Record Desktop
ffmpeg can be used to record the desktop.
ffmpeg -f x11grab -s wxga -r 15 -i :0.0 -qscale 5 out.avi
wxga
specifies the resolugion 1366 x 768.
ffmpeg also supports cutting the video:
ffmpeg -i out.avi -ss 4 -t 00:02:07.0 -vcodec copy cut.avi
The parameter ss
skips the first x seconds. The parameter t
specifies the duration in the format HH:MM:SS.sss
.
Converting the video from avi to mpeg:
ffmpeg -i cut.avi -vcodec libx264 -preset veryslow -crf 0 transcoded.mp4
Slow down or speed up recording:
mencoder -ovc copy -oac copy -speed .5 transcoded.mp4 -o transcoded-slow.mp4
ffmpeg -i transcoded.mp4 -vf setpts=2*PTS -an transcoded-slow.mp4
Adding subtitle:
ffmpeg -i subtitle.srt subtitle.ass
ffmpeg -i transcoded-slow.mp4 -vf "ass=subtitle.ass" out.avi