SCI: KQ6: Distorted music when using NukedOPL

[Papierwaite]

Select Adlib as the audio device and NukedOPL as the OPL emulator.

The quickest way to reproduce this bug: start a new game, exit the beach and then go to the left to reach the village. Enter the pawn shop (first door on the right) and stay there for a minute. Notice that some sections of the music sound garbled.

This does not happen with the other OPL emulators, and I couldn't reproduce it in DOSBox Staging (which uses NukedOPL as well).

It should also be noted that this distortion is less obvious when Alexander is on the street outside the pawn shop, even though the music which plays there is the same. My guess is this is somehow related to the way the game lowers the volume of the music when you enter the shop.

Tested on Windows 10.

[antoniou79]

Which version of ScummVM are you testing with?
Did you also test with a daily development build (2.9.0git)?

[eriktorbjorn]

My setup for testing isn't the best at the moment (and it's not my area of expertise anyway), but I think I hear a lot of popping when the volume is lowered.

Annoyingly, I don't hear this when I force it to play just single channels, so something about the way they're added together perhaps? But I don't see any clipping going on, and anyway shouldn't that be less likely to happen at lower volumes?

[Papierwaite]

About the ScummVM version, sorry, I forgot to mention that this is something I've been noticing for years, in every new release. So, to be honest, I didn't check the very latest daily build, only the latest stable version (2.8.1). I'll try it when I have a moment, but with this being such a long-standing and unreported issue, I'd be very surprised if there's any difference.

[eriktorbjorn]

There have been a couple of updates to NukedOPL upstream since the last time we synced ScummVM to it. Unfortunately, they don't seem to do anything about this bug, but I guess we should apply them anyway at some point.