ffmpeg -i FILE -map_chapters "-1" -map "0:0" -map "0:1" -sn -vf subtitles=SUBS.ass -map "0:2" -c:v libx264 -b:v 1800k -maxrate 1800k -bufsize 3200k -c:a aac -strict experimental -ac 2 -b:a 128k -movflags +faststart FILE.m4v