mplayer -novideo -ao pcm:file="${tmpdir}/audio.wav" -vo null "$infile"
sox "${tmpdir}/audio.wav" "${tmpdir}/audio-fixed.wav" speed "${SLOWDOWN}" gain -n
lame --preset standard "${tmpdir}/audio-fixed.wav" "${tmpdir}/audio.mp3"
- mkvmerge -o "${outfile}" --default-duration "1:${FORCEFPS}fps" --no-audio "$infile" "${tmpdir}/audio.mp3"
+ trackid="$(mkvmerge -i "$infile" | grep video | sed 's/^Track ID \(.\):.*$/\1/')"
+ mkvmerge -o "${outfile}" --default-duration "${trackid}:${FORCEFPS}fps" --no-audio "$infile" "${tmpdir}/audio.mp3"
rm -rf "$tmpdir"
done