[FFmpeg-user] overlay filter corrupts timing of the video

[Martin Ždila]

Hello

When I run following command against file in
http://filebin.ca/2z88Rc4fcYbB/videos.tar then output timing is corrupted -
result is like 1 FPS.

ffmpeg -y -i a.mp4 -filter_complex "
  nullsrc=size=320x240 [bg];
  [0:v] scale=320x240 [main];
  [bg][main] overlay=shortest=1" \
-c:v libx264 -preset veryfast a.tmp.mp4

Is there a way to fix it?

PS: It is only a reuced complex usecase with no real meaning.

Thanks

ffmpeg version 3.1.4-1 Copyright (c) 2000-2016 the FFmpeg developers
  built with gcc 6.2.0 (Debian 6.2.0-6) 20161010
  configuration: --prefix=/usr --extra-version=1 --toolchain=hardened
--libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu
--enable-gpl --enable-shared --disable-libtesseract --disable-stripping
--disable-decoder=libschroedinger --enable-avresample --enable-avisynth
--enable-gnutls --enable-ladspa --enable-libass --enable-libbluray
--enable-libbs2b --enable-libcaca --enable-libcdio --enable-libebur128
--enable-libflite --enable-libfontconfig --enable-libfreetype
--enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug
--enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse
--enable-librubberband --enable-libschroedinger --enable-libshine
--enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh
--enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx
--enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid
--enable-libzmq --enable-libzvbi --enable-openal --enable-opengl
--enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-frei0r
--enable-chromaprint --enable-libopencv --enable-libx264
  libavutil      55. 28.100 / 55. 28.100
  libavcodec     57. 48.101 / 57. 48.101
  libavformat    57. 41.100 / 57. 41.100
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 47.100 /  6. 47.100
  libavresample   3.  0.  0 /  3.  0.  0
  libswscale      4.  1.100 /  4.  1.100
  libswresample   2.  1.100 /  2.  1.100
  libpostproc    54.  0.100 / 54.  0.100

Martin Ždila