2 * Copyright (c) 2012 Justin Ruggles <justin.ruggles@gmail.com>
4 * This file is part of FFmpeg.
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.
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.
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
21 #include "libavutil/common.h"
22 #include "libavutil/dict.h"
23 // #include "libavutil/error.h"
24 #include "libavutil/frame.h"
25 #include "libavutil/log.h"
26 #include "libavutil/mem.h"
27 #include "libavutil/opt.h"
29 #include "avresample.h"
31 #include "audio_data.h"
32 #include "audio_convert.h"
33 #include "audio_mix.h"
36 int avresample_open(AVAudioResampleContext *avr)
40 if (avresample_is_open(avr)) {
41 av_log(avr, AV_LOG_ERROR, "The resampling context is already open.\n");
42 return AVERROR(EINVAL);
45 /* set channel mixing parameters */
46 avr->in_channels = av_get_channel_layout_nb_channels(avr->in_channel_layout);
47 if (avr->in_channels <= 0 || avr->in_channels > AVRESAMPLE_MAX_CHANNELS) {
48 av_log(avr, AV_LOG_ERROR, "Invalid input channel layout: %"PRIu64"\n",
49 avr->in_channel_layout);
50 return AVERROR(EINVAL);
52 avr->out_channels = av_get_channel_layout_nb_channels(avr->out_channel_layout);
53 if (avr->out_channels <= 0 || avr->out_channels > AVRESAMPLE_MAX_CHANNELS) {
54 av_log(avr, AV_LOG_ERROR, "Invalid output channel layout: %"PRIu64"\n",
55 avr->out_channel_layout);
56 return AVERROR(EINVAL);
58 avr->resample_channels = FFMIN(avr->in_channels, avr->out_channels);
59 avr->downmix_needed = avr->in_channels > avr->out_channels;
60 avr->upmix_needed = avr->out_channels > avr->in_channels ||
61 (!avr->downmix_needed && (avr->mix_matrix ||
62 avr->in_channel_layout != avr->out_channel_layout));
63 avr->mixing_needed = avr->downmix_needed || avr->upmix_needed;
65 /* set resampling parameters */
66 avr->resample_needed = avr->in_sample_rate != avr->out_sample_rate ||
67 avr->force_resampling;
69 /* select internal sample format if not specified by the user */
70 if (avr->internal_sample_fmt == AV_SAMPLE_FMT_NONE &&
71 (avr->mixing_needed || avr->resample_needed)) {
72 enum AVSampleFormat in_fmt = av_get_planar_sample_fmt(avr->in_sample_fmt);
73 enum AVSampleFormat out_fmt = av_get_planar_sample_fmt(avr->out_sample_fmt);
74 int max_bps = FFMAX(av_get_bytes_per_sample(in_fmt),
75 av_get_bytes_per_sample(out_fmt));
77 avr->internal_sample_fmt = AV_SAMPLE_FMT_S16P;
78 } else if (avr->mixing_needed) {
79 avr->internal_sample_fmt = AV_SAMPLE_FMT_FLTP;
82 if (in_fmt == AV_SAMPLE_FMT_S32P ||
83 out_fmt == AV_SAMPLE_FMT_S32P) {
84 if (in_fmt == AV_SAMPLE_FMT_FLTP ||
85 out_fmt == AV_SAMPLE_FMT_FLTP) {
86 /* if one is s32 and the other is flt, use dbl */
87 avr->internal_sample_fmt = AV_SAMPLE_FMT_DBLP;
89 /* if one is s32 and the other is s32, s16, or u8, use s32 */
90 avr->internal_sample_fmt = AV_SAMPLE_FMT_S32P;
93 /* if one is flt and the other is flt, s16 or u8, use flt */
94 avr->internal_sample_fmt = AV_SAMPLE_FMT_FLTP;
97 /* if either is dbl, use dbl */
98 avr->internal_sample_fmt = AV_SAMPLE_FMT_DBLP;
101 av_log(avr, AV_LOG_DEBUG, "Using %s as internal sample format\n",
102 av_get_sample_fmt_name(avr->internal_sample_fmt));
105 /* we may need to add an extra conversion in order to remap channels if
106 the output format is not planar */
107 if (avr->use_channel_map && !avr->mixing_needed && !avr->resample_needed &&
108 !ff_sample_fmt_is_planar(avr->out_sample_fmt, avr->out_channels)) {
109 avr->internal_sample_fmt = av_get_planar_sample_fmt(avr->out_sample_fmt);
112 /* set sample format conversion parameters */
113 if (avr->resample_needed || avr->mixing_needed)
114 avr->in_convert_needed = avr->in_sample_fmt != avr->internal_sample_fmt;
116 avr->in_convert_needed = avr->use_channel_map &&
117 !ff_sample_fmt_is_planar(avr->out_sample_fmt, avr->out_channels);
119 if (avr->resample_needed || avr->mixing_needed || avr->in_convert_needed)
120 avr->out_convert_needed = avr->internal_sample_fmt != avr->out_sample_fmt;
122 avr->out_convert_needed = avr->in_sample_fmt != avr->out_sample_fmt;
124 avr->in_copy_needed = !avr->in_convert_needed && (avr->mixing_needed ||
125 (avr->use_channel_map && avr->resample_needed));
127 if (avr->use_channel_map) {
128 if (avr->in_copy_needed) {
129 avr->remap_point = REMAP_IN_COPY;
130 av_dlog(avr, "remap channels during in_copy\n");
131 } else if (avr->in_convert_needed) {
132 avr->remap_point = REMAP_IN_CONVERT;
133 av_dlog(avr, "remap channels during in_convert\n");
134 } else if (avr->out_convert_needed) {
135 avr->remap_point = REMAP_OUT_CONVERT;
136 av_dlog(avr, "remap channels during out_convert\n");
138 avr->remap_point = REMAP_OUT_COPY;
139 av_dlog(avr, "remap channels during out_copy\n");
145 av_dlog(avr, "output map: ");
146 if (avr->ch_map_info.do_remap)
147 for (ch = 0; ch < avr->in_channels; ch++)
148 av_dlog(avr, " % 2d", avr->ch_map_info.channel_map[ch]);
152 av_dlog(avr, "copy map: ");
153 if (avr->ch_map_info.do_copy)
154 for (ch = 0; ch < avr->in_channels; ch++)
155 av_dlog(avr, " % 2d", avr->ch_map_info.channel_copy[ch]);
159 av_dlog(avr, "zero map: ");
160 if (avr->ch_map_info.do_zero)
161 for (ch = 0; ch < avr->in_channels; ch++)
162 av_dlog(avr, " % 2d", avr->ch_map_info.channel_zero[ch]);
166 av_dlog(avr, "input map: ");
167 for (ch = 0; ch < avr->in_channels; ch++)
168 av_dlog(avr, " % 2d", avr->ch_map_info.input_map[ch]);
173 avr->remap_point = REMAP_NONE;
175 /* allocate buffers */
176 if (avr->in_copy_needed || avr->in_convert_needed) {
177 avr->in_buffer = ff_audio_data_alloc(FFMAX(avr->in_channels, avr->out_channels),
178 0, avr->internal_sample_fmt,
180 if (!avr->in_buffer) {
181 ret = AVERROR(EINVAL);
185 if (avr->resample_needed) {
186 avr->resample_out_buffer = ff_audio_data_alloc(avr->out_channels,
187 1024, avr->internal_sample_fmt,
188 "resample_out_buffer");
189 if (!avr->resample_out_buffer) {
190 ret = AVERROR(EINVAL);
194 if (avr->out_convert_needed) {
195 avr->out_buffer = ff_audio_data_alloc(avr->out_channels, 0,
196 avr->out_sample_fmt, "out_buffer");
197 if (!avr->out_buffer) {
198 ret = AVERROR(EINVAL);
202 avr->out_fifo = av_audio_fifo_alloc(avr->out_sample_fmt, avr->out_channels,
204 if (!avr->out_fifo) {
205 ret = AVERROR(ENOMEM);
210 if (avr->in_convert_needed) {
211 avr->ac_in = ff_audio_convert_alloc(avr, avr->internal_sample_fmt,
212 avr->in_sample_fmt, avr->in_channels,
214 avr->remap_point == REMAP_IN_CONVERT);
216 ret = AVERROR(ENOMEM);
220 if (avr->out_convert_needed) {
221 enum AVSampleFormat src_fmt;
222 if (avr->in_convert_needed)
223 src_fmt = avr->internal_sample_fmt;
225 src_fmt = avr->in_sample_fmt;
226 avr->ac_out = ff_audio_convert_alloc(avr, avr->out_sample_fmt, src_fmt,
228 avr->out_sample_rate,
229 avr->remap_point == REMAP_OUT_CONVERT);
231 ret = AVERROR(ENOMEM);
235 if (avr->resample_needed) {
236 avr->resample = ff_audio_resample_init(avr);
237 if (!avr->resample) {
238 ret = AVERROR(ENOMEM);
242 if (avr->mixing_needed) {
243 avr->am = ff_audio_mix_alloc(avr);
245 ret = AVERROR(ENOMEM);
253 avresample_close(avr);
257 int avresample_is_open(AVAudioResampleContext *avr)
259 return !!avr->out_fifo;
262 void avresample_close(AVAudioResampleContext *avr)
264 ff_audio_data_free(&avr->in_buffer);
265 ff_audio_data_free(&avr->resample_out_buffer);
266 ff_audio_data_free(&avr->out_buffer);
267 av_audio_fifo_free(avr->out_fifo);
268 avr->out_fifo = NULL;
269 ff_audio_convert_free(&avr->ac_in);
270 ff_audio_convert_free(&avr->ac_out);
271 ff_audio_resample_free(&avr->resample);
272 ff_audio_mix_free(&avr->am);
273 av_freep(&avr->mix_matrix);
275 avr->use_channel_map = 0;
278 void avresample_free(AVAudioResampleContext **avr)
282 avresample_close(*avr);
287 static int handle_buffered_output(AVAudioResampleContext *avr,
288 AudioData *output, AudioData *converted)
292 if (!output || av_audio_fifo_size(avr->out_fifo) > 0 ||
293 (converted && output->allocated_samples < converted->nb_samples)) {
295 /* if there are any samples in the output FIFO or if the
296 user-supplied output buffer is not large enough for all samples,
297 we add to the output FIFO */
298 av_dlog(avr, "[FIFO] add %s to out_fifo\n", converted->name);
299 ret = ff_audio_data_add_to_fifo(avr->out_fifo, converted, 0,
300 converted->nb_samples);
305 /* if the user specified an output buffer, read samples from the output
306 FIFO to the user output */
307 if (output && output->allocated_samples > 0) {
308 av_dlog(avr, "[FIFO] read from out_fifo to output\n");
309 av_dlog(avr, "[end conversion]\n");
310 return ff_audio_data_read_from_fifo(avr->out_fifo, output,
311 output->allocated_samples);
313 } else if (converted) {
314 /* copy directly to output if it is large enough or there is not any
315 data in the output FIFO */
316 av_dlog(avr, "[copy] %s to output\n", converted->name);
317 output->nb_samples = 0;
318 ret = ff_audio_data_copy(output, converted,
319 avr->remap_point == REMAP_OUT_COPY ?
320 &avr->ch_map_info : NULL);
323 av_dlog(avr, "[end conversion]\n");
324 return output->nb_samples;
326 av_dlog(avr, "[end conversion]\n");
330 int attribute_align_arg avresample_convert(AVAudioResampleContext *avr,
331 uint8_t **output, int out_plane_size,
332 int out_samples, uint8_t **input,
333 int in_plane_size, int in_samples)
335 AudioData input_buffer;
336 AudioData output_buffer;
337 AudioData *current_buffer;
338 int ret, direct_output;
340 /* reset internal buffers */
341 if (avr->in_buffer) {
342 avr->in_buffer->nb_samples = 0;
343 ff_audio_data_set_channels(avr->in_buffer,
344 avr->in_buffer->allocated_channels);
346 if (avr->resample_out_buffer) {
347 avr->resample_out_buffer->nb_samples = 0;
348 ff_audio_data_set_channels(avr->resample_out_buffer,
349 avr->resample_out_buffer->allocated_channels);
351 if (avr->out_buffer) {
352 avr->out_buffer->nb_samples = 0;
353 ff_audio_data_set_channels(avr->out_buffer,
354 avr->out_buffer->allocated_channels);
357 av_dlog(avr, "[start conversion]\n");
359 /* initialize output_buffer with output data */
360 direct_output = output && av_audio_fifo_size(avr->out_fifo) == 0;
362 ret = ff_audio_data_init(&output_buffer, output, out_plane_size,
363 avr->out_channels, out_samples,
364 avr->out_sample_fmt, 0, "output");
367 output_buffer.nb_samples = 0;
371 /* initialize input_buffer with input data */
372 ret = ff_audio_data_init(&input_buffer, input, in_plane_size,
373 avr->in_channels, in_samples,
374 avr->in_sample_fmt, 1, "input");
377 current_buffer = &input_buffer;
379 if (avr->upmix_needed && !avr->in_convert_needed && !avr->resample_needed &&
380 !avr->out_convert_needed && direct_output && out_samples >= in_samples) {
381 /* in some rare cases we can copy input to output and upmix
382 directly in the output buffer */
383 av_dlog(avr, "[copy] %s to output\n", current_buffer->name);
384 ret = ff_audio_data_copy(&output_buffer, current_buffer,
385 avr->remap_point == REMAP_OUT_COPY ?
386 &avr->ch_map_info : NULL);
389 current_buffer = &output_buffer;
390 } else if (avr->remap_point == REMAP_OUT_COPY &&
391 (!direct_output || out_samples < in_samples)) {
392 /* if remapping channels during output copy, we may need to
393 * use an intermediate buffer in order to remap before adding
394 * samples to the output fifo */
395 av_dlog(avr, "[copy] %s to out_buffer\n", current_buffer->name);
396 ret = ff_audio_data_copy(avr->out_buffer, current_buffer,
400 current_buffer = avr->out_buffer;
401 } else if (avr->in_copy_needed || avr->in_convert_needed) {
402 /* if needed, copy or convert input to in_buffer, and downmix if
404 if (avr->in_convert_needed) {
405 ret = ff_audio_data_realloc(avr->in_buffer,
406 current_buffer->nb_samples);
409 av_dlog(avr, "[convert] %s to in_buffer\n", current_buffer->name);
410 ret = ff_audio_convert(avr->ac_in, avr->in_buffer,
415 av_dlog(avr, "[copy] %s to in_buffer\n", current_buffer->name);
416 ret = ff_audio_data_copy(avr->in_buffer, current_buffer,
417 avr->remap_point == REMAP_IN_COPY ?
418 &avr->ch_map_info : NULL);
422 ff_audio_data_set_channels(avr->in_buffer, avr->in_channels);
423 if (avr->downmix_needed) {
424 av_dlog(avr, "[downmix] in_buffer\n");
425 ret = ff_audio_mix(avr->am, avr->in_buffer);
429 current_buffer = avr->in_buffer;
432 /* flush resampling buffer and/or output FIFO if input is NULL */
433 if (!avr->resample_needed)
434 return handle_buffered_output(avr, output ? &output_buffer : NULL,
436 current_buffer = NULL;
439 if (avr->resample_needed) {
440 AudioData *resample_out;
442 if (!avr->out_convert_needed && direct_output && out_samples > 0)
443 resample_out = &output_buffer;
445 resample_out = avr->resample_out_buffer;
446 av_dlog(avr, "[resample] %s to %s\n",
447 current_buffer ? current_buffer->name : "null",
449 ret = ff_audio_resample(avr->resample, resample_out,
454 /* if resampling did not produce any samples, just return 0 */
455 if (resample_out->nb_samples == 0) {
456 av_dlog(avr, "[end conversion]\n");
460 current_buffer = resample_out;
463 if (avr->upmix_needed) {
464 av_dlog(avr, "[upmix] %s\n", current_buffer->name);
465 ret = ff_audio_mix(avr->am, current_buffer);
470 /* if we resampled or upmixed directly to output, return here */
471 if (current_buffer == &output_buffer) {
472 av_dlog(avr, "[end conversion]\n");
473 return current_buffer->nb_samples;
476 if (avr->out_convert_needed) {
477 if (direct_output && out_samples >= current_buffer->nb_samples) {
478 /* convert directly to output */
479 av_dlog(avr, "[convert] %s to output\n", current_buffer->name);
480 ret = ff_audio_convert(avr->ac_out, &output_buffer, current_buffer);
484 av_dlog(avr, "[end conversion]\n");
485 return output_buffer.nb_samples;
487 ret = ff_audio_data_realloc(avr->out_buffer,
488 current_buffer->nb_samples);
491 av_dlog(avr, "[convert] %s to out_buffer\n", current_buffer->name);
492 ret = ff_audio_convert(avr->ac_out, avr->out_buffer,
496 current_buffer = avr->out_buffer;
500 return handle_buffered_output(avr, output ? &output_buffer : NULL,
504 int avresample_config(AVAudioResampleContext *avr, AVFrame *out, AVFrame *in)
506 if (avresample_is_open(avr)) {
507 avresample_close(avr);
511 avr->in_channel_layout = in->channel_layout;
512 avr->in_sample_rate = in->sample_rate;
513 avr->in_sample_fmt = in->format;
517 avr->out_channel_layout = out->channel_layout;
518 avr->out_sample_rate = out->sample_rate;
519 avr->out_sample_fmt = out->format;
525 static int config_changed(AVAudioResampleContext *avr,
526 AVFrame *out, AVFrame *in)
531 if (avr->in_channel_layout != in->channel_layout ||
532 avr->in_sample_rate != in->sample_rate ||
533 avr->in_sample_fmt != in->format) {
534 ret |= AVERROR_INPUT_CHANGED;
539 if (avr->out_channel_layout != out->channel_layout ||
540 avr->out_sample_rate != out->sample_rate ||
541 avr->out_sample_fmt != out->format) {
542 ret |= AVERROR_OUTPUT_CHANGED;
549 static inline int convert_frame(AVAudioResampleContext *avr,
550 AVFrame *out, AVFrame *in)
553 uint8_t **out_data = NULL, **in_data = NULL;
554 int out_linesize = 0, in_linesize = 0;
555 int out_nb_samples = 0, in_nb_samples = 0;
558 out_data = out->extended_data;
559 out_linesize = out->linesize[0];
560 out_nb_samples = out->nb_samples;
564 in_data = in->extended_data;
565 in_linesize = in->linesize[0];
566 in_nb_samples = in->nb_samples;
569 ret = avresample_convert(avr, out_data, out_linesize,
571 in_data, in_linesize,
581 out->nb_samples = ret;
586 static inline int available_samples(AVFrame *out)
589 int bytes_per_sample = av_get_bytes_per_sample(out->format);
590 if (!bytes_per_sample)
591 return AVERROR(EINVAL);
593 samples = out->linesize[0] / bytes_per_sample;
594 if (av_sample_fmt_is_planar(out->format)) {
597 int channels = av_get_channel_layout_nb_channels(out->channel_layout);
598 return samples / channels;
602 int avresample_convert_frame(AVAudioResampleContext *avr,
603 AVFrame *out, AVFrame *in)
607 if (!avresample_is_open(avr)) {
608 if ((ret = avresample_config(avr, out, in)) < 0)
610 if ((ret = avresample_open(avr)) < 0)
614 // return as is or reconfigure for input changes?
615 if ((ret = config_changed(avr, out, in)))
620 if (!out->linesize[0]) {
621 out->nb_samples = avresample_get_out_samples(avr, in->nb_samples);
622 if ((ret = av_frame_get_buffer(out, 0)) < 0) {
624 avresample_close(avr);
628 if (!out->nb_samples)
629 out->nb_samples = available_samples(out);
633 return convert_frame(avr, out, in);
636 int avresample_get_matrix(AVAudioResampleContext *avr, double *matrix,
639 int in_channels, out_channels, i, o;
642 return ff_audio_mix_get_matrix(avr->am, matrix, stride);
644 in_channels = av_get_channel_layout_nb_channels(avr->in_channel_layout);
645 out_channels = av_get_channel_layout_nb_channels(avr->out_channel_layout);
647 if ( in_channels <= 0 || in_channels > AVRESAMPLE_MAX_CHANNELS ||
648 out_channels <= 0 || out_channels > AVRESAMPLE_MAX_CHANNELS) {
649 av_log(avr, AV_LOG_ERROR, "Invalid channel layouts\n");
650 return AVERROR(EINVAL);
653 if (!avr->mix_matrix) {
654 av_log(avr, AV_LOG_ERROR, "matrix is not set\n");
655 return AVERROR(EINVAL);
658 for (o = 0; o < out_channels; o++)
659 for (i = 0; i < in_channels; i++)
660 matrix[o * stride + i] = avr->mix_matrix[o * in_channels + i];
665 int avresample_set_matrix(AVAudioResampleContext *avr, const double *matrix,
668 int in_channels, out_channels, i, o;
671 return ff_audio_mix_set_matrix(avr->am, matrix, stride);
673 in_channels = av_get_channel_layout_nb_channels(avr->in_channel_layout);
674 out_channels = av_get_channel_layout_nb_channels(avr->out_channel_layout);
676 if ( in_channels <= 0 || in_channels > AVRESAMPLE_MAX_CHANNELS ||
677 out_channels <= 0 || out_channels > AVRESAMPLE_MAX_CHANNELS) {
678 av_log(avr, AV_LOG_ERROR, "Invalid channel layouts\n");
679 return AVERROR(EINVAL);
683 av_freep(&avr->mix_matrix);
684 avr->mix_matrix = av_malloc(in_channels * out_channels *
685 sizeof(*avr->mix_matrix));
686 if (!avr->mix_matrix)
687 return AVERROR(ENOMEM);
689 for (o = 0; o < out_channels; o++)
690 for (i = 0; i < in_channels; i++)
691 avr->mix_matrix[o * in_channels + i] = matrix[o * stride + i];
696 int avresample_set_channel_mapping(AVAudioResampleContext *avr,
697 const int *channel_map)
699 ChannelMapInfo *info = &avr->ch_map_info;
700 int in_channels, ch, i;
702 in_channels = av_get_channel_layout_nb_channels(avr->in_channel_layout);
703 if (in_channels <= 0 || in_channels > AVRESAMPLE_MAX_CHANNELS) {
704 av_log(avr, AV_LOG_ERROR, "Invalid input channel layout\n");
705 return AVERROR(EINVAL);
708 memset(info, 0, sizeof(*info));
709 memset(info->input_map, -1, sizeof(info->input_map));
711 for (ch = 0; ch < in_channels; ch++) {
712 if (channel_map[ch] >= in_channels) {
713 av_log(avr, AV_LOG_ERROR, "Invalid channel map\n");
714 return AVERROR(EINVAL);
716 if (channel_map[ch] < 0) {
717 info->channel_zero[ch] = 1;
718 info->channel_map[ch] = -1;
720 } else if (info->input_map[channel_map[ch]] >= 0) {
721 info->channel_copy[ch] = info->input_map[channel_map[ch]];
722 info->channel_map[ch] = -1;
725 info->channel_map[ch] = channel_map[ch];
726 info->input_map[channel_map[ch]] = ch;
730 /* Fill-in unmapped input channels with unmapped output channels.
731 This is used when remapping during conversion from interleaved to
733 for (ch = 0, i = 0; ch < in_channels && i < in_channels; ch++, i++) {
734 while (ch < in_channels && info->input_map[ch] >= 0)
736 while (i < in_channels && info->channel_map[i] >= 0)
738 if (ch >= in_channels || i >= in_channels)
740 info->input_map[ch] = i;
743 avr->use_channel_map = 1;
747 int avresample_available(AVAudioResampleContext *avr)
749 return av_audio_fifo_size(avr->out_fifo);
752 int avresample_get_out_samples(AVAudioResampleContext *avr, int in_nb_samples)
754 int64_t samples = avresample_get_delay(avr) + (int64_t)in_nb_samples;
756 if (avr->resample_needed) {
757 samples = av_rescale_rnd(samples,
758 avr->out_sample_rate,
763 samples += avresample_available(avr);
765 if (samples > INT_MAX)
766 return AVERROR(EINVAL);
771 int avresample_read(AVAudioResampleContext *avr, uint8_t **output, int nb_samples)
774 return av_audio_fifo_drain(avr->out_fifo, nb_samples);
775 return av_audio_fifo_read(avr->out_fifo, (void**)output, nb_samples);
778 unsigned avresample_version(void)
780 return LIBAVRESAMPLE_VERSION_INT;
783 const char *avresample_license(void)
785 #define LICENSE_PREFIX "libavresample license: "
786 return LICENSE_PREFIX FFMPEG_LICENSE + sizeof(LICENSE_PREFIX) - 1;
789 const char *avresample_configuration(void)
791 return FFMPEG_CONFIGURATION;