[FFmpeg-trac] #7388(ffmpeg:new): Using -threads causes distorted output in some frames
FFmpeg
trac at avcodec.org
Wed Aug 29 16:50:52 EEST 2018
#7388: Using -threads causes distorted output in some frames
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Reporter: jluther | Type: defect
Status: new | Priority: normal
Component: ffmpeg | Version: git-master
Keywords: | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
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Summary:
I am encoding a 1080p H.264 Main Profile MP4 source to 180p scaled
Baseline MP4 using CRF rate control.
When I run my FFmpeg command with a -threads value greater than 8, there
are heavily distorted frames in the lower half of the output at around
00:00:01 into playback.
When -threads param is removed from the command, the frames are not
distorted.
Reproducing:
Behavior is reproducible on Mac 10.13.6 using FFmpeg built from August
28th Git master.
However, it is only reproducible with this one video. Other samples encode
fine.
Command that produces the distorted output:
ffmpeg -y -report -i jluther-threads-bug-report-source.mp4 -pix_fmt
yuv420p -vsync cfr -r 25 -filter:v '[in] scale=320:-2 [out]' -c:v libx264
-profile:v baseline -x264opts keyint=100:vbv-maxrate=300:vbv-bufsize=300
-threads 12 -an out/with-12-threads.mp4
Console output and -report log are in attached archive.
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Ticket URL: <https://trac.ffmpeg.org/ticket/7388>
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