I am trying to extract a video clip from an mkv file, but its not accurate. I played my mkv file and noted the point e.g. starting 00:06:20 till 10 seconds. Now I executed a command like this
ffmpeg -ss 00:06:20 -i video-with-subs.mkv -t 00:00:10 -vcodec copy -acodec copy part1.mkv
The generated clip was somewhat from 00:06:12 till 10 seconds.