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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 #if FF_API_OLD_CHANNEL_LAYOUT
238 /**
239  * Allocate SwrContext if needed and set/reset common parameters.
240  *
241  * This function does not require s to be allocated with swr_alloc(). On the
242  * other hand, swr_alloc() can use swr_alloc_set_opts() to set the parameters
243  * on the allocated context.
244  *
245  * @param s existing Swr context if available, or NULL if not
246  * @param out_ch_layout output channel layout (AV_CH_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 (AV_CH_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 NULL on error, allocated context otherwise
257  * @deprecated use @ref swr_alloc_set_opts2()
258  */
260 struct SwrContext *swr_alloc_set_opts(struct SwrContext *s,
263  int log_offset, void *log_ctx);
264 #endif
265 
266 /**
267  * Allocate SwrContext if needed and set/reset common parameters.
268  *
269  * This function does not require *ps to be allocated with swr_alloc(). On the
270  * other hand, swr_alloc() can use swr_alloc_set_opts2() to set the parameters
271  * on the allocated context.
272  *
273  * @param ps Pointer to an existing Swr context if available, or to NULL if not.
274  * On success, *ps will be set to the allocated context.
275  * @param out_ch_layout output channel layout (e.g. AV_CHANNEL_LAYOUT_*)
276  * @param out_sample_fmt output sample format (AV_SAMPLE_FMT_*).
277  * @param out_sample_rate output sample rate (frequency in Hz)
278  * @param in_ch_layout input channel layout (e.g. AV_CHANNEL_LAYOUT_*)
279  * @param in_sample_fmt input sample format (AV_SAMPLE_FMT_*).
280  * @param in_sample_rate input sample rate (frequency in Hz)
281  * @param log_offset logging level offset
282  * @param log_ctx parent logging context, can be NULL
283  *
284  * @see swr_init(), swr_free()
285  * @return 0 on success, a negative AVERROR code on error.
286  * On error, the Swr context is freed and *ps set to NULL.
287  */
288 int swr_alloc_set_opts2(struct SwrContext **ps,
291  int log_offset, void *log_ctx);
292 /**
293  * @}
294  *
295  * @name SwrContext destructor functions
296  * @{
297  */
298 
299 /**
300  * Free the given SwrContext and set the pointer to NULL.
301  *
302  * @param[in] s a pointer to a pointer to Swr context
303  */
304 void swr_free(struct SwrContext **s);
305 
306 /**
307  * Closes the context so that swr_is_initialized() returns 0.
308  *
309  * The context can be brought back to life by running swr_init(),
310  * swr_init() can also be used without swr_close().
311  * This function is mainly provided for simplifying the usecase
312  * where one tries to support libavresample and libswresample.
313  *
314  * @param[in,out] s Swr context to be closed
315  */
316 void swr_close(struct SwrContext *s);
317 
318 /**
319  * @}
320  *
321  * @name Core conversion functions
322  * @{
323  */
324 
325 /** Convert audio.
326  *
327  * in and in_count can be set to 0 to flush the last few samples out at the
328  * end.
329  *
330  * If more input is provided than output space, then the input will be buffered.
331  * You can avoid this buffering by using swr_get_out_samples() to retrieve an
332  * upper bound on the required number of output samples for the given number of
333  * input samples. Conversion will run directly without copying whenever possible.
334  *
335  * @param s allocated Swr context, with parameters set
336  * @param out output buffers, only the first one need be set in case of packed audio
337  * @param out_count amount of space available for output in samples per channel
338  * @param in input buffers, only the first one need to be set in case of packed audio
339  * @param in_count number of input samples available in one channel
340  *
341  * @return number of samples output per channel, negative value on error
342  */
343 int swr_convert(struct SwrContext *s, uint8_t **out, int out_count,
344  const uint8_t **in , int in_count);
345 
346 /**
347  * Convert the next timestamp from input to output
348  * timestamps are in 1/(in_sample_rate * out_sample_rate) units.
349  *
350  * @note There are 2 slightly differently behaving modes.
351  * @li When automatic timestamp compensation is not used, (min_compensation >= FLT_MAX)
352  * in this case timestamps will be passed through with delays compensated
353  * @li When automatic timestamp compensation is used, (min_compensation < FLT_MAX)
354  * in this case the output timestamps will match output sample numbers.
355  * See ffmpeg-resampler(1) for the two modes of compensation.
356  *
357  * @param[in] s initialized Swr context
358  * @param[in] pts timestamp for the next input sample, INT64_MIN if unknown
359  * @see swr_set_compensation(), swr_drop_output(), and swr_inject_silence() are
360  * function used internally for timestamp compensation.
361  * @return the output timestamp for the next output sample
362  */
363 int64_t swr_next_pts(struct SwrContext *s, int64_t pts);
364 
365 /**
366  * @}
367  *
368  * @name Low-level option setting functions
369  * These functons provide a means to set low-level options that is not possible
370  * with the AVOption API.
371  * @{
372  */
373 
374 /**
375  * Activate resampling compensation ("soft" compensation). This function is
376  * internally called when needed in swr_next_pts().
377  *
378  * @param[in,out] s allocated Swr context. If it is not initialized,
379  * or SWR_FLAG_RESAMPLE is not set, swr_init() is
380  * called with the flag set.
381  * @param[in] sample_delta delta in PTS per sample
382  * @param[in] compensation_distance number of samples to compensate for
383  * @return >= 0 on success, AVERROR error codes if:
384  * @li @c s is NULL,
385  * @li @c compensation_distance is less than 0,
386  * @li @c compensation_distance is 0 but sample_delta is not,
387  * @li compensation unsupported by resampler, or
388  * @li swr_init() fails when called.
389  */
390 int swr_set_compensation(struct SwrContext *s, int sample_delta, int compensation_distance);
391 
392 /**
393  * Set a customized input channel mapping.
394  *
395  * @param[in,out] s allocated Swr context, not yet initialized
396  * @param[in] channel_map customized input channel mapping (array of channel
397  * indexes, -1 for a muted channel)
398  * @return >= 0 on success, or AVERROR error code in case of failure.
399  */
400 int swr_set_channel_mapping(struct SwrContext *s, const int *channel_map);
401 
402 #if FF_API_OLD_CHANNEL_LAYOUT
403 /**
404  * Generate a channel mixing matrix.
405  *
406  * This function is the one used internally by libswresample for building the
407  * default mixing matrix. It is made public just as a utility function for
408  * building custom matrices.
409  *
410  * @param in_layout input channel layout
411  * @param out_layout output channel layout
412  * @param center_mix_level mix level for the center channel
413  * @param surround_mix_level mix level for the surround channel(s)
414  * @param lfe_mix_level mix level for the low-frequency effects channel
415  * @param rematrix_maxval if 1.0, coefficients will be normalized to prevent
416  * overflow. if INT_MAX, coefficients will not be
417  * normalized.
418  * @param[out] matrix mixing coefficients; matrix[i + stride * o] is
419  * the weight of input channel i in output channel o.
420  * @param stride distance between adjacent input channels in the
421  * matrix array
422  * @param matrix_encoding matrixed stereo downmix mode (e.g. dplii)
423  * @param log_ctx parent logging context, can be NULL
424  * @return 0 on success, negative AVERROR code on failure
425  * @deprecated use @ref swr_build_matrix2()
426  */
428 int swr_build_matrix(uint64_t in_layout, uint64_t out_layout,
429  double center_mix_level, double surround_mix_level,
430  double lfe_mix_level, double rematrix_maxval,
431  double rematrix_volume, double *matrix,
433  void *log_ctx);
434 #endif
435 
436 /**
437  * Generate a channel mixing matrix.
438  *
439  * This function is the one used internally by libswresample for building the
440  * default mixing matrix. It is made public just as a utility function for
441  * building custom matrices.
442  *
443  * @param in_layout input channel layout
444  * @param out_layout output channel layout
445  * @param center_mix_level mix level for the center channel
446  * @param surround_mix_level mix level for the surround channel(s)
447  * @param lfe_mix_level mix level for the low-frequency effects channel
448  * @param rematrix_maxval if 1.0, coefficients will be normalized to prevent
449  * overflow. if INT_MAX, coefficients will not be
450  * normalized.
451  * @param[out] matrix mixing coefficients; matrix[i + stride * o] is
452  * the weight of input channel i in output channel o.
453  * @param stride distance between adjacent input channels in the
454  * matrix array
455  * @param matrix_encoding matrixed stereo downmix mode (e.g. dplii)
456  * @param log_ctx parent logging context, can be NULL
457  * @return 0 on success, negative AVERROR code on failure
458  */
459 int swr_build_matrix2(const AVChannelLayout *in_layout, const AVChannelLayout *out_layout,
460  double center_mix_level, double surround_mix_level,
461  double lfe_mix_level, double maxval,
462  double rematrix_volume, double *matrix,
463  ptrdiff_t stride, enum AVMatrixEncoding matrix_encoding,
464  void *log_context);
465 
466 /**
467  * Set a customized remix matrix.
468  *
469  * @param s allocated Swr context, not yet initialized
470  * @param matrix remix coefficients; matrix[i + stride * o] is
471  * the weight of input channel i in output channel o
472  * @param stride offset between lines of the matrix
473  * @return >= 0 on success, or AVERROR error code in case of failure.
474  */
475 int swr_set_matrix(struct SwrContext *s, const double *matrix, int stride);
476 
477 /**
478  * @}
479  *
480  * @name Sample handling functions
481  * @{
482  */
483 
484 /**
485  * Drops the specified number of output samples.
486  *
487  * This function, along with swr_inject_silence(), is called by swr_next_pts()
488  * if needed for "hard" compensation.
489  *
490  * @param s allocated Swr context
491  * @param count number of samples to be dropped
492  *
493  * @return >= 0 on success, or a negative AVERROR code on failure
494  */
495 int swr_drop_output(struct SwrContext *s, int count);
496 
497 /**
498  * Injects the specified number of silence samples.
499  *
500  * This function, along with swr_drop_output(), is called by swr_next_pts()
501  * if needed for "hard" compensation.
502  *
503  * @param s allocated Swr context
504  * @param count number of samples to be dropped
505  *
506  * @return >= 0 on success, or a negative AVERROR code on failure
507  */
508 int swr_inject_silence(struct SwrContext *s, int count);
509 
510 /**
511  * Gets the delay the next input sample will experience relative to the next output sample.
512  *
513  * Swresample can buffer data if more input has been provided than available
514  * output space, also converting between sample rates needs a delay.
515  * This function returns the sum of all such delays.
516  * The exact delay is not necessarily an integer value in either input or
517  * output sample rate. Especially when downsampling by a large value, the
518  * output sample rate may be a poor choice to represent the delay, similarly
519  * for upsampling and the input sample rate.
520  *
521  * @param s swr context
522  * @param base timebase in which the returned delay will be:
523  * @li if it's set to 1 the returned delay is in seconds
524  * @li if it's set to 1000 the returned delay is in milliseconds
525  * @li if it's set to the input sample rate then the returned
526  * delay is in input samples
527  * @li if it's set to the output sample rate then the returned
528  * delay is in output samples
529  * @li if it's the least common multiple of in_sample_rate and
530  * out_sample_rate then an exact rounding-free delay will be
531  * returned
532  * @returns the delay in 1 / @c base units.
533  */
534 int64_t swr_get_delay(struct SwrContext *s, int64_t base);
535 
536 /**
537  * Find an upper bound on the number of samples that the next swr_convert
538  * call will output, if called with in_samples of input samples. This
539  * depends on the internal state, and anything changing the internal state
540  * (like further swr_convert() calls) will may change the number of samples
541  * swr_get_out_samples() returns for the same number of input samples.
542  *
543  * @param in_samples number of input samples.
544  * @note any call to swr_inject_silence(), swr_convert(), swr_next_pts()
545  * or swr_set_compensation() invalidates this limit
546  * @note it is recommended to pass the correct available buffer size
547  * to all functions like swr_convert() even if swr_get_out_samples()
548  * indicates that less would be used.
549  * @returns an upper bound on the number of samples that the next swr_convert
550  * will output or a negative value to indicate an error
551  */
552 int swr_get_out_samples(struct SwrContext *s, int in_samples);
553 
554 /**
555  * @}
556  *
557  * @name Configuration accessors
558  * @{
559  */
560 
561 /**
562  * Return the @ref LIBSWRESAMPLE_VERSION_INT constant.
563  *
564  * This is useful to check if the build-time libswresample has the same version
565  * as the run-time one.
566  *
567  * @returns the unsigned int-typed version
568  */
569 unsigned swresample_version(void);
570 
571 /**
572  * Return the swr build-time configuration.
573  *
574  * @returns the build-time @c ./configure flags
575  */
576 const char *swresample_configuration(void);
577 
578 /**
579  * Return the swr license.
580  *
581  * @returns the license of libswresample, determined at build-time
582  */
583 const char *swresample_license(void);
584 
585 /**
586  * @}
587  *
588  * @name AVFrame based API
589  * @{
590  */
591 
592 /**
593  * Convert the samples in the input AVFrame and write them to the output AVFrame.
594  *
595  * Input and output AVFrames must have channel_layout, sample_rate and format set.
596  *
597  * If the output AVFrame does not have the data pointers allocated the nb_samples
598  * field will be set using av_frame_get_buffer()
599  * is called to allocate the frame.
600  *
601  * The output AVFrame can be NULL or have fewer allocated samples than required.
602  * In this case, any remaining samples not written to the output will be added
603  * to an internal FIFO buffer, to be returned at the next call to this function
604  * or to swr_convert().
605  *
606  * If converting sample rate, there may be data remaining in the internal
607  * resampling delay buffer. swr_get_delay() tells the number of
608  * remaining samples. To get this data as output, call this function or
609  * swr_convert() with NULL input.
610  *
611  * If the SwrContext configuration does not match the output and
612  * input AVFrame settings the conversion does not take place and depending on
613  * which AVFrame is not matching AVERROR_OUTPUT_CHANGED, AVERROR_INPUT_CHANGED
614  * or the result of a bitwise-OR of them is returned.
615  *
616  * @see swr_delay()
617  * @see swr_convert()
618  * @see swr_get_delay()
619  *
620  * @param swr audio resample context
621  * @param output output AVFrame
622  * @param input input AVFrame
623  * @return 0 on success, AVERROR on failure or nonmatching
624  * configuration.
625  */
627  AVFrame *output, const AVFrame *input);
628 
629 /**
630  * Configure or reconfigure the SwrContext using the information
631  * provided by the AVFrames.
632  *
633  * The original resampling context is reset even on failure.
634  * The function calls swr_close() internally if the context is open.
635  *
636  * @see swr_close();
637  *
638  * @param swr audio resample context
639  * @param out output AVFrame
640  * @param in input AVFrame
641  * @return 0 on success, AVERROR on failure.
642  */
643 int swr_config_frame(SwrContext *swr, const AVFrame *out, const AVFrame *in);
644 
645 /**
646  * @}
647  * @}
648  */
649 
650 #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:54
SwrContext::in_sample_rate
int in_sample_rate
input sample rate
Definition: swresample_internal.h:104
SWR_DITHER_NS_IMPROVED_E_WEIGHTED
@ SWR_DITHER_NS_IMPROVED_E_WEIGHTED
Definition: swresample.h:158
matrix
Definition: vc1dsp.c:42
swr_set_compensation
int swr_set_compensation(struct SwrContext *s, int sample_delta, int compensation_distance)
Activate resampling compensation ("soft" compensation).
Definition: swresample.c:1001
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:325
SwrDitherType
SwrDitherType
Dithering algorithms.
Definition: swresample.h:148
SwrContext::out_sample_rate
int out_sample_rate
output sample rate
Definition: swresample_internal.h:105
SwrContext::out_ch_layout
AVChannelLayout out_ch_layout
output channel layout
Definition: swresample_internal.h:103
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:32
SwrContext::matrix_encoding
int matrix_encoding
matrixed stereo encoding
Definition: swresample_internal.h:112
swr_set_matrix
int swr_set_matrix(struct SwrContext *s, const double *matrix, int stride)
Set a customized remix matrix.
Definition: rematrix.c:64
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:812
samplefmt.h
pts
static int64_t pts
Definition: transcode_aac.c:654
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:1021
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:971
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:943
swr_init
int swr_init(struct SwrContext *s)
Initialize context after user parameters have been set.
Definition: swresample.c:191
SwrContext::lfe_mix_level
float lfe_mix_level
LFE mixing level.
Definition: swresample_internal.h:109
s
#define s(width, name)
Definition: cbs_vp9.c:256
swr_alloc
struct SwrContext * swr_alloc(void)
Allocate SwrContext.
Definition: options.c:167
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:51
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:170
SwrContext::in_ch_layout
AVChannelLayout in_ch_layout
input channel layout
Definition: swresample_internal.h:102
AVMatrixEncoding
AVMatrixEncoding
Definition: channel_layout.h:242
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:162
swresample_license
const char * swresample_license(void)
Return the swr license.
Definition: version.c:40
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:85
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:184
AVChannelLayout
An AVChannelLayout holds information about the channel layout of audio data.
Definition: channel_layout.h:301
swr_drop_output
int swr_drop_output(struct SwrContext *s, int count)
Drops the specified number of output samples.
Definition: swresample.c:932
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:173
swr_convert
int swr_convert(struct SwrContext *s, uint8_t **out, int out_count, const uint8_t **in, int in_count)
Convert audio.
Definition: swresample.c:816
frame.h
attribute_deprecated
#define attribute_deprecated
Definition: attributes.h:104
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:110
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
SwrContext::rematrix_maxval
float rematrix_maxval
maximum value for rematrixing output
Definition: swresample_internal.h:111
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:979
SwrContext::in
AudioData in
input audio data
Definition: swresample_internal.h:152
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:187
swresample_configuration
const char * swresample_configuration(void)
Return the swr build-time configuration.
Definition: version.c:35
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:29
SWR_DITHER_RECTANGULAR
@ SWR_DITHER_RECTANGULAR
Definition: swresample.h:150