FFmpeg: libavcodec/audio_frame_queue.c Source File

FFmpeg

[フレーム]

libavcodec

audio_frame_queue.c

Go to the documentation of this file.

1 /*

2 * Audio Frame Queue

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 */

22 #include "libavutil/attributes.h"

23 #include "libavutil/common.h"

24 #include "audio_frame_queue.h"

25 #include "internal.h"

26 #include "libavutil/avassert.h"

28 av_cold void ff_af_queue_init(AVCodecContext *avctx, AudioFrameQueue *afq)

29 {

30 afq->avctx = avctx;

31 afq->remaining_delay = avctx->delay;

32 afq->remaining_samples = avctx->delay;

33 afq->frame_count = 0;

34 }

36 void ff_af_queue_close(AudioFrameQueue *afq)

37 {

38 if(afq->frame_count)

39 av_log(afq->avctx, AV_LOG_WARNING, "%d frames left in the queue on closing\n", afq->frame_count);

40 av_freep(&afq->frames);

41 memset(afq, 0, sizeof(*afq));

42 }

44 int ff_af_queue_add(AudioFrameQueue *afq, const AVFrame *f)

45 {

46 AudioFrame *new = av_fast_realloc(afq->frames, &afq->frame_alloc, sizeof(*afq->frames)*(afq->frame_count+1));

47 if(!new)

48 return AVERROR(ENOMEM);

49 afq->frames = new;

50 new += afq->frame_count;

52 /* get frame parameters */

53 new->duration = f->nb_samples;

54 new->duration += afq->remaining_delay;

55 if (f->pts != AV_NOPTS_VALUE) {

56 new->pts = av_rescale_q(f->pts,

57 afq->avctx->time_base,

58 (AVRational){ 1, afq->avctx->sample_rate });

59 new->pts -= afq->remaining_delay;

60 if(afq->frame_count && new[-1].pts >= new->pts)

61 av_log(afq->avctx, AV_LOG_WARNING, "Queue input is backward in time\n");

62 } else {

63 new->pts = AV_NOPTS_VALUE;

64 }

65 afq->remaining_delay = 0;

67 /* add frame sample count */

68 afq->remaining_samples += f->nb_samples;

70 afq->frame_count++;

72 return 0;

73 }

75 void ff_af_queue_remove(AudioFrameQueue *afq, int nb_samples, int64_t *pts,

76 int *duration)

77 {

78 int64_t out_pts = AV_NOPTS_VALUE;

79 int removed_samples = 0;

80 int i;

82 if (afq->frame_count || afq->frame_alloc) {

83 if (afq->frames->pts != AV_NOPTS_VALUE)

84 out_pts = afq->frames->pts;

85 }

86 if(!afq->frame_count)

87 av_log(afq->avctx, AV_LOG_WARNING, "Trying to remove %d samples, but the queue is empty\n", nb_samples);

88 if (pts)

89 *pts = ff_samples_to_time_base(afq->avctx, out_pts);

91 for(i=0; nb_samples && i<afq->frame_count; i++){

92 int n= FFMIN(afq->frames[i].duration, nb_samples);

93 afq->frames[i].duration -= n;

94 nb_samples -= n;

95 removed_samples += n;

96 if(afq->frames[i].pts != AV_NOPTS_VALUE)

97 afq->frames[i].pts += n;

98 }

99 afq->remaining_samples -= removed_samples;

100 i -= i && afq->frames[i-1].duration;

101 memmove(afq->frames, afq->frames + i, sizeof(*afq->frames) * (afq->frame_count - i));

102 afq->frame_count -= i;

103

104 if(nb_samples){

105 av_assert0(!afq->frame_count);

106 av_assert0(afq->remaining_samples == afq->remaining_delay);

107 if(afq->frames && afq->frames[0].pts != AV_NOPTS_VALUE)

108 afq->frames[0].pts += nb_samples;

109 av_log(afq->avctx, AV_LOG_DEBUG, "Trying to remove %d more samples than there are in the queue\n", nb_samples);

110 }

111 if (duration)

112 *duration = ff_samples_to_time_base(afq->avctx, removed_samples);

113 }

Generated on Sun Jul 20 2014 23:05:44 for FFmpeg by doxygen 1.8.2