCLNT_S_BUFFER_EMPTY)
            {
                hr = S_OK;
                break; // Empty/consumed buffer
            }

            return LogHostError(hr);
            break;
        }

        // Detect silence
        // if (flags & AUDCLNT_BUFFERFLAGS_SILENT)
        //    data = NULL;

        // Process data
        if (stream->in.monoMixer != NULL)
        {
            // expand buffer
            UINT32 mono_frames_size = frames * (stream->in.wavex.Format.wBitsPerSample / 8);
            if (mono_frames_size > stream->in.monoBufferSize)
            {
                stream->in.monoBuffer = PaWasapi_ReallocateMemory(stream->in.monoBuffer, (stream->in.monoBufferSize = mono_frames_size));
                if (stream->in.monoBuffer == NULL)
                {
                    hr = E_OUTOFMEMORY;
                    LogHostError(hr);
                    return hr;
                }
            }

            // mix 1 to 2 channels
            stream->in.monoMixer(stream->in.monoBuffer, data, frames);

            // process
            processor[S_INPUT].processor((BYTE *)stream->in.monoBuffer, frames, NULL, 0, processor[S_INPUT].userData);
        }
        else
        {
            processor[S_INPUT].processor(data, frames, NULL, 0, processor[S_INPUT].userData);
        }

        // Release buffer
        if ((hr = IAudioCaptureClient_ReleaseBuffer(stream->captureClient, frames)) != S_OK)
            return LogHostError(hr);

        //break;
    }

    return hr;
}

// ------------------------------------------------------------------------------------------
void _StreamOnStop(PaWasapiStream *stream)
{
    // Stop INPUT/OUTPUT clients
    if (!stream->bBlocking)
    {
        if (stream->in.clientProc != NULL)
            IAudioClient_Stop(stream->in.clientProc);
        if (stream->out.clientProc != NULL)
            IAudioClient_Stop(stream->out.clientProc);
    }
    else
    {
        if (stream->in.clientParent != NULL)
            IAudioClient_Stop(stream->in.clientParent);
        if (stream->out.clientParent != NULL)
            IAudioClient_Stop(stream->out.clientParent);
    }

    // Restore thread priority
    if (stream->hAvTask != NULL)
    {
        PaWasapi_ThreadPriorityRevert(stream->hAvTask);
        stream->hAvTask = NULL;
    }

    // Notify
    if (stream->streamRepresentation.streamFinishedCallback != NULL)
        stream->streamRepresentation.streamFinishedCallback(stream->streamRepresentation.userData);
}

// ------------------------------------------------------------------------------------------
static BOOL PrepareComPointers(PaWasapiStream *stream, BOOL *threadComInitialized)
{
    HRESULT hr;

    /*
    If COM is already initialized CoInitialize will either return
    FALSE, or RPC_E_CHANGED_MODE if it was initialized in a different
    threading mode. In either case we shouldn't consider it an error
    but we need to be careful to not call CoUninitialize() if
    RPC_E_CHANGED_MODE was returned.
    */
    hr = CoInitializeEx(NULL, COINIT_APARTMENTTHREADED);
    if (FAILED(hr) && (hr != RPC_E_CHANGED_MODE))
    {
        PRINT(("WASAPI: failed ProcThreadEvent CoInitialize"));
        return FALSE;
    }
    if (hr != RPC_E_CHANGED_MODE)
        *threadComInitialized = TRUE;

    // Unmarshal stream pointers for safe COM operation
    hr = UnmarshalStreamComPointers(stream);
    if (hr != S_OK)
    {
        PRINT(("WASAPI: Error unmarshaling stream COM pointers. HRESULT: %i\n", hr));
        CoUninitialize();
        return FALSE;
    }

    return TRUE;
}

// ------------------------------------------------------------------------------------------
static void FinishComPointers(PaWasapiStream *stream, BOOL threadComInitialized)
{
    // Release unmarshaled COM pointers
    ReleaseUnmarshaledComPointers(stream);

    // Cleanup COM for this thread
    if (threadComInitialized == TRUE)
        CoUninitialize();
}

// ------------------------------------------------------------------------------------------
PA_THREAD_FUNC ProcThreadEvent(void *param)
{
    PaWasapiHostProcessor processor[S_COUNT];
    HRESULT hr = S_OK;
    DWORD dwResult;
    PaWasapiStream *stream = (PaWasapiStream *)param;
    PaWasapiHostProcessor defaultProcessor;
    BOOL setEvent[S_COUNT] = { FALSE, FALSE };
    BOOL waitAllEvents = FALSE;
    BOOL threadComInitialized = FALSE;
    SystemTimer timer;

    // Notify: state
    NotifyStateChanged(stream, paWasapiStreamStateThreadPrepare, ERROR_SUCCESS);

    // Prepare COM pointers
    if (!PrepareComPointers(stream, &threadComInitialized))
        return (UINT32)paUnanticipatedHostError;

    // Request fine (1 ms) granularity of the system timer functions for precise operation of waitable timers
    SystemTimer_SetGranularity(&timer, 1);

    // Waiting on all events in case of Full-Duplex/Exclusive mode.
    if ((stream->in.clientProc != NULL) && (stream->out.clientProc != NULL))
    {
        waitAllEvents = (stream->in.shareMode == AUDCLNT_SHAREMODE_EXCLUSIVE) &&
            (stream->out.shareMode == AUDCLNT_SHAREMODE_EXCLUSIVE);
    }

    // Setup data processors
    defaultProcessor.processor = WaspiHostProcessingLoop;
    defaultProcessor.userData  = stream;
    processor[S_INPUT] = (stream->hostProcessOverrideInput.processor != NULL ? stream->hostProcessOverrideInput : defaultProcessor);
    processor[S_OUTPUT] = (stream->hostProcessOverrideOutput.processor != NULL ? stream->hostProcessOverrideOutput : defaultProcessor);

    // Boost thread priority
    PaWasapi_ThreadPriorityBoost((void **)&stream->hAvTask, stream->nThreadPriority);

    // Create events
    if (stream->event[S_OUTPUT] == NULL)
    {
        stream->event[S_OUTPUT] = CreateEvent(NULL, FALSE, FALSE, NULL);
        setEvent[S_OUTPUT] = TRUE;
    }
    if (stream->event[S_INPUT] == NULL)
    {
        stream->event[S_INPUT]  = CreateEvent(NULL, FALSE, FALSE, NULL);
        setEvent[S_INPUT] = TRUE;
    }
    if ((stream->event[S_OUTPUT] == NULL) || (stream->event[S_INPUT] == NULL))
    {
        PRINT(("WASAPI Thread: failed creating Input/Output event handle\n"));
        goto thread_error;
    }

    // Signal: stream running
    stream->running = TRUE;

    // Notify: thread started
    SetEvent(stream->hThreadStart);

    // Initialize event & start INPUT stream
    if (stream->in.clientProc)
    {
        // Create & set handle
        if (setEvent[S_INPUT])
        {
            if ((hr = IAudioClient_SetEventHandle(stream->in.clientProc, stream->event[S_INPUT])) != S_OK)
            {
                LogHostError(hr);
                goto thread_error;
            }
        }

        // Start
        if ((hr = IAudioClient_Start(stream->in.clientProc)) != S_OK)
        {
            LogHostError(hr);
            goto thread_error;
        }
    }

    // Initialize event & start OUTPUT stream
    if (stream->out.clientProc)
    {
        // Create & set handle
        if (setEvent[S_OUTPUT])
        {
            if ((hr = IAudioClient_SetEventHandle(stream->out.clientProc, stream->event[S_OUTPUT])) != S_OK)
            {
                LogHostError(hr);
                goto thread_error;
            }
        }

        // Preload buffer before start
        if ((hr = ProcessOutputBuffer(stream, processor, stream->out.framesPerBuffer)) != S_OK)
        {
            LogHostError(hr);
            goto thread_error;
        }

        // Start
        if ((hr = IAudioClient_Start(stream->out.clientProc)) != S_OK)
        {
            LogHostError(hr);
            goto thread_error;
        }

    }

    // Notify: state
    NotifyStateChanged(stream, paWasapiStreamStateThreadStart, ERROR_SUCCESS);

    // Processing Loop
    for (;;)
    {
        // 10 sec timeout (on timeout stream will auto-stop when processed by WAIT_TIMEOUT case)
        dwResult = WaitForMultipleObjects(S_COUNT, stream->event, waitAllEvents, 10*1000);

        // Check for close event (after wait for buffers to avoid any calls to user
        // callback when hCloseRequest was set)
        if (WaitForSingleObject(stream->hCloseRequest, 0) != WAIT_TIMEOUT)
            break;

        // Process S_INPUT/S_OUTPUT
        switch (dwResult)
        {
        case WAIT_TIMEOUT: {
            PRINT(("WASAPI Thread: WAIT_TIMEOUT - probably bad audio driver or Vista x64 bug: use paWinWasapiPolling instead\n"));
            goto thread_end;
            break; }

        // Input stream
        case WAIT_OBJECT_0 + S_INPUT: {

            if (stream->captureClient == NULL)
                break;

            if ((hr = ProcessInputBuffer(stream, processor)) != S_OK)
            {
                LogHostError(hr);
                goto thread_error;
            }

            break; }

        // Output stream
        case WAIT_OBJECT_0 + S_OUTPUT: {

            if (stream->renderClient == NULL)
                break;

            if ((hr = ProcessOutputBuffer(stream, processor, stream->out.framesPerBuffer)) != S_OK)
            {
                LogHostError(hr);
                goto thread_error;
            }

            break; }
        }
    }

thread_end:

    // Process stop
    _StreamOnStop(stream);

    // Release unmarshaled COM pointers
    FinishComPointers(stream, threadComInitialized);

    // Restore system timer granularity
    SystemTimer_RestoreGranularity(&timer);

    // Notify: not running
    stream->running = FALSE;

    // Notify: thread exited
    SetEvent(stream->hThreadExit);

    // Notify: state
    NotifyStateChanged(stream, paWasapiStreamStateThreadStop, hr);

    return 0;

thread_error:

    // Prevent deadlocking in Pa_StreamStart
    SetEvent(stream->hThreadStart);

    // Exit
    goto thread_end;
}

// ------------------------------------------------------------------------------------------
static UINT32 GetSleepTime(PaWasapiStream *stream, UINT32 sleepTimeIn, UINT32 sleepTimeOut, UINT32 userFramesOut)
{
    UINT32 sleepTime;

    // According to the issue [https://github.com/PortAudio/portaudio/issues/303] glitches may occur when user frames
    // equal to 1/2 of the host buffer frames, therefore the empirical workaround for this problem is to lower
    // the sleep time by 2
    if (userFramesOut != 0)
    {
        UINT32 chunks = stream->out.framesPerHostCallback / userFramesOut;
        if (chunks <= 2)
        {
            sleepTimeOut /= 2;
            PRINT(("WASAPI: underrun workaround, sleep [%d] ms - 1/2 of the user buffer[%d] | host buffer[%d]\n", sleepTimeOut, userFramesOut, stream->out.framesPerHostCallback));
        }
    }

    // Choose the smallest
    if ((sleepTimeIn != 0) && (sleepTimeOut != 0))
        sleepTime = min(sleepTimeIn, sleepTimeOut);
    else
        sleepTime = (sleepTimeIn ? sleepTimeIn : sleepTimeOut);

    return sleepTime;
}

// ------------------------------------------------------------------------------------------
static UINT32 ConfigureLoopSleepTimeAndScheduler(PaWasapiStream *stream, ThreadIdleScheduler *scheduler)
{
    UINT32 sleepTime, sleepTimeIn, sleepTimeOut;
    UINT32 userFramesIn = stream->in.framesPerHostCallback / WASAPI_PACKETS_PER_INPUT_BUFFER;
    UINT32 userFramesOut = stream->out.framesPerBuffer;

    // Adjust polling time for non-paUtilFixedHostBufferSize, input stream is not adjustable as it is being
    // polled according to its packet length
    if (stream->bufferMode != paUtilFixedHostBufferSize)
    {
        userFramesOut = (stream->bufferProcessor.framesPerUserBuffer ? stream->bufferProcessor.framesPerUserBuffer :
            stream->out.params.frames_per_buffer);
    }

    // Calculate timeout for the next polling attempt
    sleepTimeIn  = GetFramesSleepTime(userFramesIn, stream->in.wavex.Format.nSamplesPerSec);
    sleepTimeOut = GetFramesSleepTime(userFramesOut, stream->out.wavex.Format.nSamplesPerSec);

    // WASAPI input packets tend to expire very easily, let's limit sleep time to 2 milliseconds
    // for all cases. Please propose better solution if any
    if (sleepTimeIn > 2)
        sleepTimeIn = 2;

    sleepTime = GetSleepTime(stream, sleepTimeIn, sleepTimeOut, userFramesOut);

    // Make sure not 0, othervise use ThreadIdleScheduler to bounce between [0, 1] ms to avoid too busy loop
    if (sleepTime == 0)
    {
        sleepTimeIn  = GetFramesSleepTimeMicroseconds(userFramesIn, stream->in.wavex.Format.nSamplesPerSec);
        sleepTimeOut = GetFramesSleepTimeMicroseconds(userFramesOut, stream->out.wavex.Format.nSamplesPerSec);

        sleepTime = GetSleepTime(stream, sleepTimeIn, sleepTimeOut, userFramesOut);

        // Setup thread sleep scheduler
        ThreadIdleScheduler_Setup(scheduler, 1, sleepTime/* microseconds here */);
        sleepTime = 0;
    }

    return sleepTime;
}

// ------------------------------------------------------------------------------------------
static inline INT32 GetNextSleepTime(SystemTimer *timer, ThreadIdleScheduler *scheduler, LONGLONG startTime,
    UINT32 sleepTime)
{
    INT32 nextSleepTime;
    INT32 procTime;

    // Get next sleep time
    if (sleepTime == 0)
        nextSleepTime = ThreadIdleScheduler_NextSleep(scheduler);
    else
        nextSleepTime = sleepTime;

    // Adjust next sleep time dynamically depending on how much time was spent in ProcessOutputBuffer/ProcessInputBuffer
    // therefore periodicity will not jitter or be increased for the amount of time spent in processing;
    // example when sleepTime is 10 ms where [] is polling time slot, {} processing time slot:
    //
    // [9],{2},[8],{1},[9],{1},[9],{3},[7],{2},[8],{3},[7],{2},[8],{2},[8],{3},[7],{2},[8],...
    //
    procTime = (INT32)(SystemTimer_GetTime(timer) - startTime);
    nextSleepTime -= procTime;
    if (nextSleepTime < timer->granularity)
        nextSleepTime = 0;
    else
    if (timer->granularity > 1)
        nextSleepTime = ALIGN_BWD(nextSleepTime, timer->granularity);

#ifdef PA_WASAPI_LOG_TIME_SLOTS
    printf("{%d},", procTime);
#endif

    return nextSleepTime;
}

// ------------------------------------------------------------------------------------------
PA_THREAD_FUNC ProcThreadPoll(void *param)
{
    PaWasapiHostProcessor processor[S_COUNT];
    HRESULT hr = S_OK;
    PaWasapiStream *stream = (PaWasapiStream *)param;
    PaWasapiHostProcessor defaultProcessor;
    INT32 i;
    ThreadIdleScheduler scheduler;
    SystemTimer timer;
    LONGLONG startTime;
    UINT32 sleepTime;
    INT32 nextSleepTime = 0; //! Do first loop without waiting as time could be spent when calling other APIs before ProcessXXXBuffer.
    BOOL threadComInitialized = FALSE;
#ifdef PA_WASAPI_LOG_TIME_SLOTS
    LONGLONG startWaitTime;
#endif

    // Notify: state
    NotifyStateChanged(stream, paWasapiStreamStateThreadPrepare, ERROR_SUCCESS);

    // Prepare COM pointers
    if (!PrepareComPointers(stream, &threadComInitialized))
        return (UINT32)paUnanticipatedHostError;

    // Request fine (1 ms) granularity of the system timer functions to guarantee correct logic around WaitForSingleObject
    SystemTimer_SetGranularity(&timer, 1);

    // Calculate sleep time of the processing loop (inside WaitForSingleObject)
    sleepTime = ConfigureLoopSleepTimeAndScheduler(stream, &scheduler);

    // Setup data processors
    defaultProcessor.processor = WaspiHostProcessingLoop;
    defaultProcessor.userData  = stream;
    processor[S_INPUT] = (stream->hostProcessOverrideInput.processor != NULL ? stream->hostProcessOverrideInput : defaultProcessor);
    processor[S_OUTPUT] = (stream->hostProcessOverrideOutput.processor != NULL ? stream->hostProcessOverrideOutput : defaultProcessor);

    // Boost thread priority
    PaWasapi_ThreadPriorityBoost((void **)&stream->hAvTask, stream->nThreadPriority);

    // Signal: stream running
    stream->running = TRUE;

    // Notify: thread started
    SetEvent(stream->hThreadStart);

    // Initialize event & start INPUT stream
    if (stream->in.clientProc)
    {
        if ((hr = IAudioClient_Start(stream->in.clientProc)) != S_OK)
        {
            LogHostError(hr);
            goto thread_error;
        }
    }

    // Initialize event & start OUTPUT stream
    if (stream->out.clientProc)
    {
        // Preload buffer (obligatory, othervise ->Start() will fail), avoid processing
        // when in full-duplex mode as it requires input processing as well
        if (!PA_WASAPI__IS_FULLDUPLEX(stream))
        {
            UINT32 frames = 0;
            if ((hr = _PollGetOutputFramesAvailable(stream, &frames)) == S_OK)
            {
                if (stream->bufferMode == paUtilFixedHostBufferSize)
                {
                    // It is important to preload whole host buffer to avoid underruns/glitches when stream is started,
                    // for more details see the discussion: https://github.com/PortAudio/portaudio/issues/303
                    while (frames >= stream->out.framesPerBuffer)
                    {
                        if ((hr = ProcessOutputBuffer(stream, processor, stream->out.framesPerBuffer)) != S_OK)
                        {
                            LogHostError(hr); // not fatal, just log
                            break;
                        }

                        frames -= stream->out.framesPerBuffer;
                    }
                }
                else
                {
                    // Some devices may not start (will get stuck with 0 ready frames) if data not prefetched
                    if (frames == 0)
                        frames = stream->out.framesPerBuffer;

                    // USB DACs report large buffer in Exclusive mode and if it is filled fully will stuck in
                    // non playing state, e.g. IAudioClient_GetCurrentPadding() will start reporting max buffer size
                    // constantly, thus preload data size equal to the user buffer to allow process going
                    if ((stream->out.shareMode == AUDCLNT_SHAREMODE_EXCLUSIVE) && (frames >= (stream->out.framesPerBuffer * 2)))
                        frames -= stream->out.framesPerBuffer;

                    if ((hr = ProcessOutputBuffer(stream, processor, frames)) != S_OK)
                    {
                        LogHostError(hr); // not fatal, just log
                    }
                }
            }
            else
            {
                LogHostError(hr); // not fatal, just log
            }
        }

        // Start
        if ((hr = IAudioClient_Start(stream->out.clientProc)) != S_OK)
        {
            LogHostError(hr);
            goto thread_error;
        }
    }

    // Notify: state
    NotifyStateChanged(stream, paWasapiStreamStateThreadStart, ERROR_SUCCESS);

#ifdef PA_WASAPI_LOG_TIME_SLOTS
    startWaitTime = SystemTimer_GetTime(&timer);
#endif

    if (!PA_WASAPI__IS_FULLDUPLEX(stream))
    {
        // Processing Loop
        while (WaitForSingleObject(stream->hCloseRequest, nextSleepTime) == WAIT_TIMEOUT)
        {
            startTime = SystemTimer_GetTime(&timer);

        #ifdef PA_WASAPI_LOG_TIME_SLOTS
            printf("[%d|%d],", nextSleepTime, (INT32)(startTime - startWaitTime));
        #endif

            for (i = 0; i < S_COUNT; ++i)
            {
                // Process S_INPUT/S_OUTPUT
                switch (i)
                {
                // Input stream
                case S_INPUT: {

                    if (stream->captureClient == NULL)
                        break;

                    if ((hr = ProcessInputBuffer(stream, processor)) != S_OK)
                    {
                        LogHostError(hr);
                        goto thread_error;
                    }

                    break; }

                // Output stream
                case S_OUTPUT: {

                    UINT32 framesAvail;

                    if (stream->renderClient == NULL)
                        break;

                    // Get available frames
                    if ((hr = _PollGetOutputFramesAvailable(stream, &framesAvail)) != S_OK)
                    {
                        LogHostError(hr);
                        goto thread_error;
                    }

                    // Output data to the user callback
                    if (stream->bufferMode == paUtilFixedHostBufferSize)
                    {
                        UINT32 framesProc = stream->out.framesPerBuffer;

                        // If we got less frames avoid sleeping again as it might be the corner case and buffer
                        // has sufficient number of frames now, in case 'out.framesPerBuffer' is 1/2 of the host
                        // buffer sleeping again may cause underruns. Do short busy waiting (normally might take
                        // 1-2 iterations)
                        if (framesAvail < framesProc)
                        {
                            nextSleepTime = 0;
                            continue;
                        }

                        while (framesAvail >= framesProc)
                        {
                            if ((hr = ProcessOutputBuffer(stream, processor, framesProc)) != S_OK)
                            {
                                LogHostError(hr);
                                goto thread_error;
                            }

                            framesAvail -= framesProc;
                        }
                    }
                    else
                    if (framesAvail != 0)
                    {
                        if ((hr = ProcessOutputBuffer(stream, processor, framesAvail)) != S_OK)
                        {
                            LogHostError(hr);
                            goto thread_error;
                        }
                    }

                    break; }
                }
            }

            // Get next sleep time
            nextSleepTime = GetNextSleepTime(&timer, &scheduler, startTime, sleepTime);

        #ifdef PA_WASAPI_LOG_TIME_SLOTS
            startWaitTime = SystemTimer_GetTime(&timer);
        #endif
        }
    }
    else
    {
        // Processing Loop (full-duplex)
        while (WaitForSingleObject(stream->hCloseRequest, nextSleepTime) == WAIT_TIMEOUT)
        {
            UINT32 i_frames = 0, i_processed = 0, o_frames = 0;
            BYTE *i_data = NULL, *o_data = NULL, *o_data_host = NULL;
            DWORD i_flags = 0;

            startTime = SystemTimer_GetTime(&timer);

        #ifdef PA_WASAPI_LOG_TIME_SLOTS
            printf("[%d|%d],", nextSleepTime, (INT32)(startTime - startWaitTime));
        #endif

            // get available frames
            if ((hr = _PollGetOutputFramesAvailable(stream, &o_frames)) != S_OK)
            {
                LogHostError(hr);
                break;
            }

            while (o_frames != 0)
            {
                // get host input buffer
                if ((hr = IAudioCaptureClient_GetBuffer(stream->captureClient, &i_data, &i_frames, &i_flags, NULL, NULL)) != S_OK)
                {
                    if (hr == AUDCLNT_S_BUFFER_EMPTY)
                        break; // no data in capture buffer

                    LogHostError(hr);
                    break;
                }

                // process equal amount of frames
                if (o_frames >= i_frames)
                {
                    // process input amount of frames
                    UINT32 o_processed = i_frames;

                    // get host output buffer
                    if ((hr = IAudioRenderClient_GetBuffer(stream->renderClient, o_processed, &o_data)) == S_OK)
                    {
                        // processed amount of i_frames
                        i_processed = i_frames;
                        o_data_host = o_data;

                        // convert output mono
                        if (stream->out.monoMixer)
                        {
                            UINT32 mono_frames_size = o_processed * (stream->out.wavex.Format.wBitsPerSample / 8);
                            // expand buffer
                            if (mono_frames_size > stream->out.monoBufferSize)
                            {
                                stream->out.monoBuffer = PaWasapi_ReallocateMemory(stream->out.monoBuffer, (stream->out.monoBufferSize = mono_frames_size));
                                if (stream->out.monoBuffer == NULL)
                                {
                                    // release input buffer
                                    IAudioCaptureClient_ReleaseBuffer(stream->captureClient, 0);
                                    // release output buffer
                                    IAudioRenderClient_ReleaseBuffer(stream->renderClient, 0, 0);

                                    LogPaError(paInsufficientMemory);
                                    goto thread_error;
                                }
                            }

                            // replace buffer pointer
                            o_data = (BYTE *)stream->out.monoBuffer;
                        }

                        // convert input mono
                        if (stream->in.monoMixer)
                        {
                            UINT32 mono_frames_size = i_processed * (stream->in.wavex.Format.wBitsPerSample / 8);
                            // expand buffer
                            if (mono_frames_size > stream->in.monoBufferSize)
                            {
                                stream->in.monoBuffer = PaWasapi_ReallocateMemory(stream->in.monoBuffer, (stream->in.monoBufferSize = mono_frames_size));
                                if (stream->in.monoBuffer == NULL)
                                {
                                    // release input buffer
                                    IAudioCaptureClient_ReleaseBuffer(stream->captureClient, 0);
                                    // release output buffer
                                    IAudioRenderClient_ReleaseBuffer(stream->renderClient, 0, 0);

                                    LogPaError(paInsufficientMemory);
                                    goto thread_error;
                                }
                            }

                            // mix 2 to 1 input channels
                            stream->in.monoMixer(stream->in.monoBuffer, i_data, i_processed);

                            // replace buffer pointer
                            i_data = (BYTE *)stream->in.monoBuffer;
                        }

                        // process
                        processor[S_FULLDUPLEX].processor(i_data, i_processed, o_data, o_processed, processor[S_FULLDUPLEX].userData);

                        // mix 1 to 2 output channels
                        if (stream->out.monoBuffer)
                            stream->out.monoMixer(o_data_host, stream->out.monoBuffer, o_processed);

                        // release host output buffer
                        if ((hr = IAudioRenderClient_ReleaseBuffer(stream->renderClient, o_processed, 0)) != S_OK)
                            LogHostError(hr);

                        o_frames -= o_processed;
                    }
                    else
                    {
                        if (stream->out.shareMode != AUDCLNT_SHAREMODE_SHARED)
                            LogHostError(hr); // be silent in shared mode, try again next time
                    }
                }
                else
                {
                    i_processed = 0;
                    goto fd_release_buffer_in;
                }

fd_release_buffer_in:

                // release host input buffer
                if ((hr = IAudioCaptureClient_ReleaseBuffer(stream->captureClient, i_processed)) != S_OK)
                {
                    LogHostError(hr);
                    break;
                }

                // break processing, input hasn't been accumulated yet
                if (i_processed == 0)
                    break;
            }

            // Get next sleep time
            nextSleepTime = GetNextSleepTime(&timer, &scheduler, startTime, sleepTime);

        #ifdef PA_WASAPI_LOG_TIME_SLOTS
            startWaitTime = SystemTimer_GetTime(&timer);
        #endif
        }
    }

thread_end:

    // Process stop
    _StreamOnStop(stream);

    // Release unmarshaled COM pointers
    FinishComPointers(stream, threadComInitialized);

    // Restore system timer granularity
    SystemTimer_RestoreGranularity(&timer);

    // Notify: not running
    stream->running = FALSE;

    // Notify: thread exited
    SetEvent(stream->hThreadExit);

    // Notify: state
    NotifyStateChanged(stream, paWasapiStreamStateThreadStop, hr);

    return 0;

thread_error:

    // Prevent deadlocking in Pa_StreamStart
    SetEvent(stream->hThreadStart);

    // Exit
    goto thread_end;
}

// ------------------------------------------------------------------------------------------
void *PaWasapi_ReallocateMemory(void *prev, size_t size)
{
    void *ret = realloc(prev, size);
    if (ret == NULL)
    {
        PaWasapi_FreeMemory(prev);
        return NULL;
    }
    return ret;
}

// ------------------------------------------------------------------------------------------
void PaWasapi_FreeMemory(void *ptr)
{
    free(ptr);
}