[FFmpeg-trac] #3019(undetermined:new): fieldmatch + decimate causes out-of-sync audio

[FFmpeg]

#3019: fieldmatch + decimate causes out-of-sync audio
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             Reporter:  spookybathtub  |                     Type:  defect
               Status:  new            |                 Priority:  normal
            Component:  undetermined   |                  Version:  2.0.1
             Keywords:  ivtc, filters  |               Blocked By:
             Blocking:                 |  Reproduced by developer:  0
Analyzed by developer:  0              |
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 Summary of the bug:
 Using fieldmatch and decimate filters together throws the audio out of
 sync.  Source video is 29.97i with 3:2 pulldown.
 How to reproduce:
 {{{
 $ ffmpeg -ss 900 -i NCIS.ts -t 30 -vf "fieldmatch, decimate" -pix_fmt
 yuv420p -acodec copy -vcodec libx264 -preset ultrafast fm-decimate.mkv
 ffmpeg version 2.0.1 Copyright (c) 2000-2013 the FFmpeg developers
   built on Sep 25 2013 06:03:35 with Apple clang version 4.1
 (tags/Apple/clang-421.11.66) (based on LLVM 3.1svn)
   configuration: --prefix=/opt/local --enable-swscale --enable-avfilter
 --enable-avresample --enable-libmp3lame --enable-libvorbis --enable-
 libopus --enable-libtheora --enable-libschroedinger --enable-libopenjpeg
 --enable-libmodplug --enable-libvpx --enable-libspeex --enable-libass
 --enable-libbluray --enable-gnutls --enable-libfreetype --disable-
 outdev=xv --mandir=/opt/local/share/man --enable-shared --enable-pthreads
 --cc=/usr/bin/clang --arch=x86_64 --enable-yasm --enable-gpl --enable-
 postproc --enable-libx264 --enable-libxvid
   libavutil      52. 38.100 / 52. 38.100
   libavcodec     55. 18.102 / 55. 18.102
   libavformat    55. 12.100 / 55. 12.100
   libavdevice    55.  3.100 / 55.  3.100
   libavfilter     3. 79.101 /  3. 79.101
   libavresample   1.  1.  0 /  1.  1.  0
   libswscale      2.  3.100 /  2.  3.100
   libswresample   0. 17.102 /  0. 17.102
   libpostproc    52.  3.100 / 52.  3.100
 }}}
 The above produces properly detelecined video at 23.98p, but the audio is
 out of sync.  The problems still happens if I add the yadif filter in
 between.
 {{{
 ffmpeg -ss 900 -i NCIS.ts -t 30 -vf "fieldmatch" -pix_fmt yuv420p -acodec
 copy -vcodec libx264 -preset ultrafast fm.mkv
 }}}
 With this command, audio sync is fine, but video output is 29.97p.

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/3019>
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