Author Topic: Audio Glitches/Static [Shōjo Kakumei Utena: Itsuka Kakumeisareru Monogatari]  (Read 1580 times)

descension

  • Newbie
  • *
  • Posts: 2
    • View Profile
Under Yabause, "Shōjo Kakumei Utena: Itsuka Kakumeisareru Monogatari" has a bunch of audio glitches. The intro video skips a bit, but more importantly, once you get to the game itself, menu sounds are muted and music/voice is just static. I know it's a fairly obscure game, but it'd still be nice to get it working. (For what it's worth, SSF seems to have no trouble.)

I've tried on both the latest official release and SVN trunk, and both have the same issues. I'm happy to provide any debug info that would help (e.g. if you need an ISO of the game). I'd work on a patch, but I don't know a thing about the Saturn's audio playback. If someone has useful pointers and doesn't mind getting me started, I could at least take a look at the code, but I'm not sure how useful that'd be...

descension

  • Newbie
  • *
  • Posts: 2
    • View Profile
I looked into this a bit. I think the main problem is that Yabause doesn't support the SCSP DSP yet. I read some specs and hacked around in the code for a while, but I think the SCSP code would need some preliminary work to actually make it possible to write the DSP emulator.

The main things I bumped up against were that 1) it's pretty hard to actually get values out of the SCSP slots (at least, the struct's members don't correspond very well to the documented fields in the Saturn manuals), and 2) the scsp_update code seems like it needs adjusted to handle the DSP step. Right now, scsp_update loops over each slot and then each audio sample, but since the DSP can run for several slots, I think it should loop over each sample and then each slot. Then you'd need to pipe the samples as appropriate from the slot, into the DSP (via MIXS) and back out (via EFREG).

I have bits of a patch for this, but I don't know enough about the Saturn (or have access to enough games to test against) to really be sure I'm heading in the right direction. Hopefully some of this is at least a little helpful to someone who actually knows about things...