File size: 3,308 Bytes
7142654 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 | #include "DeviceEnumerator.h"
#include <iostream>
std::map<int, Device> DeviceEnumerator::getVideoDevicesMap() {
return getDevicesMap(CLSID_VideoInputDeviceCategory);
}
std::map<int, Device> DeviceEnumerator::getAudioDevicesMap() {
return getDevicesMap(CLSID_AudioInputDeviceCategory);
}
// Returns a map of id and devices that can be used
std::map<int, Device> DeviceEnumerator::getDevicesMap(const GUID deviceClass)
{
std::map<int, Device> deviceMap;
// TODO add back? Calling from C# seems to not need this
//HRESULT hr = CoInitialize(nullptr);
//if (FAILED(hr)) {
// return deviceMap; // Empty deviceMap as an error
//}
// Create the System Device Enumerator
ICreateDevEnum *pDevEnum;
HRESULT hr = CoCreateInstance(CLSID_SystemDeviceEnum, NULL, CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&pDevEnum));
// If succeeded, create an enumerator for the category
IEnumMoniker *pEnum = NULL;
if (SUCCEEDED(hr)) {
hr = pDevEnum->CreateClassEnumerator(deviceClass, &pEnum, 0);
if (hr == S_FALSE) {
hr = VFW_E_NOT_FOUND;
}
pDevEnum->Release();
}
// Now we check if the enumerator creation succeeded
int deviceId = -1;
if (SUCCEEDED(hr)) {
// Fill the map with id and friendly device name
IMoniker *pMoniker = NULL;
while (pEnum->Next(1, &pMoniker, NULL) == S_OK) {
IPropertyBag *pPropBag;
HRESULT hr = pMoniker->BindToStorage(0, 0, IID_PPV_ARGS(&pPropBag));
if (FAILED(hr)) {
pMoniker->Release();
continue;
}
// Create variant to hold data
VARIANT var;
VariantInit(&var);
std::string deviceName;
std::string devicePath;
// Read FriendlyName or Description
hr = pPropBag->Read(L"Description", &var, 0); // Read description
if (FAILED(hr)) {
// If description fails, try with the friendly name
hr = pPropBag->Read(L"FriendlyName", &var, 0);
}
// If still fails, continue with next device
if (FAILED(hr)) {
VariantClear(&var);
continue;
}
// Convert to string
else {
deviceName = ConvertBSTRToMBS(var.bstrVal);
}
VariantClear(&var); // We clean the variable in order to read the next value
// We try to read the DevicePath
hr = pPropBag->Read(L"DevicePath", &var, 0);
if (FAILED(hr)) {
VariantClear(&var);
continue; // If it fails we continue with next device
}
else {
devicePath = ConvertBSTRToMBS(var.bstrVal);
}
// We populate the map
deviceId++;
Device currentDevice;
currentDevice.id = deviceId;
currentDevice.deviceName = deviceName;
currentDevice.devicePath = devicePath;
deviceMap[deviceId] = currentDevice;
}
pEnum->Release();
}
CoUninitialize();
return deviceMap;
}
/*
This two methods were taken from
https://stackoverflow.com/questions/6284524/bstr-to-stdstring-stdwstring-and-vice-versa
*/
std::string DeviceEnumerator::ConvertBSTRToMBS(BSTR bstr)
{
int wslen = ::SysStringLen(bstr);
return ConvertWCSToMBS((wchar_t*)bstr, wslen);
}
std::string DeviceEnumerator::ConvertWCSToMBS(const wchar_t* pstr, long wslen)
{
int len = ::WideCharToMultiByte(CP_ACP, 0, pstr, wslen, NULL, 0, NULL, NULL);
std::string dblstr(len, '\0');
len = ::WideCharToMultiByte(CP_ACP, 0 /* no flags */,
pstr, wslen /* not necessary NULL-terminated */,
&dblstr[0], len,
NULL, NULL /* no default char */);
return dblstr;
}
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