[FFmpeg-trac] #9476(ffmpeg:new): Unstable outputs ffmpeg (the second one)

[FFmpeg]

#9476: Unstable outputs ffmpeg (the second one)
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             Reporter:  Shaohua Li  |                     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 of the bug: For some inputs, ffmpeg's output file will change per
 run. I have reported a similar issue before (see
 https://trac.ffmpeg.org/ticket/9272). But that one is a threading issue
 and ''-threads 1'' makes the issue disappear. However, this seems not to
 be a threading issue since with ''-threads 1'' the output files still
 change per run.
 Compiler: gcc11
 How to reproduce: (run the following command several times, and check the
 size of output.mp4 in each run. )
 {{{
 % ffmpeg -threads 1 -y -i input.avi -f mp4 output.mp4
 ffmpeg version N-104353-g2c734a8496 Copyright (c) 2000-2021 the FFmpeg
 developers
   built with gcc 11 (Ubuntu 11.1.0-1ubuntu1~20.04)
   configuration: --cc=/afl_diff_rand/afl_diff/compilers/gcc11-base/afl-gcc
 --cxx=/afl_diff_rand/afl_diff/compilers/gcc11-base/afl-g++
 --ld='/afl_diff_rand/afl_diff/compilers/gcc11-base/afl-g++ -fno-
 sanitize=vptr -fno-sanitize=vptr -fno-sanitize=vptr -fno-sanitize=vptr
 -fno-sanitize=vptr -fno-sanitize=vptr -fno-sanitize=vptr -fno-
 sanitize=vptr -fno-sanitize=vptr -std=c++11' --extra-
 cflags=-I/ffmpeg/repo/gcc11-O2/ffmpeg_deps/include --extra-
 ldflags=-L/ffmpeg/repo/gcc11-O2/ffmpeg_deps/lib
 --prefix=/ffmpeg/repo/gcc11-O2/ffmpeg_deps --pkg-config-flags=--static
 --optflags=-O2 --enable-gpl --enable-libass --enable-libfdk-aac --enable-
 libfreetype --enable-libopus --enable-libtheora --enable-libvorbis
 --enable-nonfree --disable-shared
   libavutil      57.  7.100 / 57.  7.100
   libavcodec     59. 12.100 / 59. 12.100
   libavformat    59.  6.100 / 59.  6.100
   libavdevice    59.  0.101 / 59.  0.101
   libavfilter     8. 14.100 /  8. 14.100
   libswscale      6.  1.100 /  6.  1.100
   libswresample   4.  0.100 /  4.  0.100
   libpostproc    56.  0.100 / 56.  0.100
 }}}
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/9476>
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