Audio CD playback issue（FF/FR）

[dengsirtc]

I found it impossible to fast-forward or rewind when playing Audio CD，is there anyone like me？

[BIOS] Super CD-ROM System (Japan) (v3.0).pce
TurboGrafx16_20220326.rbf

[dshadoff]

The audio CD portion is based heavily on the use of subcodes (as is the CD-G), and isn't full-featured at this time.
Having said that, I've tested on the audio CD player, and found that my fast-forward button causes the position to go backward, and the rewind button causes the position to go backward at a higher rate.

[dshadoff]

OK, I think this is a bug in the MSF/LBA translation, making the console think that it's 150 sectors earlier than it really is:
- the fast-forward should push it 75 sectors ahead, but really puts it 75 sectors behind
- the rewind should push it 75 sectors behind, but ends up being 225 sectors behind because of the -150 offset

I'll look into this a bit more.

[dshadoff]

Pull request submitted