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swresample.h
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1 /*
2  * Copyright (C) 2011-2013 Michael Niedermayer (michaelni@gmx.at)
3  *
4  * This file is part of libswresample
5  *
6  * libswresample is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * libswresample is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with libswresample; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef SWRESAMPLE_SWRESAMPLE_H
22 #define SWRESAMPLE_SWRESAMPLE_H
23 
24 /**
25  * @file
26  * @ingroup lswr
27  * libswresample public header
28  */
29 
30 /**
31  * @defgroup lswr libswresample
32  * @{
33  *
34  * Audio resampling, sample format conversion and mixing library.
35  *
36  * Interaction with lswr is done through SwrContext, which is
37  * allocated with swr_alloc() or swr_alloc_set_opts2(). It is opaque, so all parameters
38  * must be set with the @ref avoptions API.
39  *
40  * The first thing you will need to do in order to use lswr is to allocate
41  * SwrContext. This can be done with swr_alloc() or swr_alloc_set_opts2(). If you
42  * are using the former, you must set options through the @ref avoptions API.
43  * The latter function provides the same feature, but it allows you to set some
44  * common options in the same statement.
45  *
46  * For example the following code will setup conversion from planar float sample
47  * format to interleaved signed 16-bit integer, downsampling from 48kHz to
48  * 44.1kHz and downmixing from 5.1 channels to stereo (using the default mixing
49  * matrix). This is using the swr_alloc() function.
50  * @code
51  * SwrContext *swr = swr_alloc();
52  * av_opt_set_channel_layout(swr, "in_channel_layout", AV_CH_LAYOUT_5POINT1, 0);
53  * av_opt_set_channel_layout(swr, "out_channel_layout", AV_CH_LAYOUT_STEREO, 0);
54  * av_opt_set_int(swr, "in_sample_rate", 48000, 0);
55  * av_opt_set_int(swr, "out_sample_rate", 44100, 0);
56  * av_opt_set_sample_fmt(swr, "in_sample_fmt", AV_SAMPLE_FMT_FLTP, 0);
57  * av_opt_set_sample_fmt(swr, "out_sample_fmt", AV_SAMPLE_FMT_S16, 0);
58  * @endcode
59  *
60  * The same job can be done using swr_alloc_set_opts2() as well:
61  * @code
62  * SwrContext *swr = NULL;
63  * int ret = swr_alloc_set_opts2(&swr, // we're allocating a new context
64  * &(AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO, // out_ch_layout
65  * AV_SAMPLE_FMT_S16, // out_sample_fmt
66  * 44100, // out_sample_rate
67  * &(AVChannelLayout)AV_CHANNEL_LAYOUT_5POINT1, // in_ch_layout
68  * AV_SAMPLE_FMT_FLTP, // in_sample_fmt
69  * 48000, // in_sample_rate
70  * 0, // log_offset
71  * NULL); // log_ctx
72  * @endcode
73  *
74  * Once all values have been set, it must be initialized with swr_init(). If
75  * you need to change the conversion parameters, you can change the parameters
76  * using @ref avoptions, as described above in the first example; or by using
77  * swr_alloc_set_opts2(), but with the first argument the allocated context.
78  * You must then call swr_init() again.
79  *
80  * The conversion itself is done by repeatedly calling swr_convert().
81  * Note that the samples may get buffered in swr if you provide insufficient
82  * output space or if sample rate conversion is done, which requires "future"
83  * samples. Samples that do not require future input can be retrieved at any
84  * time by using swr_convert() (in_count can be set to 0).
85  * At the end of conversion the resampling buffer can be flushed by calling
86  * swr_convert() with NULL in and 0 in_count.
87  *
88  * The samples used in the conversion process can be managed with the libavutil
89  * @ref lavu_sampmanip "samples manipulation" API, including av_samples_alloc()
90  * function used in the following example.
91  *
92  * The delay between input and output, can at any time be found by using
93  * swr_get_delay().
94  *
95  * The following code demonstrates the conversion loop assuming the parameters
96  * from above and caller-defined functions get_input() and handle_output():
97  * @code
98  * uint8_t **input;
99  * int in_samples;
100  *
101  * while (get_input(&input, &in_samples)) {
102  * uint8_t *output;
103  * int out_samples = av_rescale_rnd(swr_get_delay(swr, 48000) +
104  * in_samples, 44100, 48000, AV_ROUND_UP);
105  * av_samples_alloc(&output, NULL, 2, out_samples,
106  * AV_SAMPLE_FMT_S16, 0);
107  * out_samples = swr_convert(swr, &output, out_samples,
108  * input, in_samples);
109  * handle_output(output, out_samples);
110  * av_freep(&output);
111  * }
112  * @endcode
113  *
114  * When the conversion is finished, the conversion
115  * context and everything associated with it must be freed with swr_free().
116  * A swr_close() function is also available, but it exists mainly for
117  * compatibility with libavresample, and is not required to be called.
118  *
119  * There will be no memory leak if the data is not completely flushed before
120  * swr_free().
121  */
122 
123 #include <stdint.h>
125 #include "libavutil/frame.h"
126 #include "libavutil/samplefmt.h"
127 
129 #ifndef HAVE_AV_CONFIG_H
130 /* When included as part of the ffmpeg build, only include the major version
131  * to avoid unnecessary rebuilds. When included externally, keep including
132  * the full version information. */
133 #include "libswresample/version.h"
134 #endif
135 
136 /**
137  * @name Option constants
138  * These constants are used for the @ref avoptions interface for lswr.
139  * @{
140  *
141  */
142 
143 #define SWR_FLAG_RESAMPLE 1 ///< Force resampling even if equal sample rate
144 //TODO use int resample ?
145 //long term TODO can we enable this dynamically?
146 
147 /** Dithering algorithms */
153 
154  SWR_DITHER_NS = 64, ///< not part of API/ABI
162  SWR_DITHER_NB, ///< not part of API/ABI
163 };
164 
165 /** Resampling Engines */
166 enum SwrEngine {
167  SWR_ENGINE_SWR, /**< SW Resampler */
168  SWR_ENGINE_SOXR, /**< SoX Resampler */
169  SWR_ENGINE_NB, ///< not part of API/ABI
170 };
171 
172 /** Resampling Filter Types */
174  SWR_FILTER_TYPE_CUBIC, /**< Cubic */
175  SWR_FILTER_TYPE_BLACKMAN_NUTTALL, /**< Blackman Nuttall windowed sinc */
176  SWR_FILTER_TYPE_KAISER, /**< Kaiser windowed sinc */
177 };
178 
179 /**
180  * @}
181  */
182 
183 /**
184  * The libswresample context. Unlike libavcodec and libavformat, this structure
185  * is opaque. This means that if you would like to set options, you must use
186  * the @ref avoptions API and cannot directly set values to members of the
187  * structure.
188  */
189 typedef struct SwrContext SwrContext;
190 
191 /**
192  * Get the AVClass for SwrContext. It can be used in combination with
193  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
194  *
195  * @see av_opt_find().
196  * @return the AVClass of SwrContext
197  */
198 const AVClass *swr_get_class(void);
199 
200 /**
201  * @name SwrContext constructor functions
202  * @{
203  */
204 
205 /**
206  * Allocate SwrContext.
207  *
208  * If you use this function you will need to set the parameters (manually or
209  * with swr_alloc_set_opts2()) before calling swr_init().
210  *
211  * @see swr_alloc_set_opts2(), swr_init(), swr_free()
212  * @return NULL on error, allocated context otherwise
213  */
214 struct SwrContext *swr_alloc(void);
215 
216 /**
217  * Initialize context after user parameters have been set.
218  * @note The context must be configured using the AVOption API.
219  *
220  * @see av_opt_set_int()
221  * @see av_opt_set_dict()
222  *
223  * @param[in,out] s Swr context to initialize
224  * @return AVERROR error code in case of failure.
225  */
226 int swr_init(struct SwrContext *s);
227 
228 /**
229  * Check whether an swr context has been initialized or not.
230  *
231  * @param[in] s Swr context to check
232  * @see swr_init()
233  * @return positive if it has been initialized, 0 if not initialized
234  */
235 int swr_is_initialized(struct SwrContext *s);
236 
237 /**
238  * Allocate SwrContext if needed and set/reset common parameters.
239  *
240  * This function does not require *ps to be allocated with swr_alloc(). On the
241  * other hand, swr_alloc() can use swr_alloc_set_opts2() to set the parameters
242  * on the allocated context.
243  *
244  * @param ps Pointer to an existing Swr context if available, or to NULL if not.
245  * On success, *ps will be set to the allocated context.
246  * @param out_ch_layout output channel layout (e.g. AV_CHANNEL_LAYOUT_*)
247  * @param out_sample_fmt output sample format (AV_SAMPLE_FMT_*).
248  * @param out_sample_rate output sample rate (frequency in Hz)
249  * @param in_ch_layout input channel layout (e.g. AV_CHANNEL_LAYOUT_*)
250  * @param in_sample_fmt input sample format (AV_SAMPLE_FMT_*).
251  * @param in_sample_rate input sample rate (frequency in Hz)
252  * @param log_offset logging level offset
253  * @param log_ctx parent logging context, can be NULL
254  *
255  * @see swr_init(), swr_free()
256  * @return 0 on success, a negative AVERROR code on error.
257  * On error, the Swr context is freed and *ps set to NULL.
258  */
259 int swr_alloc_set_opts2(struct SwrContext **ps,
262  int log_offset, void *log_ctx);
263 /**
264  * @}
265  *
266  * @name SwrContext destructor functions
267  * @{
268  */
269 
270 /**
271  * Free the given SwrContext and set the pointer to NULL.
272  *
273  * @param[in] s a pointer to a pointer to Swr context
274  */
275 void swr_free(struct SwrContext **s);
276 
277 /**
278  * Closes the context so that swr_is_initialized() returns 0.
279  *
280  * The context can be brought back to life by running swr_init(),
281  * swr_init() can also be used without swr_close().
282  * This function is mainly provided for simplifying the usecase
283  * where one tries to support libavresample and libswresample.
284  *
285  * @param[in,out] s Swr context to be closed
286  */
287 void swr_close(struct SwrContext *s);
288 
289 /**
290  * @}
291  *
292  * @name Core conversion functions
293  * @{
294  */
295 
296 /** Convert audio.
297  *
298  * in and in_count can be set to 0 to flush the last few samples out at the
299  * end.
300  *
301  * If more input is provided than output space, then the input will be buffered.
302  * You can avoid this buffering by using swr_get_out_samples() to retrieve an
303  * upper bound on the required number of output samples for the given number of
304  * input samples. Conversion will run directly without copying whenever possible.
305  *
306  * @param s allocated Swr context, with parameters set
307  * @param out output buffers, only the first one need be set in case of packed audio
308  * @param out_count amount of space available for output in samples per channel
309  * @param in input buffers, only the first one need to be set in case of packed audio
310  * @param in_count number of input samples available in one channel
311  *
312  * @return number of samples output per channel, negative value on error
313  */
314 int swr_convert(struct SwrContext *s, uint8_t * const *out, int out_count,
315  const uint8_t * const *in , int in_count);
316 
317 /**
318  * Convert the next timestamp from input to output
319  * timestamps are in 1/(in_sample_rate * out_sample_rate) units.
320  *
321  * @note There are 2 slightly differently behaving modes.
322  * @li When automatic timestamp compensation is not used, (min_compensation >= FLT_MAX)
323  * in this case timestamps will be passed through with delays compensated
324  * @li When automatic timestamp compensation is used, (min_compensation < FLT_MAX)
325  * in this case the output timestamps will match output sample numbers.
326  * See ffmpeg-resampler(1) for the two modes of compensation.
327  *
328  * @param[in] s initialized Swr context
329  * @param[in] pts timestamp for the next input sample, INT64_MIN if unknown
330  * @see swr_set_compensation(), swr_drop_output(), and swr_inject_silence() are
331  * function used internally for timestamp compensation.
332  * @return the output timestamp for the next output sample
333  */
334 int64_t swr_next_pts(struct SwrContext *s, int64_t pts);
335 
336 /**
337  * @}
338  *
339  * @name Low-level option setting functions
340  * These functons provide a means to set low-level options that is not possible
341  * with the AVOption API.
342  * @{
343  */
344 
345 /**
346  * Activate resampling compensation ("soft" compensation). This function is
347  * internally called when needed in swr_next_pts().
348  *
349  * @param[in,out] s allocated Swr context. If it is not initialized,
350  * or SWR_FLAG_RESAMPLE is not set, swr_init() is
351  * called with the flag set.
352  * @param[in] sample_delta delta in PTS per sample
353  * @param[in] compensation_distance number of samples to compensate for
354  * @return >= 0 on success, AVERROR error codes if:
355  * @li @c s is NULL,
356  * @li @c compensation_distance is less than 0,
357  * @li @c compensation_distance is 0 but sample_delta is not,
358  * @li compensation unsupported by resampler, or
359  * @li swr_init() fails when called.
360  */
361 int swr_set_compensation(struct SwrContext *s, int sample_delta, int compensation_distance);
362 
363 /**
364  * Set a customized input channel mapping.
365  *
366  * @param[in,out] s allocated Swr context, not yet initialized
367  * @param[in] channel_map customized input channel mapping (array of channel
368  * indexes, -1 for a muted channel)
369  * @return >= 0 on success, or AVERROR error code in case of failure.
370  */
371 int swr_set_channel_mapping(struct SwrContext *s, const int *channel_map);
372 
373 /**
374  * Generate a channel mixing matrix.
375  *
376  * This function is the one used internally by libswresample for building the
377  * default mixing matrix. It is made public just as a utility function for
378  * building custom matrices.
379  *
380  * @param in_layout input channel layout
381  * @param out_layout output channel layout
382  * @param center_mix_level mix level for the center channel
383  * @param surround_mix_level mix level for the surround channel(s)
384  * @param lfe_mix_level mix level for the low-frequency effects channel
385  * @param rematrix_maxval if 1.0, coefficients will be normalized to prevent
386  * overflow. if INT_MAX, coefficients will not be
387  * normalized.
388  * @param[out] matrix mixing coefficients; matrix[i + stride * o] is
389  * the weight of input channel i in output channel o.
390  * @param stride distance between adjacent input channels in the
391  * matrix array
392  * @param matrix_encoding matrixed stereo downmix mode (e.g. dplii)
393  * @param log_ctx parent logging context, can be NULL
394  * @return 0 on success, negative AVERROR code on failure
395  */
396 int swr_build_matrix2(const AVChannelLayout *in_layout, const AVChannelLayout *out_layout,
397  double center_mix_level, double surround_mix_level,
398  double lfe_mix_level, double maxval,
399  double rematrix_volume, double *matrix,
400  ptrdiff_t stride, enum AVMatrixEncoding matrix_encoding,
401  void *log_context);
402 
403 /**
404  * Set a customized remix matrix.
405  *
406  * @param s allocated Swr context, not yet initialized
407  * @param matrix remix coefficients; matrix[i + stride * o] is
408  * the weight of input channel i in output channel o
409  * @param stride offset between lines of the matrix
410  * @return >= 0 on success, or AVERROR error code in case of failure.
411  */
412 int swr_set_matrix(struct SwrContext *s, const double *matrix, int stride);
413 
414 /**
415  * @}
416  *
417  * @name Sample handling functions
418  * @{
419  */
420 
421 /**
422  * Drops the specified number of output samples.
423  *
424  * This function, along with swr_inject_silence(), is called by swr_next_pts()
425  * if needed for "hard" compensation.
426  *
427  * @param s allocated Swr context
428  * @param count number of samples to be dropped
429  *
430  * @return >= 0 on success, or a negative AVERROR code on failure
431  */
432 int swr_drop_output(struct SwrContext *s, int count);
433 
434 /**
435  * Injects the specified number of silence samples.
436  *
437  * This function, along with swr_drop_output(), is called by swr_next_pts()
438  * if needed for "hard" compensation.
439  *
440  * @param s allocated Swr context
441  * @param count number of samples to be dropped
442  *
443  * @return >= 0 on success, or a negative AVERROR code on failure
444  */
445 int swr_inject_silence(struct SwrContext *s, int count);
446 
447 /**
448  * Gets the delay the next input sample will experience relative to the next output sample.
449  *
450  * Swresample can buffer data if more input has been provided than available
451  * output space, also converting between sample rates needs a delay.
452  * This function returns the sum of all such delays.
453  * The exact delay is not necessarily an integer value in either input or
454  * output sample rate. Especially when downsampling by a large value, the
455  * output sample rate may be a poor choice to represent the delay, similarly
456  * for upsampling and the input sample rate.
457  *
458  * @param s swr context
459  * @param base timebase in which the returned delay will be:
460  * @li if it's set to 1 the returned delay is in seconds
461  * @li if it's set to 1000 the returned delay is in milliseconds
462  * @li if it's set to the input sample rate then the returned
463  * delay is in input samples
464  * @li if it's set to the output sample rate then the returned
465  * delay is in output samples
466  * @li if it's the least common multiple of in_sample_rate and
467  * out_sample_rate then an exact rounding-free delay will be
468  * returned
469  * @returns the delay in 1 / @c base units.
470  */
471 int64_t swr_get_delay(struct SwrContext *s, int64_t base);
472 
473 /**
474  * Find an upper bound on the number of samples that the next swr_convert
475  * call will output, if called with in_samples of input samples. This
476  * depends on the internal state, and anything changing the internal state
477  * (like further swr_convert() calls) will may change the number of samples
478  * swr_get_out_samples() returns for the same number of input samples.
479  *
480  * @param in_samples number of input samples.
481  * @note any call to swr_inject_silence(), swr_convert(), swr_next_pts()
482  * or swr_set_compensation() invalidates this limit
483  * @note it is recommended to pass the correct available buffer size
484  * to all functions like swr_convert() even if swr_get_out_samples()
485  * indicates that less would be used.
486  * @returns an upper bound on the number of samples that the next swr_convert
487  * will output or a negative value to indicate an error
488  */
489 int swr_get_out_samples(struct SwrContext *s, int in_samples);
490 
491 /**
492  * @}
493  *
494  * @name Configuration accessors
495  * @{
496  */
497 
498 /**
499  * Return the @ref LIBSWRESAMPLE_VERSION_INT constant.
500  *
501  * This is useful to check if the build-time libswresample has the same version
502  * as the run-time one.
503  *
504  * @returns the unsigned int-typed version
505  */
506 unsigned swresample_version(void);
507 
508 /**
509  * Return the swr build-time configuration.
510  *
511  * @returns the build-time @c ./configure flags
512  */
513 const char *swresample_configuration(void);
514 
515 /**
516  * Return the swr license.
517  *
518  * @returns the license of libswresample, determined at build-time
519  */
520 const char *swresample_license(void);
521 
522 /**
523  * @}
524  *
525  * @name AVFrame based API
526  * @{
527  */
528 
529 /**
530  * Convert the samples in the input AVFrame and write them to the output AVFrame.
531  *
532  * Input and output AVFrames must have channel_layout, sample_rate and format set.
533  *
534  * If the output AVFrame does not have the data pointers allocated the nb_samples
535  * field will be set using av_frame_get_buffer()
536  * is called to allocate the frame.
537  *
538  * The output AVFrame can be NULL or have fewer allocated samples than required.
539  * In this case, any remaining samples not written to the output will be added
540  * to an internal FIFO buffer, to be returned at the next call to this function
541  * or to swr_convert().
542  *
543  * If converting sample rate, there may be data remaining in the internal
544  * resampling delay buffer. swr_get_delay() tells the number of
545  * remaining samples. To get this data as output, call this function or
546  * swr_convert() with NULL input.
547  *
548  * If the SwrContext configuration does not match the output and
549  * input AVFrame settings the conversion does not take place and depending on
550  * which AVFrame is not matching AVERROR_OUTPUT_CHANGED, AVERROR_INPUT_CHANGED
551  * or the result of a bitwise-OR of them is returned.
552  *
553  * @see swr_delay()
554  * @see swr_convert()
555  * @see swr_get_delay()
556  *
557  * @param swr audio resample context
558  * @param output output AVFrame
559  * @param input input AVFrame
560  * @return 0 on success, AVERROR on failure or nonmatching
561  * configuration.
562  */
564  AVFrame *output, const AVFrame *input);
565 
566 /**
567  * Configure or reconfigure the SwrContext using the information
568  * provided by the AVFrames.
569  *
570  * The original resampling context is reset even on failure.
571  * The function calls swr_close() internally if the context is open.
572  *
573  * @see swr_close();
574  *
575  * @param swr audio resample context
576  * @param out output AVFrame
577  * @param in input AVFrame
578  * @return 0 on success, AVERROR on failure.
579  */
580 int swr_config_frame(SwrContext *swr, const AVFrame *out, const AVFrame *in);
581 
582 /**
583  * @}
584  * @}
585  */
586 
587 #endif /* SWRESAMPLE_SWRESAMPLE_H */
SWR_DITHER_TRIANGULAR_HIGHPASS
@ SWR_DITHER_TRIANGULAR_HIGHPASS
Definition: swresample.h:152
SWR_DITHER_NS_LOW_SHIBATA
@ SWR_DITHER_NS_LOW_SHIBATA
Definition: swresample.h:160
out
FILE * out
Definition: movenc.c:55
SwrContext::in_sample_rate
int in_sample_rate
input sample rate
Definition: swresample_internal.h:105
SWR_DITHER_NS_IMPROVED_E_WEIGHTED
@ SWR_DITHER_NS_IMPROVED_E_WEIGHTED
Definition: swresample.h:158
matrix
Definition: vc1dsp.c:43
swr_set_compensation
int swr_set_compensation(struct SwrContext *s, int sample_delta, int compensation_distance)
Activate resampling compensation ("soft" compensation).
Definition: swresample.c:904
SWR_DITHER_NS_MODIFIED_E_WEIGHTED
@ SWR_DITHER_NS_MODIFIED_E_WEIGHTED
Definition: swresample.h:157
output
filter_frame For filters that do not use the this method is called when a frame is pushed to the filter s input It can be called at any time except in a reentrant way If the input frame is enough to produce output
Definition: filter_design.txt:225
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:374
SwrDitherType
SwrDitherType
Dithering algorithms.
Definition: swresample.h:148
SwrContext::out_sample_rate
int out_sample_rate
output sample rate
Definition: swresample_internal.h:106
SwrContext::out_ch_layout
AVChannelLayout out_ch_layout
output channel layout
Definition: swresample_internal.h:104
base
uint8_t base
Definition: vp3data.h:128
swr_set_channel_mapping
int swr_set_channel_mapping(struct SwrContext *s, const int *channel_map)
Set a customized input channel mapping.
Definition: swresample.c:33
SwrContext::matrix_encoding
int matrix_encoding
matrixed stereo encoding
Definition: swresample_internal.h:113
swr_set_matrix
int swr_set_matrix(struct SwrContext *s, const double *matrix, int stride)
Set a customized remix matrix.
Definition: rematrix.c:65
SWR_ENGINE_SOXR
@ SWR_ENGINE_SOXR
SoX Resampler.
Definition: swresample.h:168
SWR_FILTER_TYPE_BLACKMAN_NUTTALL
@ SWR_FILTER_TYPE_BLACKMAN_NUTTALL
Blackman Nuttall windowed sinc.
Definition: swresample.h:175
SwrContext::out_sample_fmt
enum AVSampleFormat out_sample_fmt
output sample format
Definition: swresample_internal.h:101
swr_is_initialized
int swr_is_initialized(struct SwrContext *s)
Check whether an swr context has been initialized or not.
Definition: swresample.c:715
samplefmt.h
pts
static int64_t pts
Definition: transcode_aac.c:644
SWR_FILTER_TYPE_KAISER
@ SWR_FILTER_TYPE_KAISER
Kaiser windowed sinc.
Definition: swresample.h:176
swr_next_pts
int64_t swr_next_pts(struct SwrContext *s, int64_t pts)
Convert the next timestamp from input to output timestamps are in 1/(in_sample_rate * out_sample_rate...
Definition: swresample.c:924
swr_convert
int swr_convert(struct SwrContext *s, uint8_t *const *out, int out_count, const uint8_t *const *in, int in_count)
Convert audio.
Definition: swresample.c:719
swr_get_delay
int64_t swr_get_delay(struct SwrContext *s, int64_t base)
Gets the delay the next input sample will experience relative to the next output sample.
Definition: swresample.c:874
SWR_DITHER_NB
@ SWR_DITHER_NB
not part of API/ABI
Definition: swresample.h:162
swr_inject_silence
int swr_inject_silence(struct SwrContext *s, int count)
Injects the specified number of silence samples.
Definition: swresample.c:846
swr_init
int swr_init(struct SwrContext *s)
Initialize context after user parameters have been set.
Definition: swresample.c:140
SwrContext::lfe_mix_level
float lfe_mix_level
LFE mixing level.
Definition: swresample_internal.h:110
s
#define s(width, name)
Definition: cbs_vp9.c:198
swr_alloc
struct SwrContext * swr_alloc(void)
Allocate SwrContext.
Definition: options.c:148
SWR_DITHER_NS
@ SWR_DITHER_NS
not part of API/ABI
Definition: swresample.h:154
channel_map
static const uint8_t channel_map[8][8]
Definition: atrac3plusdec.c:52
SWR_ENGINE_NB
@ SWR_ENGINE_NB
not part of API/ABI
Definition: swresample.h:169
SwrContext
The libswresample context.
Definition: swresample_internal.h:95
swr_build_matrix2
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)
Generate a channel mixing matrix.
Definition: rematrix.c:127
SwrContext::in_ch_layout
AVChannelLayout in_ch_layout
input channel layout
Definition: swresample_internal.h:103
AVMatrixEncoding
AVMatrixEncoding
Definition: channel_layout.h:252
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
SwrFilterType
SwrFilterType
Resampling Filter Types.
Definition: swresample.h:173
swr_get_class
const AVClass * swr_get_class(void)
Get the AVClass for SwrContext.
Definition: options.c:143
swresample_license
const char * swresample_license(void)
Return the swr license.
Definition: version.c:41
SwrContext::log_ctx
void * log_ctx
parent logging context
Definition: swresample_internal.h:98
version_major.h
SWR_DITHER_NONE
@ SWR_DITHER_NONE
Definition: swresample.h:149
SWR_DITHER_TRIANGULAR
@ SWR_DITHER_TRIANGULAR
Definition: swresample.h:151
swr_alloc_set_opts2
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)
Allocate SwrContext if needed and set/reset common parameters.
Definition: swresample.c:40
swr_convert_frame
int swr_convert_frame(SwrContext *swr, AVFrame *output, const AVFrame *input)
Convert the samples in the input AVFrame and write them to the output AVFrame.
Definition: swresample_frame.c:139
AVChannelLayout
An AVChannelLayout holds information about the channel layout of audio data.
Definition: channel_layout.h:311
swr_drop_output
int swr_drop_output(struct SwrContext *s, int count)
Drops the specified number of output samples.
Definition: swresample.c:835
SWR_FILTER_TYPE_CUBIC
@ SWR_FILTER_TYPE_CUBIC
Cubic.
Definition: swresample.h:174
swr_free
void swr_free(struct SwrContext **s)
Free the given SwrContext and set the pointer to NULL.
Definition: swresample.c:121
frame.h
SWR_ENGINE_SWR
@ SWR_ENGINE_SWR
SW Resampler.
Definition: swresample.h:167
input
and forward the test the status of outputs and forward it to the corresponding return FFERROR_NOT_READY If the filters stores internally one or a few frame for some input
Definition: filter_design.txt:172
SwrEngine
SwrEngine
Resampling Engines.
Definition: swresample.h:166
swr_config_frame
int swr_config_frame(SwrContext *swr, const AVFrame *out, const AVFrame *in)
Configure or reconfigure the SwrContext using the information provided by the AVFrames.
Definition: swresample_frame.c:27
AVSampleFormat
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:55
stride
#define stride
Definition: h264pred_template.c:537
SwrContext::rematrix_volume
float rematrix_volume
rematrixing volume coefficient
Definition: swresample_internal.h:111
SwrContext::in_sample_fmt
enum AVSampleFormat in_sample_fmt
input sample format
Definition: swresample_internal.h:99
channel_layout.h
SWR_DITHER_NS_SHIBATA
@ SWR_DITHER_NS_SHIBATA
Definition: swresample.h:159
SWR_DITHER_NS_HIGH_SHIBATA
@ SWR_DITHER_NS_HIGH_SHIBATA
Definition: swresample.h:161
swr_get_out_samples
int swr_get_out_samples(struct SwrContext *s, int in_samples)
Find an upper bound on the number of samples that the next swr_convert call will output,...
Definition: swresample.c:882
SwrContext::in
AudioData in
input audio data
Definition: swresample_internal.h:146
SWR_DITHER_NS_LIPSHITZ
@ SWR_DITHER_NS_LIPSHITZ
Definition: swresample.h:155
swr_close
void swr_close(struct SwrContext *s)
Closes the context so that swr_is_initialized() returns 0.
Definition: swresample.c:136
swresample_configuration
const char * swresample_configuration(void)
Return the swr build-time configuration.
Definition: version.c:36
SWR_DITHER_NS_F_WEIGHTED
@ SWR_DITHER_NS_F_WEIGHTED
Definition: swresample.h:156
version.h
swresample_version
unsigned swresample_version(void)
Return the LIBSWRESAMPLE_VERSION_INT constant.
Definition: version.c:30
SWR_DITHER_RECTANGULAR
@ SWR_DITHER_RECTANGULAR
Definition: swresample.h:150