snes9xgit/snes9x

Emulation runs twice as fast when interlacing is turned on

DonutSMWC opened this issue · 2 comments

DonutSMWC commented

In v1.62.3 if interlacing is turned on (LSB of $2133 is set) emulation (includes music too) runs twice as fast. Setting the emulation speed to 50% makes the game run at normal speed.

bearoso commented

That's a consequence of two things:

  1. You have rate-limited Snes9x by using vsync at ~60Hz, not using sound sync or timer synchronization.
  2. The Windows port doesn't issue a callback for every interlaced pair, only for the full composite, which means the video code isn't called. This means only sound sync will work properly.

Should be fixed in c7b77d4.

DonutSMWC commented

Interesting. Turning on sound sync did indeed fix it. Thank you!