highperfocused/ffmpeg
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

avfilter: take_samples: do not directly return frame when samples are skipped

Browse Source 
Modifying data pointer when skipping samples may make it unaligned.
Workaround for Ticket6349.

This should fix the crash of ticket's testcase and a crash/regression
with avxsynth (reported by Michael Niedermayer).

Also change frame->nb_samples < max to frame->nb_samples <= max.
This improves performance. Benchmark:
./ffmpeg -filter_complex "aevalsrc=0:n=1166,firequalizer=fixed=on" -f null null
old:
  25767 decicycles in take_samples,    1023 runs,      1 skips
  25422 decicycles in take_samples,    2047 runs,      1 skips
  25181 decicycles in take_samples,    4095 runs,      1 skips
  24904 decicycles in take_samples,    8191 runs,      1 skips

new:
    550 decicycles in take_samples,    1024 runs,      0 skips
    548 decicycles in take_samples,    2048 runs,      0 skips
    545 decicycles in take_samples,    4096 runs,      0 skips
    544 decicycles in take_samples,    8192 runs,      0 skips

Reviewed-by: Nicolas George <george@nsup.org>
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Muhammad Faiz <mfcc64@gmail.com>
This commit is contained in:
Muhammad Faiz
2017-05-18 20:10:47 +07:00
parent f20161d899
commit fc3a03fcf9
3 changed files with 14 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
libavfilter/framequeue.c
View File

@ -107,6 +107,7 @@ AVFrame *ff_framequeue_take(FFFrameQueue *fq)
fq->tail &= fq->allocated - 1;
fq->total_frames_tail++;
fq->total_samples_tail += b->frame->nb_samples;
fq->samples_skipped = 0;
check_consistency(fq);
return b->frame;
}
@ -146,5 +147,6 @@ void ff_framequeue_skip_samples(FFFrameQueue *fq, size_t samples, AVRational tim
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;
fq->samples_skipped = 1;
ff_framequeue_update_peeked(fq, 0);
}