I'm trying to extract subtitles from MP4 and MKV movies. I'm using mp4box (on OS X) but cannot figure out how it works.
MP4 and 3GP files
The free and cross-platform MP4Box only works with MP4 or 3GP containers. You can install it from the homepage. First, you want look at the different tracks and see which ID belongs to the subtitle track.
Look at the ID next to the subtitle track. Then, based on the track ID
Or, to export to the commonly used SRT format:
In order to extract subtitles from Matroska (MKV) files, you need the free and open source
Then, inspect the file:
This will list the tracks, for example like this:
Based on the ID of the track, call the following command, where
So, in our case, that would have been: