lavr: return an error if a avresample_open() is called on an open context
[libav.git] / libavresample / utils.c
1 /*
2 * Copyright (c) 2012 Justin Ruggles <justin.ruggles@gmail.com>
3 *
4 * This file is part of Libav.
5 *
6 * Libav 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 * Libav 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 Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #include "libavutil/common.h"
22 #include "libavutil/dict.h"
23 #include "libavutil/error.h"
24 #include "libavutil/log.h"
25 #include "libavutil/mem.h"
26 #include "libavutil/opt.h"
27
28 #include "avresample.h"
29 #include "internal.h"
30 #include "audio_data.h"
31 #include "audio_convert.h"
32 #include "audio_mix.h"
33 #include "resample.h"
34
35 int avresample_open(AVAudioResampleContext *avr)
36 {
37 int ret;
38
39 if (avresample_is_open(avr)) {
40 av_log(avr, AV_LOG_ERROR, "The resampling context is already open.\n");
41 return AVERROR(EINVAL);
42 }
43
44 /* set channel mixing parameters */
45 avr->in_channels = av_get_channel_layout_nb_channels(avr->in_channel_layout);
46 if (avr->in_channels <= 0 || avr->in_channels > AVRESAMPLE_MAX_CHANNELS) {
47 av_log(avr, AV_LOG_ERROR, "Invalid input channel layout: %"PRIu64"\n",
48 avr->in_channel_layout);
49 return AVERROR(EINVAL);
50 }
51 avr->out_channels = av_get_channel_layout_nb_channels(avr->out_channel_layout);
52 if (avr->out_channels <= 0 || avr->out_channels > AVRESAMPLE_MAX_CHANNELS) {
53 av_log(avr, AV_LOG_ERROR, "Invalid output channel layout: %"PRIu64"\n",
54 avr->out_channel_layout);
55 return AVERROR(EINVAL);
56 }
57 avr->resample_channels = FFMIN(avr->in_channels, avr->out_channels);
58 avr->downmix_needed = avr->in_channels > avr->out_channels;
59 avr->upmix_needed = avr->out_channels > avr->in_channels ||
60 (!avr->downmix_needed && (avr->mix_matrix ||
61 avr->in_channel_layout != avr->out_channel_layout));
62 avr->mixing_needed = avr->downmix_needed || avr->upmix_needed;
63
64 /* set resampling parameters */
65 avr->resample_needed = avr->in_sample_rate != avr->out_sample_rate ||
66 avr->force_resampling;
67
68 /* select internal sample format if not specified by the user */
69 if (avr->internal_sample_fmt == AV_SAMPLE_FMT_NONE &&
70 (avr->mixing_needed || avr->resample_needed)) {
71 enum AVSampleFormat in_fmt = av_get_planar_sample_fmt(avr->in_sample_fmt);
72 enum AVSampleFormat out_fmt = av_get_planar_sample_fmt(avr->out_sample_fmt);
73 int max_bps = FFMAX(av_get_bytes_per_sample(in_fmt),
74 av_get_bytes_per_sample(out_fmt));
75 if (max_bps <= 2) {
76 avr->internal_sample_fmt = AV_SAMPLE_FMT_S16P;
77 } else if (avr->mixing_needed) {
78 avr->internal_sample_fmt = AV_SAMPLE_FMT_FLTP;
79 } else {
80 if (max_bps <= 4) {
81 if (in_fmt == AV_SAMPLE_FMT_S32P ||
82 out_fmt == AV_SAMPLE_FMT_S32P) {
83 if (in_fmt == AV_SAMPLE_FMT_FLTP ||
84 out_fmt == AV_SAMPLE_FMT_FLTP) {
85 /* if one is s32 and the other is flt, use dbl */
86 avr->internal_sample_fmt = AV_SAMPLE_FMT_DBLP;
87 } else {
88 /* if one is s32 and the other is s32, s16, or u8, use s32 */
89 avr->internal_sample_fmt = AV_SAMPLE_FMT_S32P;
90 }
91 } else {
92 /* if one is flt and the other is flt, s16 or u8, use flt */
93 avr->internal_sample_fmt = AV_SAMPLE_FMT_FLTP;
94 }
95 } else {
96 /* if either is dbl, use dbl */
97 avr->internal_sample_fmt = AV_SAMPLE_FMT_DBLP;
98 }
99 }
100 av_log(avr, AV_LOG_DEBUG, "Using %s as internal sample format\n",
101 av_get_sample_fmt_name(avr->internal_sample_fmt));
102 }
103
104 /* treat all mono as planar for easier comparison */
105 if (avr->in_channels == 1)
106 avr->in_sample_fmt = av_get_planar_sample_fmt(avr->in_sample_fmt);
107 if (avr->out_channels == 1)
108 avr->out_sample_fmt = av_get_planar_sample_fmt(avr->out_sample_fmt);
109
110 /* we may need to add an extra conversion in order to remap channels if
111 the output format is not planar */
112 if (avr->use_channel_map && !avr->mixing_needed && !avr->resample_needed &&
113 !av_sample_fmt_is_planar(avr->out_sample_fmt)) {
114 avr->internal_sample_fmt = av_get_planar_sample_fmt(avr->out_sample_fmt);
115 }
116
117 /* set sample format conversion parameters */
118 if (avr->resample_needed || avr->mixing_needed)
119 avr->in_convert_needed = avr->in_sample_fmt != avr->internal_sample_fmt;
120 else
121 avr->in_convert_needed = avr->use_channel_map &&
122 !av_sample_fmt_is_planar(avr->out_sample_fmt);
123
124 if (avr->resample_needed || avr->mixing_needed || avr->in_convert_needed)
125 avr->out_convert_needed = avr->internal_sample_fmt != avr->out_sample_fmt;
126 else
127 avr->out_convert_needed = avr->in_sample_fmt != avr->out_sample_fmt;
128
129 avr->in_copy_needed = !avr->in_convert_needed && (avr->mixing_needed ||
130 (avr->use_channel_map && avr->resample_needed));
131
132 if (avr->use_channel_map) {
133 if (avr->in_copy_needed) {
134 avr->remap_point = REMAP_IN_COPY;
135 av_dlog(avr, "remap channels during in_copy\n");
136 } else if (avr->in_convert_needed) {
137 avr->remap_point = REMAP_IN_CONVERT;
138 av_dlog(avr, "remap channels during in_convert\n");
139 } else if (avr->out_convert_needed) {
140 avr->remap_point = REMAP_OUT_CONVERT;
141 av_dlog(avr, "remap channels during out_convert\n");
142 } else {
143 avr->remap_point = REMAP_OUT_COPY;
144 av_dlog(avr, "remap channels during out_copy\n");
145 }
146
147 #ifdef DEBUG
148 {
149 int ch;
150 av_dlog(avr, "output map: ");
151 if (avr->ch_map_info.do_remap)
152 for (ch = 0; ch < avr->in_channels; ch++)
153 av_dlog(avr, " % 2d", avr->ch_map_info.channel_map[ch]);
154 else
155 av_dlog(avr, "n/a");
156 av_dlog(avr, "\n");
157 av_dlog(avr, "copy map: ");
158 if (avr->ch_map_info.do_copy)
159 for (ch = 0; ch < avr->in_channels; ch++)
160 av_dlog(avr, " % 2d", avr->ch_map_info.channel_copy[ch]);
161 else
162 av_dlog(avr, "n/a");
163 av_dlog(avr, "\n");
164 av_dlog(avr, "zero map: ");
165 if (avr->ch_map_info.do_zero)
166 for (ch = 0; ch < avr->in_channels; ch++)
167 av_dlog(avr, " % 2d", avr->ch_map_info.channel_zero[ch]);
168 else
169 av_dlog(avr, "n/a");
170 av_dlog(avr, "\n");
171 av_dlog(avr, "input map: ");
172 for (ch = 0; ch < avr->in_channels; ch++)
173 av_dlog(avr, " % 2d", avr->ch_map_info.input_map[ch]);
174 av_dlog(avr, "\n");
175 }
176 #endif
177 } else
178 avr->remap_point = REMAP_NONE;
179
180 /* allocate buffers */
181 if (avr->in_copy_needed || avr->in_convert_needed) {
182 avr->in_buffer = ff_audio_data_alloc(FFMAX(avr->in_channels, avr->out_channels),
183 0, avr->internal_sample_fmt,
184 "in_buffer");
185 if (!avr->in_buffer) {
186 ret = AVERROR(EINVAL);
187 goto error;
188 }
189 }
190 if (avr->resample_needed) {
191 avr->resample_out_buffer = ff_audio_data_alloc(avr->out_channels,
192 0, avr->internal_sample_fmt,
193 "resample_out_buffer");
194 if (!avr->resample_out_buffer) {
195 ret = AVERROR(EINVAL);
196 goto error;
197 }
198 }
199 if (avr->out_convert_needed) {
200 avr->out_buffer = ff_audio_data_alloc(avr->out_channels, 0,
201 avr->out_sample_fmt, "out_buffer");
202 if (!avr->out_buffer) {
203 ret = AVERROR(EINVAL);
204 goto error;
205 }
206 }
207 avr->out_fifo = av_audio_fifo_alloc(avr->out_sample_fmt, avr->out_channels,
208 1024);
209 if (!avr->out_fifo) {
210 ret = AVERROR(ENOMEM);
211 goto error;
212 }
213
214 /* setup contexts */
215 if (avr->in_convert_needed) {
216 avr->ac_in = ff_audio_convert_alloc(avr, avr->internal_sample_fmt,
217 avr->in_sample_fmt, avr->in_channels,
218 avr->in_sample_rate,
219 avr->remap_point == REMAP_IN_CONVERT);
220 if (!avr->ac_in) {
221 ret = AVERROR(ENOMEM);
222 goto error;
223 }
224 }
225 if (avr->out_convert_needed) {
226 enum AVSampleFormat src_fmt;
227 if (avr->in_convert_needed)
228 src_fmt = avr->internal_sample_fmt;
229 else
230 src_fmt = avr->in_sample_fmt;
231 avr->ac_out = ff_audio_convert_alloc(avr, avr->out_sample_fmt, src_fmt,
232 avr->out_channels,
233 avr->out_sample_rate,
234 avr->remap_point == REMAP_OUT_CONVERT);
235 if (!avr->ac_out) {
236 ret = AVERROR(ENOMEM);
237 goto error;
238 }
239 }
240 if (avr->resample_needed) {
241 avr->resample = ff_audio_resample_init(avr);
242 if (!avr->resample) {
243 ret = AVERROR(ENOMEM);
244 goto error;
245 }
246 }
247 if (avr->mixing_needed) {
248 avr->am = ff_audio_mix_alloc(avr);
249 if (!avr->am) {
250 ret = AVERROR(ENOMEM);
251 goto error;
252 }
253 }
254
255 return 0;
256
257 error:
258 avresample_close(avr);
259 return ret;
260 }
261
262 int avresample_is_open(AVAudioResampleContext *avr)
263 {
264 return !!avr->out_fifo;
265 }
266
267 void avresample_close(AVAudioResampleContext *avr)
268 {
269 ff_audio_data_free(&avr->in_buffer);
270 ff_audio_data_free(&avr->resample_out_buffer);
271 ff_audio_data_free(&avr->out_buffer);
272 av_audio_fifo_free(avr->out_fifo);
273 avr->out_fifo = NULL;
274 ff_audio_convert_free(&avr->ac_in);
275 ff_audio_convert_free(&avr->ac_out);
276 ff_audio_resample_free(&avr->resample);
277 ff_audio_mix_free(&avr->am);
278 av_freep(&avr->mix_matrix);
279
280 avr->use_channel_map = 0;
281 }
282
283 void avresample_free(AVAudioResampleContext **avr)
284 {
285 if (!*avr)
286 return;
287 avresample_close(*avr);
288 av_opt_free(*avr);
289 av_freep(avr);
290 }
291
292 static int handle_buffered_output(AVAudioResampleContext *avr,
293 AudioData *output, AudioData *converted)
294 {
295 int ret;
296
297 if (!output || av_audio_fifo_size(avr->out_fifo) > 0 ||
298 (converted && output->allocated_samples < converted->nb_samples)) {
299 if (converted) {
300 /* if there are any samples in the output FIFO or if the
301 user-supplied output buffer is not large enough for all samples,
302 we add to the output FIFO */
303 av_dlog(avr, "[FIFO] add %s to out_fifo\n", converted->name);
304 ret = ff_audio_data_add_to_fifo(avr->out_fifo, converted, 0,
305 converted->nb_samples);
306 if (ret < 0)
307 return ret;
308 }
309
310 /* if the user specified an output buffer, read samples from the output
311 FIFO to the user output */
312 if (output && output->allocated_samples > 0) {
313 av_dlog(avr, "[FIFO] read from out_fifo to output\n");
314 av_dlog(avr, "[end conversion]\n");
315 return ff_audio_data_read_from_fifo(avr->out_fifo, output,
316 output->allocated_samples);
317 }
318 } else if (converted) {
319 /* copy directly to output if it is large enough or there is not any
320 data in the output FIFO */
321 av_dlog(avr, "[copy] %s to output\n", converted->name);
322 output->nb_samples = 0;
323 ret = ff_audio_data_copy(output, converted,
324 avr->remap_point == REMAP_OUT_COPY ?
325 &avr->ch_map_info : NULL);
326 if (ret < 0)
327 return ret;
328 av_dlog(avr, "[end conversion]\n");
329 return output->nb_samples;
330 }
331 av_dlog(avr, "[end conversion]\n");
332 return 0;
333 }
334
335 int attribute_align_arg avresample_convert(AVAudioResampleContext *avr,
336 uint8_t **output, int out_plane_size,
337 int out_samples, uint8_t **input,
338 int in_plane_size, int in_samples)
339 {
340 AudioData input_buffer;
341 AudioData output_buffer;
342 AudioData *current_buffer;
343 int ret, direct_output;
344
345 /* reset internal buffers */
346 if (avr->in_buffer) {
347 avr->in_buffer->nb_samples = 0;
348 ff_audio_data_set_channels(avr->in_buffer,
349 avr->in_buffer->allocated_channels);
350 }
351 if (avr->resample_out_buffer) {
352 avr->resample_out_buffer->nb_samples = 0;
353 ff_audio_data_set_channels(avr->resample_out_buffer,
354 avr->resample_out_buffer->allocated_channels);
355 }
356 if (avr->out_buffer) {
357 avr->out_buffer->nb_samples = 0;
358 ff_audio_data_set_channels(avr->out_buffer,
359 avr->out_buffer->allocated_channels);
360 }
361
362 av_dlog(avr, "[start conversion]\n");
363
364 /* initialize output_buffer with output data */
365 direct_output = output && av_audio_fifo_size(avr->out_fifo) == 0;
366 if (output) {
367 ret = ff_audio_data_init(&output_buffer, output, out_plane_size,
368 avr->out_channels, out_samples,
369 avr->out_sample_fmt, 0, "output");
370 if (ret < 0)
371 return ret;
372 output_buffer.nb_samples = 0;
373 }
374
375 if (input) {
376 /* initialize input_buffer with input data */
377 ret = ff_audio_data_init(&input_buffer, input, in_plane_size,
378 avr->in_channels, in_samples,
379 avr->in_sample_fmt, 1, "input");
380 if (ret < 0)
381 return ret;
382 current_buffer = &input_buffer;
383
384 if (avr->upmix_needed && !avr->in_convert_needed && !avr->resample_needed &&
385 !avr->out_convert_needed && direct_output && out_samples >= in_samples) {
386 /* in some rare cases we can copy input to output and upmix
387 directly in the output buffer */
388 av_dlog(avr, "[copy] %s to output\n", current_buffer->name);
389 ret = ff_audio_data_copy(&output_buffer, current_buffer,
390 avr->remap_point == REMAP_OUT_COPY ?
391 &avr->ch_map_info : NULL);
392 if (ret < 0)
393 return ret;
394 current_buffer = &output_buffer;
395 } else if (avr->remap_point == REMAP_OUT_COPY &&
396 (!direct_output || out_samples < in_samples)) {
397 /* if remapping channels during output copy, we may need to
398 * use an intermediate buffer in order to remap before adding
399 * samples to the output fifo */
400 av_dlog(avr, "[copy] %s to out_buffer\n", current_buffer->name);
401 ret = ff_audio_data_copy(avr->out_buffer, current_buffer,
402 &avr->ch_map_info);
403 if (ret < 0)
404 return ret;
405 current_buffer = avr->out_buffer;
406 } else if (avr->in_copy_needed || avr->in_convert_needed) {
407 /* if needed, copy or convert input to in_buffer, and downmix if
408 applicable */
409 if (avr->in_convert_needed) {
410 ret = ff_audio_data_realloc(avr->in_buffer,
411 current_buffer->nb_samples);
412 if (ret < 0)
413 return ret;
414 av_dlog(avr, "[convert] %s to in_buffer\n", current_buffer->name);
415 ret = ff_audio_convert(avr->ac_in, avr->in_buffer,
416 current_buffer);
417 if (ret < 0)
418 return ret;
419 } else {
420 av_dlog(avr, "[copy] %s to in_buffer\n", current_buffer->name);
421 ret = ff_audio_data_copy(avr->in_buffer, current_buffer,
422 avr->remap_point == REMAP_IN_COPY ?
423 &avr->ch_map_info : NULL);
424 if (ret < 0)
425 return ret;
426 }
427 ff_audio_data_set_channels(avr->in_buffer, avr->in_channels);
428 if (avr->downmix_needed) {
429 av_dlog(avr, "[downmix] in_buffer\n");
430 ret = ff_audio_mix(avr->am, avr->in_buffer);
431 if (ret < 0)
432 return ret;
433 }
434 current_buffer = avr->in_buffer;
435 }
436 } else {
437 /* flush resampling buffer and/or output FIFO if input is NULL */
438 if (!avr->resample_needed)
439 return handle_buffered_output(avr, output ? &output_buffer : NULL,
440 NULL);
441 current_buffer = NULL;
442 }
443
444 if (avr->resample_needed) {
445 AudioData *resample_out;
446
447 if (!avr->out_convert_needed && direct_output && out_samples > 0)
448 resample_out = &output_buffer;
449 else
450 resample_out = avr->resample_out_buffer;
451 av_dlog(avr, "[resample] %s to %s\n",
452 current_buffer ? current_buffer->name : "null",
453 resample_out->name);
454 ret = ff_audio_resample(avr->resample, resample_out,
455 current_buffer);
456 if (ret < 0)
457 return ret;
458
459 /* if resampling did not produce any samples, just return 0 */
460 if (resample_out->nb_samples == 0) {
461 av_dlog(avr, "[end conversion]\n");
462 return 0;
463 }
464
465 current_buffer = resample_out;
466 }
467
468 if (avr->upmix_needed) {
469 av_dlog(avr, "[upmix] %s\n", current_buffer->name);
470 ret = ff_audio_mix(avr->am, current_buffer);
471 if (ret < 0)
472 return ret;
473 }
474
475 /* if we resampled or upmixed directly to output, return here */
476 if (current_buffer == &output_buffer) {
477 av_dlog(avr, "[end conversion]\n");
478 return current_buffer->nb_samples;
479 }
480
481 if (avr->out_convert_needed) {
482 if (direct_output && out_samples >= current_buffer->nb_samples) {
483 /* convert directly to output */
484 av_dlog(avr, "[convert] %s to output\n", current_buffer->name);
485 ret = ff_audio_convert(avr->ac_out, &output_buffer, current_buffer);
486 if (ret < 0)
487 return ret;
488
489 av_dlog(avr, "[end conversion]\n");
490 return output_buffer.nb_samples;
491 } else {
492 ret = ff_audio_data_realloc(avr->out_buffer,
493 current_buffer->nb_samples);
494 if (ret < 0)
495 return ret;
496 av_dlog(avr, "[convert] %s to out_buffer\n", current_buffer->name);
497 ret = ff_audio_convert(avr->ac_out, avr->out_buffer,
498 current_buffer);
499 if (ret < 0)
500 return ret;
501 current_buffer = avr->out_buffer;
502 }
503 }
504
505 return handle_buffered_output(avr, output ? &output_buffer : NULL,
506 current_buffer);
507 }
508
509 int avresample_get_matrix(AVAudioResampleContext *avr, double *matrix,
510 int stride)
511 {
512 int in_channels, out_channels, i, o;
513
514 if (avr->am)
515 return ff_audio_mix_get_matrix(avr->am, matrix, stride);
516
517 in_channels = av_get_channel_layout_nb_channels(avr->in_channel_layout);
518 out_channels = av_get_channel_layout_nb_channels(avr->out_channel_layout);
519
520 if ( in_channels <= 0 || in_channels > AVRESAMPLE_MAX_CHANNELS ||
521 out_channels <= 0 || out_channels > AVRESAMPLE_MAX_CHANNELS) {
522 av_log(avr, AV_LOG_ERROR, "Invalid channel layouts\n");
523 return AVERROR(EINVAL);
524 }
525
526 if (!avr->mix_matrix) {
527 av_log(avr, AV_LOG_ERROR, "matrix is not set\n");
528 return AVERROR(EINVAL);
529 }
530
531 for (o = 0; o < out_channels; o++)
532 for (i = 0; i < in_channels; i++)
533 matrix[o * stride + i] = avr->mix_matrix[o * in_channels + i];
534
535 return 0;
536 }
537
538 int avresample_set_matrix(AVAudioResampleContext *avr, const double *matrix,
539 int stride)
540 {
541 int in_channels, out_channels, i, o;
542
543 if (avr->am)
544 return ff_audio_mix_set_matrix(avr->am, matrix, stride);
545
546 in_channels = av_get_channel_layout_nb_channels(avr->in_channel_layout);
547 out_channels = av_get_channel_layout_nb_channels(avr->out_channel_layout);
548
549 if ( in_channels <= 0 || in_channels > AVRESAMPLE_MAX_CHANNELS ||
550 out_channels <= 0 || out_channels > AVRESAMPLE_MAX_CHANNELS) {
551 av_log(avr, AV_LOG_ERROR, "Invalid channel layouts\n");
552 return AVERROR(EINVAL);
553 }
554
555 if (avr->mix_matrix)
556 av_freep(&avr->mix_matrix);
557 avr->mix_matrix = av_malloc(in_channels * out_channels *
558 sizeof(*avr->mix_matrix));
559 if (!avr->mix_matrix)
560 return AVERROR(ENOMEM);
561
562 for (o = 0; o < out_channels; o++)
563 for (i = 0; i < in_channels; i++)
564 avr->mix_matrix[o * in_channels + i] = matrix[o * stride + i];
565
566 return 0;
567 }
568
569 int avresample_set_channel_mapping(AVAudioResampleContext *avr,
570 const int *channel_map)
571 {
572 ChannelMapInfo *info = &avr->ch_map_info;
573 int in_channels, ch, i;
574
575 in_channels = av_get_channel_layout_nb_channels(avr->in_channel_layout);
576 if (in_channels <= 0 || in_channels > AVRESAMPLE_MAX_CHANNELS) {
577 av_log(avr, AV_LOG_ERROR, "Invalid input channel layout\n");
578 return AVERROR(EINVAL);
579 }
580
581 memset(info, 0, sizeof(*info));
582 memset(info->input_map, -1, sizeof(info->input_map));
583
584 for (ch = 0; ch < in_channels; ch++) {
585 if (channel_map[ch] >= in_channels) {
586 av_log(avr, AV_LOG_ERROR, "Invalid channel map\n");
587 return AVERROR(EINVAL);
588 }
589 if (channel_map[ch] < 0) {
590 info->channel_zero[ch] = 1;
591 info->channel_map[ch] = -1;
592 info->do_zero = 1;
593 } else if (info->input_map[channel_map[ch]] >= 0) {
594 info->channel_copy[ch] = info->input_map[channel_map[ch]];
595 info->channel_map[ch] = -1;
596 info->do_copy = 1;
597 } else {
598 info->channel_map[ch] = channel_map[ch];
599 info->input_map[channel_map[ch]] = ch;
600 info->do_remap = 1;
601 }
602 }
603 /* Fill-in unmapped input channels with unmapped output channels.
604 This is used when remapping during conversion from interleaved to
605 planar format. */
606 for (ch = 0, i = 0; ch < in_channels && i < in_channels; ch++, i++) {
607 while (ch < in_channels && info->input_map[ch] >= 0)
608 ch++;
609 while (i < in_channels && info->channel_map[i] >= 0)
610 i++;
611 if (ch >= in_channels || i >= in_channels)
612 break;
613 info->input_map[ch] = i;
614 }
615
616 avr->use_channel_map = 1;
617 return 0;
618 }
619
620 int avresample_available(AVAudioResampleContext *avr)
621 {
622 return av_audio_fifo_size(avr->out_fifo);
623 }
624
625 int avresample_read(AVAudioResampleContext *avr, uint8_t **output, int nb_samples)
626 {
627 if (!output)
628 return av_audio_fifo_drain(avr->out_fifo, nb_samples);
629 return av_audio_fifo_read(avr->out_fifo, (void**)output, nb_samples);
630 }
631
632 unsigned avresample_version(void)
633 {
634 return LIBAVRESAMPLE_VERSION_INT;
635 }
636
637 const char *avresample_license(void)
638 {
639 #define LICENSE_PREFIX "libavresample license: "
640 return LICENSE_PREFIX LIBAV_LICENSE + sizeof(LICENSE_PREFIX) - 1;
641 }
642
643 const char *avresample_configuration(void)
644 {
645 return LIBAV_CONFIGURATION;
646 }