FFmpeg/libavfilter/framequeue.c
Nicolas George 383057f8e7 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>
2017-01-29 18:53:11 +01:00

151 lines
4.4 KiB
C

/*
* Generic frame queue
* Copyright (c) 2016 Nicolas George
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/avassert.h"
#include "framequeue.h"
static inline FFFrameBucket *bucket(FFFrameQueue *fq, size_t idx)
{
return &fq->queue[(fq->tail + idx) & (fq->allocated - 1)];
}
void ff_framequeue_global_init(FFFrameQueueGlobal *fqg)
{
}
static void check_consistency(FFFrameQueue *fq)
{
#if defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
uint64_t nb_samples = 0;
size_t i;
av_assert0(fq->queued == fq->total_frames_head - fq->total_frames_tail);
for (i = 0; i < fq->queued; i++)
nb_samples += bucket(fq, i)->frame->nb_samples;
av_assert0(nb_samples == fq->total_samples_head - fq->total_samples_tail);
#endif
}
void ff_framequeue_init(FFFrameQueue *fq, FFFrameQueueGlobal *fqg)
{
fq->queue = &fq->first_bucket;
fq->allocated = 1;
}
void ff_framequeue_free(FFFrameQueue *fq)
{
while (fq->queued) {
AVFrame *frame = ff_framequeue_take(fq);
av_frame_free(&frame);
}
if (fq->queue != &fq->first_bucket)
av_freep(&fq->queue);
}
int ff_framequeue_add(FFFrameQueue *fq, AVFrame *frame)
{
FFFrameBucket *b;
check_consistency(fq);
if (fq->queued == fq->allocated) {
if (fq->allocated == 1) {
size_t na = 8;
FFFrameBucket *nq = av_realloc_array(NULL, na, sizeof(*nq));
if (!nq)
return AVERROR(ENOMEM);
nq[0] = fq->queue[0];
fq->queue = nq;
fq->allocated = na;
} else {
size_t na = fq->allocated << 1;
FFFrameBucket *nq = av_realloc_array(fq->queue, na, sizeof(*nq));
if (!nq)
return AVERROR(ENOMEM);
if (fq->tail + fq->queued > fq->allocated)
memmove(nq + fq->allocated, nq,
(fq->tail + fq->queued - fq->allocated) * sizeof(*nq));
fq->queue = nq;
fq->allocated = na;
}
}
b = bucket(fq, fq->queued);
b->frame = frame;
fq->queued++;
fq->total_frames_head++;
fq->total_samples_head += frame->nb_samples;
check_consistency(fq);
return 0;
}
AVFrame *ff_framequeue_take(FFFrameQueue *fq)
{
FFFrameBucket *b;
check_consistency(fq);
av_assert1(fq->queued);
b = bucket(fq, 0);
fq->queued--;
fq->tail++;
fq->tail &= fq->allocated - 1;
fq->total_frames_tail++;
fq->total_samples_tail += b->frame->nb_samples;
check_consistency(fq);
return b->frame;
}
AVFrame *ff_framequeue_peek(FFFrameQueue *fq, size_t idx)
{
FFFrameBucket *b;
check_consistency(fq);
av_assert1(idx < fq->queued);
b = bucket(fq, 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);
}