I would like to to play the first frame of an input video for 260 frames and then play frames 310–930 of the input video:
$ ffmpeg -i video.mp4 -i video.mp4 -filter_complex '
[0:v]loop=loop=259:size=1:start=0[first-frame];
[1:v]trim=start_frame=310:end_frame=930,setpts=PTS-STARTPTS[rest];
[first-frame][rest]concat=n=2:v=1:a=0[output]
' -map [output] -c:v libx264 -crf 18 -y output.mp4
The above command produces the first frame of the input video for 260 frames as expected, but then continues with frames 0-620 of the input video followed by frames 310–930 of the input video.
When I drop the [first-frame]
part, frames 310–930 of the input video are correctly produced:
$ ffmpeg -i video.mp4 -i video.mp4 -filter_complex '
[1:v]trim=start_frame=310:end_frame=930,setpts=PTS-STARTPTS[rest];
[rest]concat=n=1:v=1:a=0[output]
' -map [output] -c:v libx264 -crf 18 -y output.mp4
This is perhaps a timestamp problem, since the documentation for the concat
filter clarifies that “for this filter to work correctly, all segments must start at timestamp 0.”
I am using the following version of ffmpeg:
$ ffmpeg -version
ffmpeg version 3.2.12-1~deb9u1 Copyright (c) 2000-2018 the FFmpeg developers
built with gcc 6.3.0 (Debian 6.3.0-18+deb9u1) 20170516
configuration: --prefix=/usr --extra-version='1~deb9u1' --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --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-libmp3lame --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --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-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
libavutil 55. 34.101 / 55. 34.101
libavcodec 57. 64.101 / 57. 64.101
libavformat 57. 56.101 / 57. 56.101
libavdevice 57. 1.100 / 57. 1.100
libavfilter 6. 65.100 / 6. 65.100
libavresample 3. 1. 0 / 3. 1. 0
libswscale 4. 2.100 / 4. 2.100
libswresample 2. 3.100 / 2. 3.100
libpostproc 54. 1.100 / 54. 1.100