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audio_frame_queue.c
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1 /*
2  * Audio Frame Queue
3  * Copyright (c) 2012 Justin Ruggles
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "libavutil/common.h"
23 #include "audio_frame_queue.h"
24 #include "internal.h"
25 #include "libavutil/avassert.h"
26 
27 void ff_af_queue_init(AVCodecContext *avctx, AudioFrameQueue *afq)
28 {
29  afq->avctx = avctx;
30  afq->remaining_delay = avctx->delay;
31  afq->remaining_samples = avctx->delay;
32  afq->frame_count = 0;
33 }
34 
35 void ff_af_queue_close(AudioFrameQueue *afq)
36 {
37  if(afq->frame_count)
38  av_log(afq->avctx, AV_LOG_WARNING, "%d frames left in the queue on closing\n", afq->frame_count);
39  av_freep(&afq->frames);
40  memset(afq, 0, sizeof(*afq));
41 }
42 
43 int ff_af_queue_add(AudioFrameQueue *afq, const AVFrame *f)
44 {
45  AudioFrame *new = av_fast_realloc(afq->frames, &afq->frame_alloc, sizeof(*afq->frames)*(afq->frame_count+1));
46  if(!new)
47  return AVERROR(ENOMEM);
48  afq->frames = new;
49  new += afq->frame_count;
50 
51  /* get frame parameters */
52  new->duration = f->nb_samples;
53  new->duration += afq->remaining_delay;
54  if (f->pts != AV_NOPTS_VALUE) {
55  new->pts = av_rescale_q(f->pts,
56  afq->avctx->time_base,
57  (AVRational){ 1, afq->avctx->sample_rate });
58  new->pts -= afq->remaining_delay;
59  if(afq->frame_count && new[-1].pts >= new->pts)
60  av_log(afq->avctx, AV_LOG_WARNING, "Que input is backward in time\n");
61  } else {
62  new->pts = AV_NOPTS_VALUE;
63  }
64  afq->remaining_delay = 0;
65 
66  /* add frame sample count */
67  afq->remaining_samples += f->nb_samples;
68 
69  afq->frame_count++;
70 
71  return 0;
72 }
73 
74 void ff_af_queue_remove(AudioFrameQueue *afq, int nb_samples, int64_t *pts,
75  int *duration)
76 {
77  int64_t out_pts = AV_NOPTS_VALUE;
78  int removed_samples = 0;
79  int i;
80 
81  if (afq->frame_count || afq->frame_alloc) {
82  if (afq->frames->pts != AV_NOPTS_VALUE)
83  out_pts = afq->frames->pts;
84  }
85  if(!afq->frame_count)
86  av_log(afq->avctx, AV_LOG_WARNING, "Trying to remove %d samples, but the queue is empty\n", nb_samples);
87  if (pts)
88  *pts = ff_samples_to_time_base(afq->avctx, out_pts);
89 
90  for(i=0; nb_samples && i<afq->frame_count; i++){
91  int n= FFMIN(afq->frames[i].duration, nb_samples);
92  afq->frames[i].duration -= n;
93  nb_samples -= n;
94  removed_samples += n;
95  if(afq->frames[i].pts != AV_NOPTS_VALUE)
96  afq->frames[i].pts += n;
97  }
98  afq->remaining_samples -= removed_samples;
99  i -= i && afq->frames[i-1].duration;
100  memmove(afq->frames, afq->frames + i, sizeof(*afq->frames) * (afq->frame_count - i));
101  afq->frame_count -= i;
102 
103  if(nb_samples){
104  av_assert0(!afq->frame_count);
105  av_assert0(afq->remaining_samples == afq->remaining_delay);
106  if(afq->frames && afq->frames[0].pts != AV_NOPTS_VALUE)
107  afq->frames[0].pts += nb_samples;
108  av_log(afq->avctx, AV_LOG_DEBUG, "Trying to remove %d more samples than there are in the queue\n", nb_samples);
109  }
110  if (duration)
111  *duration = ff_samples_to_time_base(afq->avctx, removed_samples);
112 }
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