Alternatively you can edit the file in one operation if the desync can be fixed by adjusting the delay. *ffmpeg -i original.avi -itsoffset 0.2 -i original.avi -map 0:0 -map 1:1 -acodec copy -vcodec copy **synced.avi* http://alien.slackbook.org/blog/fixing-audio-sync-with-ffmpeg/