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Code Issues Releases Activity

lavc: pad last audio frame with silence when needed.

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This commit is contained in:
Anton Khirnov 2012-05-07 13:55:03 +02:00
parent 6d7f617700
commit a5117a2444
6 changed files with 80 additions and 16 deletions
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8
avconv.c
View File

@ -2048,14 +2048,6 @@ static void flush_encoders(void)
av_fifo_generic_read(ost->fifo, audio_buf, fifo_bytes, NULL);
/* pad last frame with silence if needed */
if (!(enc->codec->capabilities & CODEC_CAP_SMALL_LAST_FRAME)) {
frame_bytes = enc->frame_size * enc->channels *
av_get_bytes_per_sample(enc->sample_fmt);
if (allocated_audio_buf_size < frame_bytes)
exit_program(1);
generate_silence(audio_buf+fifo_bytes, enc->sample_fmt, frame_bytes - fifo_bytes);
}
encode_audio_frame(os, ost, audio_buf, frame_bytes);
} else {
/* flush encoder with NULL frames until it is done

6
doc/APIchanges
View File

@ -13,6 +13,12 @@ libavutil: 2011-04-18
API changes, most recent first:
2012-xx-xx - xxxxxxx - lavc 54.13.1
For audio formats with fixed frame size, the last frame
no longer needs to be padded with silence, libavcodec
will handle this internally (effectively all encoders
behave as if they had CODEC_CAP_SMALL_LAST_FRAME set).
2012-xx-xx - xxxxxxx - lavc 54.13.0 - avcodec.h
Add sample_rate and channel_layout fields to AVFrame.

10
libavcodec/avcodec.h
View File

@ -3860,15 +3860,11 @@ int attribute_deprecated avcodec_encode_audio(AVCodecContext *avctx,
* @param[in] frame AVFrame containing the raw audio data to be encoded.
* May be NULL when flushing an encoder that has the
* CODEC_CAP_DELAY capability set.
* There are 2 codec capabilities that affect the allowed
* values of frame->nb_samples.
* If CODEC_CAP_SMALL_LAST_FRAME is set, then only the final
* frame may be smaller than avctx->frame_size, and all other
* frames must be equal to avctx->frame_size.
* If CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
* can have any number of samples.
* If neither is set, frame->nb_samples must be equal to
* avctx->frame_size for all frames.
* If it is not set, frame->nb_samples must be equal to
* avctx->frame_size for all frames except the last.
* The final frame may be smaller than avctx->frame_size.
* @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
* output packet is non-empty, and to 0 if it is
* empty. If the function returns an error, the

6
libavcodec/internal.h
View File

@ -70,6 +70,12 @@ typedef struct AVCodecInternal {
*/
int sample_count;
#endif
/**
* An audio frame with less than required samples has been submitted and
* padded with silence. Reject all subsequent frames.
*/
int last_audio_frame;
} AVCodecInternal;
struct AVCodecDefault {

64
libavcodec/utils.c
View File

@ -857,11 +857,58 @@ int ff_alloc_packet(AVPacket *avpkt, int size)
}
}
/**
* Pad last frame with silence.
*/
static int pad_last_frame(AVCodecContext *s, AVFrame **dst, const AVFrame *src)
{
AVFrame *frame = NULL;
uint8_t *buf = NULL;
int ret;
if (!(frame = avcodec_alloc_frame()))
return AVERROR(ENOMEM);
*frame = *src;
if ((ret = av_samples_get_buffer_size(&frame->linesize[0], s->channels,
s->frame_size, s->sample_fmt, 0)) < 0)
goto fail;
if (!(buf = av_malloc(ret))) {
ret = AVERROR(ENOMEM);
goto fail;
}
frame->nb_samples = s->frame_size;
if ((ret = avcodec_fill_audio_frame(frame, s->channels, s->sample_fmt,
buf, ret, 0)) < 0)
goto fail;
if ((ret = av_samples_copy(frame->extended_data, src->extended_data, 0, 0,
src->nb_samples, s->channels, s->sample_fmt)) < 0)
goto fail;
if ((ret = av_samples_set_silence(frame->extended_data, src->nb_samples,
frame->nb_samples - src->nb_samples,
s->channels, s->sample_fmt)) < 0)
goto fail;
*dst = frame;
return 0;
fail:
if (frame->extended_data != frame->data)
av_freep(&frame->extended_data);
av_freep(&buf);
av_freep(&frame);
return ret;
}
int attribute_align_arg avcodec_encode_audio2(AVCodecContext *avctx,
AVPacket *avpkt,
const AVFrame *frame,
int *got_packet_ptr)
{
AVFrame *padded_frame = NULL;
int ret;
int user_packet = !!avpkt->data;
@ -879,6 +926,16 @@ int attribute_align_arg avcodec_encode_audio2(AVCodecContext *avctx,
if (frame->nb_samples > avctx->frame_size)
return AVERROR(EINVAL);
} else if (!(avctx->codec->capabilities & CODEC_CAP_VARIABLE_FRAME_SIZE)) {
if (frame->nb_samples < avctx->frame_size &&
!avctx->internal->last_audio_frame) {
ret = pad_last_frame(avctx, &padded_frame, frame);
if (ret < 0)
return ret;
frame = padded_frame;
avctx->internal->last_audio_frame = 1;
}
if (frame->nb_samples != avctx->frame_size)
return AVERROR(EINVAL);
}
@ -919,6 +976,13 @@ int attribute_align_arg avcodec_encode_audio2(AVCodecContext *avctx,
here to simplify things */
avpkt->flags |= AV_PKT_FLAG_KEY;
if (padded_frame) {
av_freep(&padded_frame->data[0]);
if (padded_frame->extended_data != padded_frame->data)
av_freep(&padded_frame->extended_data);
av_freep(&padded_frame);
}
return ret;
}

2
libavcodec/version.h
View File

@ -28,7 +28,7 @@
#define LIBAVCODEC_VERSION_MAJOR 54
#define LIBAVCODEC_VERSION_MINOR 13
#define LIBAVCODEC_VERSION_MICRO 0
#define LIBAVCODEC_VERSION_MICRO 1
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
LIBAVCODEC_VERSION_MINOR, \