Subsonic

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Subsonic is among other things a subtitle format.

Need more info.

[edit] Subtitle format

Sample:

1 97.89 \ ~:\You should come to the Drama Club, too.
1 100.52
1 100.52 \ ~:\Yeah. The Drama Club is worried that you haven't been coming.
1 103.77
1 104.13 \ ~:\I see. Sorry, I'll drop by next time.
1 107.00

Lines are only marked with start timing, and probably run until next line, so no overlapping timings.

First number might be layer or such.

Nothing else known.