avresample/resample: remove unused variable
[ffmpeg.git] / libavresample / utils.c
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 #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"
28
29 #include "avresample.h"
30 #include "internal.h"
31 #include "audio_data.h"
32 #include "audio_convert.h"
33 #include "audio_mix.h"
34 #include "resample.h"
35
36 int avresample_open(AVAudioResampleContext *avr)
37 {
38     int ret;
39
40     if (avresample_is_open(avr)) {
41         av_log(avr, AV_LOG_ERROR, "The resampling context is already open.\n");
42         return AVERROR(EINVAL);
43     }
44
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);
51     }
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);
57     }
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;
64
65     /* set resampling parameters */
66     avr->resample_needed   = avr->in_sample_rate != avr->out_sample_rate ||
67                              avr->force_resampling;
68
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));
76         if (max_bps <= 2) {
77             avr->internal_sample_fmt = AV_SAMPLE_FMT_S16P;
78         } else if (avr->mixing_needed) {
79             avr->internal_sample_fmt = AV_SAMPLE_FMT_FLTP;
80         } else {
81             if (max_bps <= 4) {
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;
88                     } else {
89                         /* if one is s32 and the other is s32, s16, or u8, use s32 */
90                         avr->internal_sample_fmt = AV_SAMPLE_FMT_S32P;
91                     }
92                 } else {
93                     /* if one is flt and the other is flt, s16 or u8, use flt */
94                     avr->internal_sample_fmt = AV_SAMPLE_FMT_FLTP;
95                 }
96             } else {
97                 /* if either is dbl, use dbl */
98                 avr->internal_sample_fmt = AV_SAMPLE_FMT_DBLP;
99             }
100         }
101         av_log(avr, AV_LOG_DEBUG, "Using %s as internal sample format\n",
102                av_get_sample_fmt_name(avr->internal_sample_fmt));
103     }
104
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);
110     }
111
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;
115     else
116         avr->in_convert_needed = avr->use_channel_map &&
117                                  !ff_sample_fmt_is_planar(avr->out_sample_fmt, avr->out_channels);
118
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;
121     else
122         avr->out_convert_needed = avr->in_sample_fmt != avr->out_sample_fmt;
123
124     avr->in_copy_needed = !avr->in_convert_needed && (avr->mixing_needed ||
125                           (avr->use_channel_map && avr->resample_needed));
126
127     if (avr->use_channel_map) {
128         if (avr->in_copy_needed) {
129             avr->remap_point = REMAP_IN_COPY;
130             av_log(avr, AV_LOG_TRACE, "remap channels during in_copy\n");
131         } else if (avr->in_convert_needed) {
132             avr->remap_point = REMAP_IN_CONVERT;
133             av_log(avr, AV_LOG_TRACE, "remap channels during in_convert\n");
134         } else if (avr->out_convert_needed) {
135             avr->remap_point = REMAP_OUT_CONVERT;
136             av_log(avr, AV_LOG_TRACE, "remap channels during out_convert\n");
137         } else {
138             avr->remap_point = REMAP_OUT_COPY;
139             av_log(avr, AV_LOG_TRACE, "remap channels during out_copy\n");
140         }
141
142 #ifdef DEBUG
143         {
144             int ch;
145             av_log(avr, AV_LOG_TRACE, "output map: ");
146             if (avr->ch_map_info.do_remap)
147                 for (ch = 0; ch < avr->in_channels; ch++)
148                     av_log(avr, AV_LOG_TRACE, " % 2d", avr->ch_map_info.channel_map[ch]);
149             else
150                 av_log(avr, AV_LOG_TRACE, "n/a");
151             av_log(avr, AV_LOG_TRACE, "\n");
152             av_log(avr, AV_LOG_TRACE, "copy map:   ");
153             if (avr->ch_map_info.do_copy)
154                 for (ch = 0; ch < avr->in_channels; ch++)
155                     av_log(avr, AV_LOG_TRACE, " % 2d", avr->ch_map_info.channel_copy[ch]);
156             else
157                 av_log(avr, AV_LOG_TRACE, "n/a");
158             av_log(avr, AV_LOG_TRACE, "\n");
159             av_log(avr, AV_LOG_TRACE, "zero map:   ");
160             if (avr->ch_map_info.do_zero)
161                 for (ch = 0; ch < avr->in_channels; ch++)
162                     av_log(avr, AV_LOG_TRACE, " % 2d", avr->ch_map_info.channel_zero[ch]);
163             else
164                 av_log(avr, AV_LOG_TRACE, "n/a");
165             av_log(avr, AV_LOG_TRACE, "\n");
166             av_log(avr, AV_LOG_TRACE, "input map:  ");
167             for (ch = 0; ch < avr->in_channels; ch++)
168                 av_log(avr, AV_LOG_TRACE, " % 2d", avr->ch_map_info.input_map[ch]);
169             av_log(avr, AV_LOG_TRACE, "\n");
170         }
171 #endif
172     } else
173         avr->remap_point = REMAP_NONE;
174
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,
179                                              "in_buffer");
180         if (!avr->in_buffer) {
181             ret = AVERROR(EINVAL);
182             goto error;
183         }
184     }
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);
191             goto error;
192         }
193     }
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);
199             goto error;
200         }
201     }
202     avr->out_fifo = av_audio_fifo_alloc(avr->out_sample_fmt, avr->out_channels,
203                                         1024);
204     if (!avr->out_fifo) {
205         ret = AVERROR(ENOMEM);
206         goto error;
207     }
208
209     /* setup contexts */
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,
213                                             avr->in_sample_rate,
214                                             avr->remap_point == REMAP_IN_CONVERT);
215         if (!avr->ac_in) {
216             ret = AVERROR(ENOMEM);
217             goto error;
218         }
219     }
220     if (avr->out_convert_needed) {
221         enum AVSampleFormat src_fmt;
222         if (avr->in_convert_needed)
223             src_fmt = avr->internal_sample_fmt;
224         else
225             src_fmt = avr->in_sample_fmt;
226         avr->ac_out = ff_audio_convert_alloc(avr, avr->out_sample_fmt, src_fmt,
227                                              avr->out_channels,
228                                              avr->out_sample_rate,
229                                              avr->remap_point == REMAP_OUT_CONVERT);
230         if (!avr->ac_out) {
231             ret = AVERROR(ENOMEM);
232             goto error;
233         }
234     }
235     if (avr->resample_needed) {
236         avr->resample = ff_audio_resample_init(avr);
237         if (!avr->resample) {
238             ret = AVERROR(ENOMEM);
239             goto error;
240         }
241     }
242     if (avr->mixing_needed) {
243         avr->am = ff_audio_mix_alloc(avr);
244         if (!avr->am) {
245             ret = AVERROR(ENOMEM);
246             goto error;
247         }
248     }
249
250     return 0;
251
252 error:
253     avresample_close(avr);
254     return ret;
255 }
256
257 int avresample_is_open(AVAudioResampleContext *avr)
258 {
259     return !!avr->out_fifo;
260 }
261
262 void avresample_close(AVAudioResampleContext *avr)
263 {
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);
274
275     avr->use_channel_map = 0;
276 }
277
278 void avresample_free(AVAudioResampleContext **avr)
279 {
280     if (!*avr)
281         return;
282     avresample_close(*avr);
283     av_opt_free(*avr);
284     av_freep(avr);
285 }
286
287 static int handle_buffered_output(AVAudioResampleContext *avr,
288                                   AudioData *output, AudioData *converted)
289 {
290     int ret;
291
292     if (!output || av_audio_fifo_size(avr->out_fifo) > 0 ||
293         (converted && output->allocated_samples < converted->nb_samples)) {
294         if (converted) {
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_log(avr, AV_LOG_TRACE, "[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);
301             if (ret < 0)
302                 return ret;
303         }
304
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_log(avr, AV_LOG_TRACE, "[FIFO] read from out_fifo to output\n");
309             av_log(avr, AV_LOG_TRACE, "[end conversion]\n");
310             return ff_audio_data_read_from_fifo(avr->out_fifo, output,
311                                                 output->allocated_samples);
312         }
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_log(avr, AV_LOG_TRACE, "[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);
321         if (ret < 0)
322             return ret;
323         av_log(avr, AV_LOG_TRACE, "[end conversion]\n");
324         return output->nb_samples;
325     }
326     av_log(avr, AV_LOG_TRACE, "[end conversion]\n");
327     return 0;
328 }
329
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)
334 {
335     AudioData input_buffer;
336     AudioData output_buffer;
337     AudioData *current_buffer;
338     int ret, direct_output;
339
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);
345     }
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);
350     }
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);
355     }
356
357     av_log(avr, AV_LOG_TRACE, "[start conversion]\n");
358
359     /* initialize output_buffer with output data */
360     direct_output = output && av_audio_fifo_size(avr->out_fifo) == 0;
361     if (output) {
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");
365         if (ret < 0)
366             return ret;
367         output_buffer.nb_samples = 0;
368     }
369
370     if (input) {
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");
375         if (ret < 0)
376             return ret;
377         current_buffer = &input_buffer;
378
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_log(avr, AV_LOG_TRACE, "[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);
387             if (ret < 0)
388                 return ret;
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_log(avr, AV_LOG_TRACE, "[copy] %s to out_buffer\n", current_buffer->name);
396             ret = ff_audio_data_copy(avr->out_buffer, current_buffer,
397                                      &avr->ch_map_info);
398             if (ret < 0)
399                 return ret;
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
403                applicable */
404             if (avr->in_convert_needed) {
405                 ret = ff_audio_data_realloc(avr->in_buffer,
406                                             current_buffer->nb_samples);
407                 if (ret < 0)
408                     return ret;
409                 av_log(avr, AV_LOG_TRACE, "[convert] %s to in_buffer\n", current_buffer->name);
410                 ret = ff_audio_convert(avr->ac_in, avr->in_buffer,
411                                        current_buffer);
412                 if (ret < 0)
413                     return ret;
414             } else {
415                 av_log(avr, AV_LOG_TRACE, "[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);
419                 if (ret < 0)
420                     return ret;
421             }
422             ff_audio_data_set_channels(avr->in_buffer, avr->in_channels);
423             if (avr->downmix_needed) {
424                 av_log(avr, AV_LOG_TRACE, "[downmix] in_buffer\n");
425                 ret = ff_audio_mix(avr->am, avr->in_buffer);
426                 if (ret < 0)
427                     return ret;
428             }
429             current_buffer = avr->in_buffer;
430         }
431     } else {
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,
435                                           NULL);
436         current_buffer = NULL;
437     }
438
439     if (avr->resample_needed) {
440         AudioData *resample_out;
441
442         if (!avr->out_convert_needed && direct_output && out_samples > 0)
443             resample_out = &output_buffer;
444         else
445             resample_out = avr->resample_out_buffer;
446         av_log(avr, AV_LOG_TRACE, "[resample] %s to %s\n",
447                 current_buffer ? current_buffer->name : "null",
448                 resample_out->name);
449         ret = ff_audio_resample(avr->resample, resample_out,
450                                 current_buffer);
451         if (ret < 0)
452             return ret;
453
454         /* if resampling did not produce any samples, just return 0 */
455         if (resample_out->nb_samples == 0) {
456             av_log(avr, AV_LOG_TRACE, "[end conversion]\n");
457             return 0;
458         }
459
460         current_buffer = resample_out;
461     }
462
463     if (avr->upmix_needed) {
464         av_log(avr, AV_LOG_TRACE, "[upmix] %s\n", current_buffer->name);
465         ret = ff_audio_mix(avr->am, current_buffer);
466         if (ret < 0)
467             return ret;
468     }
469
470     /* if we resampled or upmixed directly to output, return here */
471     if (current_buffer == &output_buffer) {
472         av_log(avr, AV_LOG_TRACE, "[end conversion]\n");
473         return current_buffer->nb_samples;
474     }
475
476     if (avr->out_convert_needed) {
477         if (direct_output && out_samples >= current_buffer->nb_samples) {
478             /* convert directly to output */
479             av_log(avr, AV_LOG_TRACE, "[convert] %s to output\n", current_buffer->name);
480             ret = ff_audio_convert(avr->ac_out, &output_buffer, current_buffer);
481             if (ret < 0)
482                 return ret;
483
484             av_log(avr, AV_LOG_TRACE, "[end conversion]\n");
485             return output_buffer.nb_samples;
486         } else {
487             ret = ff_audio_data_realloc(avr->out_buffer,
488                                         current_buffer->nb_samples);
489             if (ret < 0)
490                 return ret;
491             av_log(avr, AV_LOG_TRACE, "[convert] %s to out_buffer\n", current_buffer->name);
492             ret = ff_audio_convert(avr->ac_out, avr->out_buffer,
493                                    current_buffer);
494             if (ret < 0)
495                 return ret;
496             current_buffer = avr->out_buffer;
497         }
498     }
499
500     return handle_buffered_output(avr, output ? &output_buffer : NULL,
501                                   current_buffer);
502 }
503
504 int avresample_config(AVAudioResampleContext *avr, AVFrame *out, AVFrame *in)
505 {
506     if (avresample_is_open(avr)) {
507         avresample_close(avr);
508     }
509
510     if (in) {
511         avr->in_channel_layout  = in->channel_layout;
512         avr->in_sample_rate     = in->sample_rate;
513         avr->in_sample_fmt      = in->format;
514     }
515
516     if (out) {
517         avr->out_channel_layout = out->channel_layout;
518         avr->out_sample_rate    = out->sample_rate;
519         avr->out_sample_fmt     = out->format;
520     }
521
522     return 0;
523 }
524
525 static int config_changed(AVAudioResampleContext *avr,
526                           AVFrame *out, AVFrame *in)
527 {
528     int ret = 0;
529
530     if (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;
535         }
536     }
537
538     if (out) {
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;
543         }
544     }
545
546     return ret;
547 }
548
549 static inline int convert_frame(AVAudioResampleContext *avr,
550                                 AVFrame *out, AVFrame *in)
551 {
552     int ret;
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;
556
557     if (out) {
558         out_data       = out->extended_data;
559         out_linesize   = out->linesize[0];
560         out_nb_samples = out->nb_samples;
561     }
562
563     if (in) {
564         in_data       = in->extended_data;
565         in_linesize   = in->linesize[0];
566         in_nb_samples = in->nb_samples;
567     }
568
569     ret = avresample_convert(avr, out_data, out_linesize,
570                              out_nb_samples,
571                              in_data, in_linesize,
572                              in_nb_samples);
573
574     if (ret < 0) {
575         if (out)
576             out->nb_samples = 0;
577         return ret;
578     }
579
580     if (out)
581         out->nb_samples = ret;
582
583     return 0;
584 }
585
586 static inline int available_samples(AVFrame *out)
587 {
588     int samples;
589     int bytes_per_sample = av_get_bytes_per_sample(out->format);
590     if (!bytes_per_sample)
591         return AVERROR(EINVAL);
592
593     samples = out->linesize[0] / bytes_per_sample;
594     if (av_sample_fmt_is_planar(out->format)) {
595         return samples;
596     } else {
597         int channels = av_get_channel_layout_nb_channels(out->channel_layout);
598         return samples / channels;
599     }
600 }
601
602 int avresample_convert_frame(AVAudioResampleContext *avr,
603                              AVFrame *out, AVFrame *in)
604 {
605     int ret, setup = 0;
606
607     if (!avresample_is_open(avr)) {
608         if ((ret = avresample_config(avr, out, in)) < 0)
609             return ret;
610         if ((ret = avresample_open(avr)) < 0)
611             return ret;
612         setup = 1;
613     } else {
614         // return as is or reconfigure for input changes?
615         if ((ret = config_changed(avr, out, in)))
616             return ret;
617     }
618
619     if (out) {
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) {
623                 if (setup)
624                     avresample_close(avr);
625                 return ret;
626             }
627         } else {
628             if (!out->nb_samples)
629                 out->nb_samples = available_samples(out);
630         }
631     }
632
633     return convert_frame(avr, out, in);
634 }
635
636 int avresample_get_matrix(AVAudioResampleContext *avr, double *matrix,
637                           int stride)
638 {
639     int in_channels, out_channels, i, o;
640
641     if (avr->am)
642         return ff_audio_mix_get_matrix(avr->am, matrix, stride);
643
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);
646
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);
651     }
652
653     if (!avr->mix_matrix) {
654         av_log(avr, AV_LOG_ERROR, "matrix is not set\n");
655         return AVERROR(EINVAL);
656     }
657
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];
661
662     return 0;
663 }
664
665 int avresample_set_matrix(AVAudioResampleContext *avr, const double *matrix,
666                           int stride)
667 {
668     int in_channels, out_channels, i, o;
669
670     if (avr->am)
671         return ff_audio_mix_set_matrix(avr->am, matrix, stride);
672
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);
675
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);
680     }
681
682     if (avr->mix_matrix)
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);
688
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];
692
693     return 0;
694 }
695
696 int avresample_set_channel_mapping(AVAudioResampleContext *avr,
697                                    const int *channel_map)
698 {
699     ChannelMapInfo *info = &avr->ch_map_info;
700     int in_channels, ch, i;
701
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);
706     }
707
708     memset(info, 0, sizeof(*info));
709     memset(info->input_map, -1, sizeof(info->input_map));
710
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);
715         }
716         if (channel_map[ch] < 0) {
717             info->channel_zero[ch] =  1;
718             info->channel_map[ch]  = -1;
719             info->do_zero          =  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;
723             info->do_copy          =  1;
724         } else {
725             info->channel_map[ch]            = channel_map[ch];
726             info->input_map[channel_map[ch]] = ch;
727             info->do_remap                   =  1;
728         }
729     }
730     /* Fill-in unmapped input channels with unmapped output channels.
731        This is used when remapping during conversion from interleaved to
732        planar format. */
733     for (ch = 0, i = 0; ch < in_channels && i < in_channels; ch++, i++) {
734         while (ch < in_channels && info->input_map[ch] >= 0)
735             ch++;
736         while (i < in_channels && info->channel_map[i] >= 0)
737             i++;
738         if (ch >= in_channels || i >= in_channels)
739             break;
740         info->input_map[ch] = i;
741     }
742
743     avr->use_channel_map = 1;
744     return 0;
745 }
746
747 int avresample_available(AVAudioResampleContext *avr)
748 {
749     return av_audio_fifo_size(avr->out_fifo);
750 }
751
752 int avresample_get_out_samples(AVAudioResampleContext *avr, int in_nb_samples)
753 {
754     int64_t samples = avresample_get_delay(avr) + (int64_t)in_nb_samples;
755
756     if (avr->resample_needed) {
757         samples = av_rescale_rnd(samples,
758                                  avr->out_sample_rate,
759                                  avr->in_sample_rate,
760                                  AV_ROUND_UP);
761     }
762
763     samples += avresample_available(avr);
764
765     if (samples > INT_MAX)
766         return AVERROR(EINVAL);
767
768     return samples;
769 }
770
771 int avresample_read(AVAudioResampleContext *avr, uint8_t **output, int nb_samples)
772 {
773     if (!output)
774         return av_audio_fifo_drain(avr->out_fifo, nb_samples);
775     return av_audio_fifo_read(avr->out_fifo, (void**)output, nb_samples);
776 }
777
778 unsigned avresample_version(void)
779 {
780     return LIBAVRESAMPLE_VERSION_INT;
781 }
782
783 const char *avresample_license(void)
784 {
785 #define LICENSE_PREFIX "libavresample license: "
786     return LICENSE_PREFIX FFMPEG_LICENSE + sizeof(LICENSE_PREFIX) - 1;
787 }
788
789 const char *avresample_configuration(void)
790 {
791     return FFMPEG_CONFIGURATION;
792 }