I have a lot of MKV video files that have dual language audio tracks.
My goal is to extract both audio tracks and have them be synchronized. Some of the files have one language track start at a different time with the start_time setting.
Example:
English track, start_time: 0
Japanese track, start_time: 3.1
What I want to do is keeping this offset after extracting audio, right now the English audio file would always be 3.1s behind the Japanese audio.
The commands I currently use:
ffmpeg -y -i "movie.mkv" -map 0:a:0 -ac 2 -ar 44100 "jap.aac"
ffmpeg -y -i "movie.mkv" -map 0:a:1 -ac 2 -ar 44100 "eng.aac"
Since the Japanese track has a start_time of 3.1s, I’d like the jap.aac file to begin with 3.1s of silence, so that the audio files match up.
How can I achieve this?
