Audio Volume Adjustments in psx core menu for music vs sound effects

[Zarkov]

Hi I'd like to recommend an additional setting for the psx core.

I wish I could adjust the music volume vs the sound effects volume separately. I could be missing something tho. The stereo mix setting seems to affect how much separation in the left and right channels there is but not volume.

There are games like Castlevainia SotN where the music is too low vs the sound effects. I've considered finding a way to separate out the music files on my pc and editing them, boosting their volume, then rebuilding the bin/cue or chd after wards. But that would only fix one game vs the menu option would allow for a easy way to choose the mix for any game.

Since I assume the music playing in most games are just cd audio, there must be an easy way to add in a volume adjustment that is separate from the sound effects.

Absolutely amazing work to the devs who make this all possible btw. I'm constantly amazed by what Mister can do. Thanks for everyone's efforts to preserve retro gaming.

[FPGAzumSpass]

This is not as easy as it sounds. Several things to consider:

- we cannot boost the volume, only lower it, otherwise there will be overflows
- having a useful setting will need at least 4 settings for each SPU or CD audio (0%,25%,50%,100%)
- games that read back the audio buffer (e.g. Crash Team Racing for lip sync) will not work properly anymore or even hang if you reduce the volume
- there are many games that use SPU for background music

That being said, i like the idea overall.
Need to think about if with the downsides it's still worth it.