lavfi: make ff_framequeue_skip_samples() more useful.

Instead of just updating statistics and leaving the work to the
call site, have it actually do the work.

Also: skip the samples by updating the frame data pointers
instead of moving the samples. More efficient and avoid writing
into shared frames.
Found-By: Muhammad Faiz <mfcc64@gmail.com>
This commit is contained in:
Nicolas George 2017-01-29 10:10:40 +01:00
parent e05d2dd86a
commit 383057f8e7
3 changed files with 33 additions and 13 deletions

View File

@ -1235,13 +1235,7 @@ static int take_samples(AVFilterLink *link, unsigned min, unsigned max,
frame = ff_framequeue_peek(&link->fifo, 0);
av_samples_copy(buf->extended_data, frame->extended_data, p, 0, n,
link->channels, link->format);
frame->nb_samples -= n;
av_samples_copy(frame->extended_data, frame->extended_data, 0, n,
frame->nb_samples, link->channels, link->format);
if (frame->pts != AV_NOPTS_VALUE)
frame->pts += av_rescale_q(n, av_make_q(1, link->sample_rate), link->time_base);
ff_framequeue_update_peeked(&link->fifo, 0);
ff_framequeue_skip_samples(&link->fifo, n);
ff_framequeue_skip_samples(&link->fifo, n, link->time_base);
}
*rframe = buf;

View File

@ -121,3 +121,30 @@ AVFrame *ff_framequeue_peek(FFFrameQueue *fq, size_t idx)
check_consistency(fq);
return b->frame;
}
void ff_framequeue_skip_samples(FFFrameQueue *fq, size_t samples, AVRational time_base)
{
FFFrameBucket *b;
size_t bytes;
int planar, planes, i;
check_consistency(fq);
av_assert1(fq->queued);
b = bucket(fq, 0);
av_assert1(samples < b->frame->nb_samples);
planar = av_sample_fmt_is_planar(b->frame->format);
planes = planar ? b->frame->channels : 1;
bytes = samples * av_get_bytes_per_sample(b->frame->format);
if (!planar)
bytes *= b->frame->channels;
if (b->frame->pts != AV_NOPTS_VALUE)
b->frame->pts += av_rescale_q(samples, av_make_q(1, b->frame->sample_rate), time_base);
b->frame->nb_samples -= samples;
b->frame->linesize[0] -= bytes;
for (i = 0; i < planes; i++)
b->frame->extended_data[i] += bytes;
for (i = 0; i < planes && i < AV_NUM_DATA_POINTERS; i++)
b->frame->data[i] = b->frame->extended_data[i];
fq->total_samples_tail += samples;
ff_framequeue_update_peeked(fq, 0);
}

View File

@ -161,14 +161,13 @@ static inline void ff_framequeue_update_peeked(FFFrameQueue *fq, size_t idx)
}
/**
* Update the sample count in the queue.
* Skip samples from the first frame in the queue.
*
* This function must be used when the first frame was accessed using
* ff_framequeue_peek() and samples were removed from it.
* ff_framequeue_peek() and samples were consumed from it.
* It adapts the data pointers and timestamps of the head frame to account
* for the skipped samples.
*/
static inline void ff_framequeue_skip_samples(FFFrameQueue *fq, size_t n)
{
fq->total_samples_tail += n;
}
void ff_framequeue_skip_samples(FFFrameQueue *fq, size_t samples, AVRational time_base);
#endif /* AVFILTER_FRAMEQUEUE_H */