Run these commands:
cd /home/jaac/torrents/rtorrent/dots
for f in *.mkv; do ffmpeg -i "$f" -map 0:s:m:language:ind "${f%.*}.srt"; done
Adapted from How do you convert an entire directory with ffmpeg?
What the -map
option is doing: 0:s:m:language:ind
is input #0: subtitles:metadata:language:indonesian
. Which means it chooses all subtitle streams from the input that have Indonesian language metadata.
If you get error:
Stream map '0:s:m:language:ind' matches no streams.
To ignore this, add a trailing '?' to the map.
You can ignore it. Just a message telling you there is no subtitle stream with Indonesian language metadata in that particular input.