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1 | /* |
2 | * Copyright (c) 2012 Justin Ruggles <justin.ruggles@gmail.com> | |
3 | * | |
4 | * This file is part of FFmpeg. | |
5 | * | |
6 | * FFmpeg 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 | * FFmpeg 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 FFmpeg; if not, write to the Free Software | |
18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
19 | */ | |
20 | ||
21 | #ifndef AVRESAMPLE_AVRESAMPLE_H | |
22 | #define AVRESAMPLE_AVRESAMPLE_H | |
23 | ||
24 | /** | |
25 | * @file | |
26 | * @ingroup lavr | |
27 | * external API header | |
28 | */ | |
29 | ||
30 | /** | |
31 | * @defgroup lavr Libavresample | |
32 | * @{ | |
33 | * | |
34 | * Libavresample (lavr) is a library that handles audio resampling, sample | |
35 | * format conversion and mixing. | |
36 | * | |
37 | * Interaction with lavr is done through AVAudioResampleContext, which is | |
38 | * allocated with avresample_alloc_context(). It is opaque, so all parameters | |
39 | * must be set with the @ref avoptions API. | |
40 | * | |
41 | * For example the following code will setup conversion from planar float sample | |
42 | * format to interleaved signed 16-bit integer, downsampling from 48kHz to | |
43 | * 44.1kHz and downmixing from 5.1 channels to stereo (using the default mixing | |
44 | * matrix): | |
45 | * @code | |
46 | * AVAudioResampleContext *avr = avresample_alloc_context(); | |
47 | * av_opt_set_int(avr, "in_channel_layout", AV_CH_LAYOUT_5POINT1, 0); | |
48 | * av_opt_set_int(avr, "out_channel_layout", AV_CH_LAYOUT_STEREO, 0); | |
49 | * av_opt_set_int(avr, "in_sample_rate", 48000, 0); | |
50 | * av_opt_set_int(avr, "out_sample_rate", 44100, 0); | |
51 | * av_opt_set_int(avr, "in_sample_fmt", AV_SAMPLE_FMT_FLTP, 0); | |
52 | * av_opt_set_int(avr, "out_sample_fmt", AV_SAMPLE_FMT_S16, 0); | |
53 | * @endcode | |
54 | * | |
55 | * Once the context is initialized, it must be opened with avresample_open(). If | |
56 | * you need to change the conversion parameters, you must close the context with | |
57 | * avresample_close(), change the parameters as described above, then reopen it | |
58 | * again. | |
59 | * | |
60 | * The conversion itself is done by repeatedly calling avresample_convert(). | |
61 | * Note that the samples may get buffered in two places in lavr. The first one | |
62 | * is the output FIFO, where the samples end up if the output buffer is not | |
63 | * large enough. The data stored in there may be retrieved at any time with | |
64 | * avresample_read(). The second place is the resampling delay buffer, | |
65 | * applicable only when resampling is done. The samples in it require more input | |
66 | * before they can be processed. Their current amount is returned by | |
67 | * avresample_get_delay(). At the end of conversion the resampling buffer can be | |
68 | * flushed by calling avresample_convert() with NULL input. | |
69 | * | |
70 | * The following code demonstrates the conversion loop assuming the parameters | |
71 | * from above and caller-defined functions get_input() and handle_output(): | |
72 | * @code | |
73 | * uint8_t **input; | |
74 | * int in_linesize, in_samples; | |
75 | * | |
76 | * while (get_input(&input, &in_linesize, &in_samples)) { | |
77 | * uint8_t *output | |
78 | * int out_linesize; | |
79 | * int out_samples = avresample_get_out_samples(avr, in_samples); | |
80 | * | |
81 | * av_samples_alloc(&output, &out_linesize, 2, out_samples, | |
82 | * AV_SAMPLE_FMT_S16, 0); | |
83 | * out_samples = avresample_convert(avr, &output, out_linesize, out_samples, | |
84 | * input, in_linesize, in_samples); | |
85 | * handle_output(output, out_linesize, out_samples); | |
86 | * av_freep(&output); | |
87 | * } | |
88 | * @endcode | |
89 | * | |
90 | * When the conversion is finished and the FIFOs are flushed if required, the | |
91 | * conversion context and everything associated with it must be freed with | |
92 | * avresample_free(). | |
93 | */ | |
94 | ||
95 | #include "libavutil/avutil.h" | |
96 | #include "libavutil/channel_layout.h" | |
97 | #include "libavutil/dict.h" | |
98 | #include "libavutil/frame.h" | |
99 | #include "libavutil/log.h" | |
100 | #include "libavutil/mathematics.h" | |
101 | ||
102 | #include "libavresample/version.h" | |
103 | ||
104 | #define AVRESAMPLE_MAX_CHANNELS 32 | |
105 | ||
106 | typedef struct AVAudioResampleContext AVAudioResampleContext; | |
107 | ||
108 | /** Mixing Coefficient Types */ | |
109 | enum AVMixCoeffType { | |
110 | AV_MIX_COEFF_TYPE_Q8, /** 16-bit 8.8 fixed-point */ | |
111 | AV_MIX_COEFF_TYPE_Q15, /** 32-bit 17.15 fixed-point */ | |
112 | AV_MIX_COEFF_TYPE_FLT, /** floating-point */ | |
113 | AV_MIX_COEFF_TYPE_NB, /** Number of coeff types. Not part of ABI */ | |
114 | }; | |
115 | ||
116 | /** Resampling Filter Types */ | |
117 | enum AVResampleFilterType { | |
118 | AV_RESAMPLE_FILTER_TYPE_CUBIC, /**< Cubic */ | |
119 | AV_RESAMPLE_FILTER_TYPE_BLACKMAN_NUTTALL, /**< Blackman Nuttall Windowed Sinc */ | |
120 | AV_RESAMPLE_FILTER_TYPE_KAISER, /**< Kaiser Windowed Sinc */ | |
121 | }; | |
122 | ||
123 | enum AVResampleDitherMethod { | |
124 | AV_RESAMPLE_DITHER_NONE, /**< Do not use dithering */ | |
125 | AV_RESAMPLE_DITHER_RECTANGULAR, /**< Rectangular Dither */ | |
126 | AV_RESAMPLE_DITHER_TRIANGULAR, /**< Triangular Dither*/ | |
127 | AV_RESAMPLE_DITHER_TRIANGULAR_HP, /**< Triangular Dither with High Pass */ | |
128 | AV_RESAMPLE_DITHER_TRIANGULAR_NS, /**< Triangular Dither with Noise Shaping */ | |
129 | AV_RESAMPLE_DITHER_NB, /**< Number of dither types. Not part of ABI. */ | |
130 | }; | |
131 | ||
132 | /** | |
133 | * Return the LIBAVRESAMPLE_VERSION_INT constant. | |
134 | */ | |
135 | unsigned avresample_version(void); | |
136 | ||
137 | /** | |
138 | * Return the libavresample build-time configuration. | |
139 | * @return configure string | |
140 | */ | |
141 | const char *avresample_configuration(void); | |
142 | ||
143 | /** | |
144 | * Return the libavresample license. | |
145 | */ | |
146 | const char *avresample_license(void); | |
147 | ||
148 | /** | |
149 | * Get the AVClass for AVAudioResampleContext. | |
150 | * | |
151 | * Can be used in combination with AV_OPT_SEARCH_FAKE_OBJ for examining options | |
152 | * without allocating a context. | |
153 | * | |
154 | * @see av_opt_find(). | |
155 | * | |
156 | * @return AVClass for AVAudioResampleContext | |
157 | */ | |
158 | const AVClass *avresample_get_class(void); | |
159 | ||
160 | /** | |
161 | * Allocate AVAudioResampleContext and set options. | |
162 | * | |
163 | * @return allocated audio resample context, or NULL on failure | |
164 | */ | |
165 | AVAudioResampleContext *avresample_alloc_context(void); | |
166 | ||
167 | /** | |
168 | * Initialize AVAudioResampleContext. | |
169 | * @note The context must be configured using the AVOption API. | |
170 | * | |
171 | * @see av_opt_set_int() | |
172 | * @see av_opt_set_dict() | |
173 | * | |
174 | * @param avr audio resample context | |
175 | * @return 0 on success, negative AVERROR code on failure | |
176 | */ | |
177 | int avresample_open(AVAudioResampleContext *avr); | |
178 | ||
179 | /** | |
180 | * Check whether an AVAudioResampleContext is open or closed. | |
181 | * | |
182 | * @param avr AVAudioResampleContext to check | |
183 | * @return 1 if avr is open, 0 if avr is closed. | |
184 | */ | |
185 | int avresample_is_open(AVAudioResampleContext *avr); | |
186 | ||
187 | /** | |
188 | * Close AVAudioResampleContext. | |
189 | * | |
190 | * This closes the context, but it does not change the parameters. The context | |
191 | * can be reopened with avresample_open(). It does, however, clear the output | |
192 | * FIFO and any remaining leftover samples in the resampling delay buffer. If | |
193 | * there was a custom matrix being used, that is also cleared. | |
194 | * | |
195 | * @see avresample_convert() | |
196 | * @see avresample_set_matrix() | |
197 | * | |
198 | * @param avr audio resample context | |
199 | */ | |
200 | void avresample_close(AVAudioResampleContext *avr); | |
201 | ||
202 | /** | |
203 | * Free AVAudioResampleContext and associated AVOption values. | |
204 | * | |
205 | * This also calls avresample_close() before freeing. | |
206 | * | |
207 | * @param avr audio resample context | |
208 | */ | |
209 | void avresample_free(AVAudioResampleContext **avr); | |
210 | ||
211 | /** | |
212 | * Generate a channel mixing matrix. | |
213 | * | |
214 | * This function is the one used internally by libavresample for building the | |
215 | * default mixing matrix. It is made public just as a utility function for | |
216 | * building custom matrices. | |
217 | * | |
218 | * @param in_layout input channel layout | |
219 | * @param out_layout output channel layout | |
220 | * @param center_mix_level mix level for the center channel | |
221 | * @param surround_mix_level mix level for the surround channel(s) | |
222 | * @param lfe_mix_level mix level for the low-frequency effects channel | |
223 | * @param normalize if 1, coefficients will be normalized to prevent | |
224 | * overflow. if 0, coefficients will not be | |
225 | * normalized. | |
226 | * @param[out] matrix mixing coefficients; matrix[i + stride * o] is | |
227 | * the weight of input channel i in output channel o. | |
228 | * @param stride distance between adjacent input channels in the | |
229 | * matrix array | |
230 | * @param matrix_encoding matrixed stereo downmix mode (e.g. dplii) | |
231 | * @return 0 on success, negative AVERROR code on failure | |
232 | */ | |
233 | int avresample_build_matrix(uint64_t in_layout, uint64_t out_layout, | |
234 | double center_mix_level, double surround_mix_level, | |
235 | double lfe_mix_level, int normalize, double *matrix, | |
236 | int stride, enum AVMatrixEncoding matrix_encoding); | |
237 | ||
238 | /** | |
239 | * Get the current channel mixing matrix. | |
240 | * | |
241 | * If no custom matrix has been previously set or the AVAudioResampleContext is | |
242 | * not open, an error is returned. | |
243 | * | |
244 | * @param avr audio resample context | |
245 | * @param matrix mixing coefficients; matrix[i + stride * o] is the weight of | |
246 | * input channel i in output channel o. | |
247 | * @param stride distance between adjacent input channels in the matrix array | |
248 | * @return 0 on success, negative AVERROR code on failure | |
249 | */ | |
250 | int avresample_get_matrix(AVAudioResampleContext *avr, double *matrix, | |
251 | int stride); | |
252 | ||
253 | /** | |
254 | * Set channel mixing matrix. | |
255 | * | |
256 | * Allows for setting a custom mixing matrix, overriding the default matrix | |
257 | * generated internally during avresample_open(). This function can be called | |
258 | * anytime on an allocated context, either before or after calling | |
259 | * avresample_open(), as long as the channel layouts have been set. | |
260 | * avresample_convert() always uses the current matrix. | |
261 | * Calling avresample_close() on the context will clear the current matrix. | |
262 | * | |
263 | * @see avresample_close() | |
264 | * | |
265 | * @param avr audio resample context | |
266 | * @param matrix mixing coefficients; matrix[i + stride * o] is the weight of | |
267 | * input channel i in output channel o. | |
268 | * @param stride distance between adjacent input channels in the matrix array | |
269 | * @return 0 on success, negative AVERROR code on failure | |
270 | */ | |
271 | int avresample_set_matrix(AVAudioResampleContext *avr, const double *matrix, | |
272 | int stride); | |
273 | ||
274 | /** | |
275 | * Set a customized input channel mapping. | |
276 | * | |
277 | * This function can only be called when the allocated context is not open. | |
278 | * Also, the input channel layout must have already been set. | |
279 | * | |
280 | * Calling avresample_close() on the context will clear the channel mapping. | |
281 | * | |
282 | * The map for each input channel specifies the channel index in the source to | |
283 | * use for that particular channel, or -1 to mute the channel. Source channels | |
284 | * can be duplicated by using the same index for multiple input channels. | |
285 | * | |
286 | * Examples: | |
287 | * | |
288 | * Reordering 5.1 AAC order (C,L,R,Ls,Rs,LFE) to FFmpeg order (L,R,C,LFE,Ls,Rs): | |
289 | * { 1, 2, 0, 5, 3, 4 } | |
290 | * | |
291 | * Muting the 3rd channel in 4-channel input: | |
292 | * { 0, 1, -1, 3 } | |
293 | * | |
294 | * Duplicating the left channel of stereo input: | |
295 | * { 0, 0 } | |
296 | * | |
297 | * @param avr audio resample context | |
298 | * @param channel_map customized input channel mapping | |
299 | * @return 0 on success, negative AVERROR code on failure | |
300 | */ | |
301 | int avresample_set_channel_mapping(AVAudioResampleContext *avr, | |
302 | const int *channel_map); | |
303 | ||
304 | /** | |
305 | * Set compensation for resampling. | |
306 | * | |
307 | * This can be called anytime after avresample_open(). If resampling is not | |
308 | * automatically enabled because of a sample rate conversion, the | |
309 | * "force_resampling" option must have been set to 1 when opening the context | |
310 | * in order to use resampling compensation. | |
311 | * | |
312 | * @param avr audio resample context | |
313 | * @param sample_delta compensation delta, in samples | |
314 | * @param compensation_distance compensation distance, in samples | |
315 | * @return 0 on success, negative AVERROR code on failure | |
316 | */ | |
317 | int avresample_set_compensation(AVAudioResampleContext *avr, int sample_delta, | |
318 | int compensation_distance); | |
319 | ||
320 | /** | |
321 | * Provide the upper bound on the number of samples the configured | |
322 | * conversion would output. | |
323 | * | |
324 | * @param avr audio resample context | |
325 | * @param in_nb_samples number of input samples | |
326 | * | |
327 | * @return number of samples or AVERROR(EINVAL) if the value | |
328 | * would exceed INT_MAX | |
329 | */ | |
330 | ||
331 | int avresample_get_out_samples(AVAudioResampleContext *avr, int in_nb_samples); | |
332 | ||
333 | /** | |
334 | * Convert input samples and write them to the output FIFO. | |
335 | * | |
336 | * The upper bound on the number of output samples can be obtained through | |
337 | * avresample_get_out_samples(). | |
338 | * | |
339 | * The output data can be NULL or have fewer allocated samples than required. | |
340 | * In this case, any remaining samples not written to the output will be added | |
341 | * to an internal FIFO buffer, to be returned at the next call to this function | |
342 | * or to avresample_read(). | |
343 | * | |
344 | * If converting sample rate, there may be data remaining in the internal | |
345 | * resampling delay buffer. avresample_get_delay() tells the number of remaining | |
346 | * samples. To get this data as output, call avresample_convert() with NULL | |
347 | * input. | |
348 | * | |
349 | * At the end of the conversion process, there may be data remaining in the | |
350 | * internal FIFO buffer. avresample_available() tells the number of remaining | |
351 | * samples. To get this data as output, either call avresample_convert() with | |
352 | * NULL input or call avresample_read(). | |
353 | * | |
354 | * @see avresample_get_out_samples() | |
355 | * @see avresample_read() | |
356 | * @see avresample_get_delay() | |
357 | * | |
358 | * @param avr audio resample context | |
359 | * @param output output data pointers | |
360 | * @param out_plane_size output plane size, in bytes. | |
361 | * This can be 0 if unknown, but that will lead to | |
362 | * optimized functions not being used directly on the | |
363 | * output, which could slow down some conversions. | |
364 | * @param out_samples maximum number of samples that the output buffer can hold | |
365 | * @param input input data pointers | |
366 | * @param in_plane_size input plane size, in bytes | |
367 | * This can be 0 if unknown, but that will lead to | |
368 | * optimized functions not being used directly on the | |
369 | * input, which could slow down some conversions. | |
370 | * @param in_samples number of input samples to convert | |
371 | * @return number of samples written to the output buffer, | |
372 | * not including converted samples added to the internal | |
373 | * output FIFO | |
374 | */ | |
375 | int avresample_convert(AVAudioResampleContext *avr, uint8_t **output, | |
376 | int out_plane_size, int out_samples, uint8_t **input, | |
377 | int in_plane_size, int in_samples); | |
378 | ||
379 | /** | |
380 | * Return the number of samples currently in the resampling delay buffer. | |
381 | * | |
382 | * When resampling, there may be a delay between the input and output. Any | |
383 | * unconverted samples in each call are stored internally in a delay buffer. | |
384 | * This function allows the user to determine the current number of samples in | |
385 | * the delay buffer, which can be useful for synchronization. | |
386 | * | |
387 | * @see avresample_convert() | |
388 | * | |
389 | * @param avr audio resample context | |
390 | * @return number of samples currently in the resampling delay buffer | |
391 | */ | |
392 | int avresample_get_delay(AVAudioResampleContext *avr); | |
393 | ||
394 | /** | |
395 | * Return the number of available samples in the output FIFO. | |
396 | * | |
397 | * During conversion, if the user does not specify an output buffer or | |
398 | * specifies an output buffer that is smaller than what is needed, remaining | |
399 | * samples that are not written to the output are stored to an internal FIFO | |
400 | * buffer. The samples in the FIFO can be read with avresample_read() or | |
401 | * avresample_convert(). | |
402 | * | |
403 | * @see avresample_read() | |
404 | * @see avresample_convert() | |
405 | * | |
406 | * @param avr audio resample context | |
407 | * @return number of samples available for reading | |
408 | */ | |
409 | int avresample_available(AVAudioResampleContext *avr); | |
410 | ||
411 | /** | |
412 | * Read samples from the output FIFO. | |
413 | * | |
414 | * During conversion, if the user does not specify an output buffer or | |
415 | * specifies an output buffer that is smaller than what is needed, remaining | |
416 | * samples that are not written to the output are stored to an internal FIFO | |
417 | * buffer. This function can be used to read samples from that internal FIFO. | |
418 | * | |
419 | * @see avresample_available() | |
420 | * @see avresample_convert() | |
421 | * | |
422 | * @param avr audio resample context | |
423 | * @param output output data pointers. May be NULL, in which case | |
424 | * nb_samples of data is discarded from output FIFO. | |
425 | * @param nb_samples number of samples to read from the FIFO | |
426 | * @return the number of samples written to output | |
427 | */ | |
428 | int avresample_read(AVAudioResampleContext *avr, uint8_t **output, int nb_samples); | |
429 | ||
430 | /** | |
431 | * Convert the samples in the input AVFrame and write them to the output AVFrame. | |
432 | * | |
433 | * Input and output AVFrames must have channel_layout, sample_rate and format set. | |
434 | * | |
435 | * The upper bound on the number of output samples is obtained through | |
436 | * avresample_get_out_samples(). | |
437 | * | |
438 | * If the output AVFrame does not have the data pointers allocated the nb_samples | |
439 | * field will be set using avresample_get_out_samples() and av_frame_get_buffer() | |
440 | * is called to allocate the frame. | |
441 | * | |
442 | * The output AVFrame can be NULL or have fewer allocated samples than required. | |
443 | * In this case, any remaining samples not written to the output will be added | |
444 | * to an internal FIFO buffer, to be returned at the next call to this function | |
445 | * or to avresample_convert() or to avresample_read(). | |
446 | * | |
447 | * If converting sample rate, there may be data remaining in the internal | |
448 | * resampling delay buffer. avresample_get_delay() tells the number of | |
449 | * remaining samples. To get this data as output, call this function or | |
450 | * avresample_convert() with NULL input. | |
451 | * | |
452 | * At the end of the conversion process, there may be data remaining in the | |
453 | * internal FIFO buffer. avresample_available() tells the number of remaining | |
454 | * samples. To get this data as output, either call this function or | |
455 | * avresample_convert() with NULL input or call avresample_read(). | |
456 | * | |
457 | * If the AVAudioResampleContext configuration does not match the output and | |
458 | * input AVFrame settings the conversion does not take place and depending on | |
459 | * which AVFrame is not matching AVERROR_OUTPUT_CHANGED, AVERROR_INPUT_CHANGED | |
460 | * or AVERROR_OUTPUT_CHANGED|AVERROR_INPUT_CHANGED is returned. | |
461 | * | |
462 | * @see avresample_get_out_samples() | |
463 | * @see avresample_available() | |
464 | * @see avresample_convert() | |
465 | * @see avresample_read() | |
466 | * @see avresample_get_delay() | |
467 | * | |
468 | * @param avr audio resample context | |
469 | * @param output output AVFrame | |
470 | * @param input input AVFrame | |
471 | * @return 0 on success, AVERROR on failure or nonmatching | |
472 | * configuration. | |
473 | */ | |
474 | int avresample_convert_frame(AVAudioResampleContext *avr, | |
475 | AVFrame *output, AVFrame *input); | |
476 | ||
477 | /** | |
478 | * Configure or reconfigure the AVAudioResampleContext using the information | |
479 | * provided by the AVFrames. | |
480 | * | |
481 | * The original resampling context is reset even on failure. | |
482 | * The function calls avresample_close() internally if the context is open. | |
483 | * | |
484 | * @see avresample_open(); | |
485 | * @see avresample_close(); | |
486 | * | |
487 | * @param avr audio resample context | |
488 | * @param output output AVFrame | |
489 | * @param input input AVFrame | |
490 | * @return 0 on success, AVERROR on failure. | |
491 | */ | |
492 | int avresample_config(AVAudioResampleContext *avr, AVFrame *out, AVFrame *in); | |
493 | ||
494 | /** | |
495 | * @} | |
496 | */ | |
497 | ||
498 | #endif /* AVRESAMPLE_AVRESAMPLE_H */ |