| /* | |
| * Copyright (C) 2011-2013 Michael Niedermayer (michaelni@gmx.at) | |
| * | |
| * This file is part of libswresample | |
| * | |
| * libswresample is free software; you can redistribute it and/or | |
| * modify it under the terms of the GNU Lesser General Public | |
| * License as published by the Free Software Foundation; either | |
| * version 2.1 of the License, or (at your option) any later version. | |
| * | |
| * libswresample is distributed in the hope that it will be useful, | |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| * Lesser General Public License for more details. | |
| * | |
| * You should have received a copy of the GNU Lesser General Public | |
| * License along with libswresample; if not, write to the Free Software | |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
| */ | |
| /** | |
| * @file | |
| * @ingroup lswr | |
| * libswresample public header | |
| */ | |
| /** | |
| * @defgroup lswr libswresample | |
| * @{ | |
| * | |
| * Audio resampling, sample format conversion and mixing library. | |
| * | |
| * Interaction with lswr is done through SwrContext, which is | |
| * allocated with swr_alloc() or swr_alloc_set_opts2(). It is opaque, so all parameters | |
| * must be set with the @ref avoptions API. | |
| * | |
| * The first thing you will need to do in order to use lswr is to allocate | |
| * SwrContext. This can be done with swr_alloc() or swr_alloc_set_opts2(). If you | |
| * are using the former, you must set options through the @ref avoptions API. | |
| * The latter function provides the same feature, but it allows you to set some | |
| * common options in the same statement. | |
| * | |
| * For example the following code will setup conversion from planar float sample | |
| * format to interleaved signed 16-bit integer, downsampling from 48kHz to | |
| * 44.1kHz and downmixing from 5.1 channels to stereo (using the default mixing | |
| * matrix). This is using the swr_alloc() function. | |
| * @code | |
| * SwrContext *swr = swr_alloc(); | |
| * av_opt_set_chlayout(swr, "in_chlayout", &(AVChannelLayout)AV_CHANNEL_LAYOUT_5POINT1, 0); | |
| * av_opt_set_chlayout(swr, "out_chlayout", &(AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO, 0); | |
| * av_opt_set_int(swr, "in_sample_rate", 48000, 0); | |
| * av_opt_set_int(swr, "out_sample_rate", 44100, 0); | |
| * av_opt_set_sample_fmt(swr, "in_sample_fmt", AV_SAMPLE_FMT_FLTP, 0); | |
| * av_opt_set_sample_fmt(swr, "out_sample_fmt", AV_SAMPLE_FMT_S16, 0); | |
| * @endcode | |
| * | |
| * The same job can be done using swr_alloc_set_opts2() as well: | |
| * @code | |
| * SwrContext *swr = NULL; | |
| * int ret = swr_alloc_set_opts2(&swr, // we're allocating a new context | |
| * &(AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO, // out_ch_layout | |
| * AV_SAMPLE_FMT_S16, // out_sample_fmt | |
| * 44100, // out_sample_rate | |
| * &(AVChannelLayout)AV_CHANNEL_LAYOUT_5POINT1, // in_ch_layout | |
| * AV_SAMPLE_FMT_FLTP, // in_sample_fmt | |
| * 48000, // in_sample_rate | |
| * 0, // log_offset | |
| * NULL); // log_ctx | |
| * @endcode | |
| * | |
| * Once all values have been set, it must be initialized with swr_init(). If | |
| * you need to change the conversion parameters, you can change the parameters | |
| * using @ref avoptions, as described above in the first example; or by using | |
| * swr_alloc_set_opts2(), but with the first argument the allocated context. | |
| * You must then call swr_init() again. | |
| * | |
| * The conversion itself is done by repeatedly calling swr_convert(). | |
| * Note that the samples may get buffered in swr if you provide insufficient | |
| * output space or if sample rate conversion is done, which requires "future" | |
| * samples. Samples that do not require future input can be retrieved at any | |
| * time by using swr_convert() (in_count can be set to 0). | |
| * At the end of conversion the resampling buffer can be flushed by calling | |
| * swr_convert() with NULL in and 0 in_count. | |
| * | |
| * The samples used in the conversion process can be managed with the libavutil | |
| * @ref lavu_sampmanip "samples manipulation" API, including av_samples_alloc() | |
| * function used in the following example. | |
| * | |
| * The delay between input and output, can at any time be found by using | |
| * swr_get_delay(). | |
| * | |
| * The following code demonstrates the conversion loop assuming the parameters | |
| * from above and caller-defined functions get_input() and handle_output(): | |
| * @code | |
| * uint8_t **input; | |
| * int in_samples; | |
| * | |
| * while (get_input(&input, &in_samples)) { | |
| * uint8_t *output; | |
| * int out_samples = av_rescale_rnd(swr_get_delay(swr, 48000) + | |
| * in_samples, 44100, 48000, AV_ROUND_UP); | |
| * av_samples_alloc(&output, NULL, 2, out_samples, | |
| * AV_SAMPLE_FMT_S16, 0); | |
| * out_samples = swr_convert(swr, &output, out_samples, | |
| * input, in_samples); | |
| * handle_output(output, out_samples); | |
| * av_freep(&output); | |
| * } | |
| * @endcode | |
| * | |
| * When the conversion is finished, the conversion | |
| * context and everything associated with it must be freed with swr_free(). | |
| * A swr_close() function is also available, but it exists mainly for | |
| * compatibility with libavresample, and is not required to be called. | |
| * | |
| * There will be no memory leak if the data is not completely flushed before | |
| * swr_free(). | |
| */ | |
| /* When included as part of the ffmpeg build, only include the major version | |
| * to avoid unnecessary rebuilds. When included externally, keep including | |
| * the full version information. */ | |
| /** | |
| * @name Option constants | |
| * These constants are used for the @ref avoptions interface for lswr. | |
| * @{ | |
| * | |
| */ | |
| //TODO use int resample ? | |
| //long term TODO can we enable this dynamically? | |
| /** Dithering algorithms */ | |
| enum SwrDitherType { | |
| SWR_DITHER_NONE = 0, | |
| SWR_DITHER_RECTANGULAR, | |
| SWR_DITHER_TRIANGULAR, | |
| SWR_DITHER_TRIANGULAR_HIGHPASS, | |
| SWR_DITHER_NS = 64, ///< not part of API/ABI | |
| SWR_DITHER_NS_LIPSHITZ, | |
| SWR_DITHER_NS_F_WEIGHTED, | |
| SWR_DITHER_NS_MODIFIED_E_WEIGHTED, | |
| SWR_DITHER_NS_IMPROVED_E_WEIGHTED, | |
| SWR_DITHER_NS_SHIBATA, | |
| SWR_DITHER_NS_LOW_SHIBATA, | |
| SWR_DITHER_NS_HIGH_SHIBATA, | |
| SWR_DITHER_NB, ///< not part of API/ABI | |
| }; | |
| /** Resampling Engines */ | |
| enum SwrEngine { | |
| SWR_ENGINE_SWR, /**< SW Resampler */ | |
| SWR_ENGINE_SOXR, /**< SoX Resampler */ | |
| SWR_ENGINE_NB, ///< not part of API/ABI | |
| }; | |
| /** Resampling Filter Types */ | |
| enum SwrFilterType { | |
| SWR_FILTER_TYPE_CUBIC, /**< Cubic */ | |
| SWR_FILTER_TYPE_BLACKMAN_NUTTALL, /**< Blackman Nuttall windowed sinc */ | |
| SWR_FILTER_TYPE_KAISER, /**< Kaiser windowed sinc */ | |
| }; | |
| /** | |
| * @} | |
| */ | |
| /** | |
| * The libswresample context. Unlike libavcodec and libavformat, this structure | |
| * is opaque. This means that if you would like to set options, you must use | |
| * the @ref avoptions API and cannot directly set values to members of the | |
| * structure. | |
| */ | |
| typedef struct SwrContext SwrContext; | |
| /** | |
| * Get the AVClass for SwrContext. It can be used in combination with | |
| * AV_OPT_SEARCH_FAKE_OBJ for examining options. | |
| * | |
| * @see av_opt_find(). | |
| * @return the AVClass of SwrContext | |
| */ | |
| const AVClass *swr_get_class(void); | |
| /** | |
| * @name SwrContext constructor functions | |
| * @{ | |
| */ | |
| /** | |
| * Allocate SwrContext. | |
| * | |
| * If you use this function you will need to set the parameters (manually or | |
| * with swr_alloc_set_opts2()) before calling swr_init(). | |
| * | |
| * @see swr_alloc_set_opts2(), swr_init(), swr_free() | |
| * @return NULL on error, allocated context otherwise | |
| */ | |
| struct SwrContext *swr_alloc(void); | |
| /** | |
| * Initialize context after user parameters have been set. | |
| * @note The context must be configured using the AVOption API. | |
| * | |
| * @see av_opt_set_int() | |
| * @see av_opt_set_dict() | |
| * | |
| * @param[in,out] s Swr context to initialize | |
| * @return AVERROR error code in case of failure. | |
| */ | |
| int swr_init(struct SwrContext *s); | |
| /** | |
| * Check whether an swr context has been initialized or not. | |
| * | |
| * @param[in] s Swr context to check | |
| * @see swr_init() | |
| * @return positive if it has been initialized, 0 if not initialized | |
| */ | |
| int swr_is_initialized(struct SwrContext *s); | |
| /** | |
| * Allocate SwrContext if needed and set/reset common parameters. | |
| * | |
| * This function does not require *ps to be allocated with swr_alloc(). On the | |
| * other hand, swr_alloc() can use swr_alloc_set_opts2() to set the parameters | |
| * on the allocated context. | |
| * | |
| * @param ps Pointer to an existing Swr context if available, or to NULL if not. | |
| * On success, *ps will be set to the allocated context. | |
| * @param out_ch_layout output channel layout (e.g. AV_CHANNEL_LAYOUT_*) | |
| * @param out_sample_fmt output sample format (AV_SAMPLE_FMT_*). | |
| * @param out_sample_rate output sample rate (frequency in Hz) | |
| * @param in_ch_layout input channel layout (e.g. AV_CHANNEL_LAYOUT_*) | |
| * @param in_sample_fmt input sample format (AV_SAMPLE_FMT_*). | |
| * @param in_sample_rate input sample rate (frequency in Hz) | |
| * @param log_offset logging level offset | |
| * @param log_ctx parent logging context, can be NULL | |
| * | |
| * @see swr_init(), swr_free() | |
| * @return 0 on success, a negative AVERROR code on error. | |
| * On error, the Swr context is freed and *ps set to NULL. | |
| */ | |
| int swr_alloc_set_opts2(struct SwrContext **ps, | |
| const AVChannelLayout *out_ch_layout, enum AVSampleFormat out_sample_fmt, int out_sample_rate, | |
| const AVChannelLayout *in_ch_layout, enum AVSampleFormat in_sample_fmt, int in_sample_rate, | |
| int log_offset, void *log_ctx); | |
| /** | |
| * @} | |
| * | |
| * @name SwrContext destructor functions | |
| * @{ | |
| */ | |
| /** | |
| * Free the given SwrContext and set the pointer to NULL. | |
| * | |
| * @param[in] s a pointer to a pointer to Swr context | |
| */ | |
| void swr_free(struct SwrContext **s); | |
| /** | |
| * Closes the context so that swr_is_initialized() returns 0. | |
| * | |
| * The context can be brought back to life by running swr_init(), | |
| * swr_init() can also be used without swr_close(). | |
| * This function is mainly provided for simplifying the usecase | |
| * where one tries to support libavresample and libswresample. | |
| * | |
| * @param[in,out] s Swr context to be closed | |
| */ | |
| void swr_close(struct SwrContext *s); | |
| /** | |
| * @} | |
| * | |
| * @name Core conversion functions | |
| * @{ | |
| */ | |
| /** Convert audio. | |
| * | |
| * in and in_count can be set to 0 to flush the last few samples out at the | |
| * end. | |
| * | |
| * If more input is provided than output space, then the input will be buffered. | |
| * You can avoid this buffering by using swr_get_out_samples() to retrieve an | |
| * upper bound on the required number of output samples for the given number of | |
| * input samples. Conversion will run directly without copying whenever possible. | |
| * | |
| * @param s allocated Swr context, with parameters set | |
| * @param out output buffers, only the first one need be set in case of packed audio | |
| * @param out_count amount of space available for output in samples per channel | |
| * @param in input buffers, only the first one need to be set in case of packed audio | |
| * @param in_count number of input samples available in one channel | |
| * | |
| * @return number of samples output per channel, negative value on error | |
| */ | |
| int swr_convert(struct SwrContext *s, uint8_t * const *out, int out_count, | |
| const uint8_t * const *in , int in_count); | |
| /** | |
| * Convert the next timestamp from input to output | |
| * timestamps are in 1/(in_sample_rate * out_sample_rate) units. | |
| * | |
| * @note There are 2 slightly differently behaving modes. | |
| * @li When automatic timestamp compensation is not used, (min_compensation >= FLT_MAX) | |
| * in this case timestamps will be passed through with delays compensated | |
| * @li When automatic timestamp compensation is used, (min_compensation < FLT_MAX) | |
| * in this case the output timestamps will match output sample numbers. | |
| * See ffmpeg-resampler(1) for the two modes of compensation. | |
| * | |
| * @param[in] s initialized Swr context | |
| * @param[in] pts timestamp for the next input sample, INT64_MIN if unknown | |
| * @see swr_set_compensation(), swr_drop_output(), and swr_inject_silence() are | |
| * function used internally for timestamp compensation. | |
| * @return the output timestamp for the next output sample | |
| */ | |
| int64_t swr_next_pts(struct SwrContext *s, int64_t pts); | |
| /** | |
| * @} | |
| * | |
| * @name Low-level option setting functions | |
| * These functons provide a means to set low-level options that is not possible | |
| * with the AVOption API. | |
| * @{ | |
| */ | |
| /** | |
| * Activate resampling compensation ("soft" compensation). This function is | |
| * internally called when needed in swr_next_pts(). | |
| * | |
| * @param[in,out] s allocated Swr context. If it is not initialized, | |
| * or SWR_FLAG_RESAMPLE is not set, swr_init() is | |
| * called with the flag set. | |
| * @param[in] sample_delta delta in PTS per sample | |
| * @param[in] compensation_distance number of samples to compensate for | |
| * @return >= 0 on success, AVERROR error codes if: | |
| * @li @c s is NULL, | |
| * @li @c compensation_distance is less than 0, | |
| * @li @c compensation_distance is 0 but sample_delta is not, | |
| * @li compensation unsupported by resampler, or | |
| * @li swr_init() fails when called. | |
| */ | |
| int swr_set_compensation(struct SwrContext *s, int sample_delta, int compensation_distance); | |
| /** | |
| * Set a customized input channel mapping. | |
| * | |
| * @param[in,out] s allocated Swr context, not yet initialized | |
| * @param[in] channel_map customized input channel mapping (array of channel | |
| * indexes, -1 for a muted channel) | |
| * @return >= 0 on success, or AVERROR error code in case of failure. | |
| */ | |
| int swr_set_channel_mapping(struct SwrContext *s, const int *channel_map); | |
| /** | |
| * Generate a channel mixing matrix. | |
| * | |
| * This function is the one used internally by libswresample for building the | |
| * default mixing matrix. It is made public just as a utility function for | |
| * building custom matrices. | |
| * | |
| * @param in_layout input channel layout | |
| * @param out_layout output channel layout | |
| * @param center_mix_level mix level for the center channel | |
| * @param surround_mix_level mix level for the surround channel(s) | |
| * @param lfe_mix_level mix level for the low-frequency effects channel | |
| * @param rematrix_maxval if 1.0, coefficients will be normalized to prevent | |
| * overflow. if INT_MAX, coefficients will not be | |
| * normalized. | |
| * @param[out] matrix mixing coefficients; matrix[i + stride * o] is | |
| * the weight of input channel i in output channel o. | |
| * @param stride distance between adjacent input channels in the | |
| * matrix array | |
| * @param matrix_encoding matrixed stereo downmix mode (e.g. dplii) | |
| * @param log_ctx parent logging context, can be NULL | |
| * @return 0 on success, negative AVERROR code on failure | |
| */ | |
| int swr_build_matrix2(const AVChannelLayout *in_layout, const AVChannelLayout *out_layout, | |
| double center_mix_level, double surround_mix_level, | |
| double lfe_mix_level, double maxval, | |
| double rematrix_volume, double *matrix, | |
| ptrdiff_t stride, enum AVMatrixEncoding matrix_encoding, | |
| void *log_context); | |
| /** | |
| * Set a customized remix matrix. | |
| * | |
| * @param s allocated Swr context, not yet initialized | |
| * @param matrix remix coefficients; matrix[i + stride * o] is | |
| * the weight of input channel i in output channel o | |
| * @param stride offset between lines of the matrix | |
| * @return >= 0 on success, or AVERROR error code in case of failure. | |
| */ | |
| int swr_set_matrix(struct SwrContext *s, const double *matrix, int stride); | |
| /** | |
| * @} | |
| * | |
| * @name Sample handling functions | |
| * @{ | |
| */ | |
| /** | |
| * Drops the specified number of output samples. | |
| * | |
| * This function, along with swr_inject_silence(), is called by swr_next_pts() | |
| * if needed for "hard" compensation. | |
| * | |
| * @param s allocated Swr context | |
| * @param count number of samples to be dropped | |
| * | |
| * @return >= 0 on success, or a negative AVERROR code on failure | |
| */ | |
| int swr_drop_output(struct SwrContext *s, int count); | |
| /** | |
| * Injects the specified number of silence samples. | |
| * | |
| * This function, along with swr_drop_output(), is called by swr_next_pts() | |
| * if needed for "hard" compensation. | |
| * | |
| * @param s allocated Swr context | |
| * @param count number of samples to be dropped | |
| * | |
| * @return >= 0 on success, or a negative AVERROR code on failure | |
| */ | |
| int swr_inject_silence(struct SwrContext *s, int count); | |
| /** | |
| * Gets the delay the next input sample will experience relative to the next output sample. | |
| * | |
| * Swresample can buffer data if more input has been provided than available | |
| * output space, also converting between sample rates needs a delay. | |
| * This function returns the sum of all such delays. | |
| * The exact delay is not necessarily an integer value in either input or | |
| * output sample rate. Especially when downsampling by a large value, the | |
| * output sample rate may be a poor choice to represent the delay, similarly | |
| * for upsampling and the input sample rate. | |
| * | |
| * @param s swr context | |
| * @param base timebase in which the returned delay will be: | |
| * @li if it's set to 1 the returned delay is in seconds | |
| * @li if it's set to 1000 the returned delay is in milliseconds | |
| * @li if it's set to the input sample rate then the returned | |
| * delay is in input samples | |
| * @li if it's set to the output sample rate then the returned | |
| * delay is in output samples | |
| * @li if it's the least common multiple of in_sample_rate and | |
| * out_sample_rate then an exact rounding-free delay will be | |
| * returned | |
| * @returns the delay in 1 / @c base units. | |
| */ | |
| int64_t swr_get_delay(struct SwrContext *s, int64_t base); | |
| /** | |
| * Find an upper bound on the number of samples that the next swr_convert | |
| * call will output, if called with in_samples of input samples. This | |
| * depends on the internal state, and anything changing the internal state | |
| * (like further swr_convert() calls) will may change the number of samples | |
| * swr_get_out_samples() returns for the same number of input samples. | |
| * | |
| * @param in_samples number of input samples. | |
| * @note any call to swr_inject_silence(), swr_convert(), swr_next_pts() | |
| * or swr_set_compensation() invalidates this limit | |
| * @note it is recommended to pass the correct available buffer size | |
| * to all functions like swr_convert() even if swr_get_out_samples() | |
| * indicates that less would be used. | |
| * @returns an upper bound on the number of samples that the next swr_convert | |
| * will output or a negative value to indicate an error | |
| */ | |
| int swr_get_out_samples(struct SwrContext *s, int in_samples); | |
| /** | |
| * @} | |
| * | |
| * @name Configuration accessors | |
| * @{ | |
| */ | |
| /** | |
| * Return the @ref LIBSWRESAMPLE_VERSION_INT constant. | |
| * | |
| * This is useful to check if the build-time libswresample has the same version | |
| * as the run-time one. | |
| * | |
| * @returns the unsigned int-typed version | |
| */ | |
| unsigned swresample_version(void); | |
| /** | |
| * Return the swr build-time configuration. | |
| * | |
| * @returns the build-time @c ./configure flags | |
| */ | |
| const char *swresample_configuration(void); | |
| /** | |
| * Return the swr license. | |
| * | |
| * @returns the license of libswresample, determined at build-time | |
| */ | |
| const char *swresample_license(void); | |
| /** | |
| * @} | |
| * | |
| * @name AVFrame based API | |
| * @{ | |
| */ | |
| /** | |
| * Convert the samples in the input AVFrame and write them to the output AVFrame. | |
| * | |
| * Input and output AVFrames must have channel_layout, sample_rate and format set. | |
| * | |
| * If the output AVFrame does not have the data pointers allocated the nb_samples | |
| * field will be set using av_frame_get_buffer() | |
| * is called to allocate the frame. | |
| * | |
| * The output AVFrame can be NULL or have fewer allocated samples than required. | |
| * In this case, any remaining samples not written to the output will be added | |
| * to an internal FIFO buffer, to be returned at the next call to this function | |
| * or to swr_convert(). | |
| * | |
| * If converting sample rate, there may be data remaining in the internal | |
| * resampling delay buffer. swr_get_delay() tells the number of | |
| * remaining samples. To get this data as output, call this function or | |
| * swr_convert() with NULL input. | |
| * | |
| * If the SwrContext configuration does not match the output and | |
| * input AVFrame settings the conversion does not take place and depending on | |
| * which AVFrame is not matching AVERROR_OUTPUT_CHANGED, AVERROR_INPUT_CHANGED | |
| * or the result of a bitwise-OR of them is returned. | |
| * | |
| * @see swr_delay() | |
| * @see swr_convert() | |
| * @see swr_get_delay() | |
| * | |
| * @param swr audio resample context | |
| * @param output output AVFrame | |
| * @param input input AVFrame | |
| * @return 0 on success, AVERROR on failure or nonmatching | |
| * configuration. | |
| */ | |
| int swr_convert_frame(SwrContext *swr, | |
| AVFrame *output, const AVFrame *input); | |
| /** | |
| * Configure or reconfigure the SwrContext using the information | |
| * provided by the AVFrames. | |
| * | |
| * The original resampling context is reset even on failure. | |
| * The function calls swr_close() internally if the context is open. | |
| * | |
| * @see swr_close(); | |
| * | |
| * @param swr audio resample context | |
| * @param out output AVFrame | |
| * @param in input AVFrame | |
| * @return 0 on success, AVERROR on failure. | |
| */ | |
| int swr_config_frame(SwrContext *swr, const AVFrame *out, const AVFrame *in); | |
| /** | |
| * @} | |
| * @} | |
| */ | |