[BUG] Sound stutters on Windows Vista

[Dasperal]

International Doom version

Inter Doom 6.2.1 and 142f489

What Operating System are you using?

Windows Vista

What Build variant of International Doom are you using?

x86 (x32, win32)

Please describe your specific OS version

Windows Vista Ultimate SP2 x86

Relevant hardware info

AMD Ryzen 7 3700X, Nvidia GTX 1080

Have you checked that no other similar issue already exists?

• I have searched and not found similar issues.

A clear and concise description of what the bug is.

On Windows Vista x86 there are sound lags for every supported audio type (MP3, MOD, FLAC, opus, vorbis) and synth (OPL2, OPL3, GUS), except MIDI (Windows Native MIDI API).
Expected (Win 7 x64): https://www.youtube.com/watch?v=Ix6Mwx4Bkss
Actual (Win Vista x86): https://www.youtube.com/watch?v=oMDluIHAqSY

Steps to reproduce the behaviour.

1. Start Inter Doom under Windows Vista x86.
2. Select any music synth, except MIDI.
3. Experience sound lags.

Your configuration

https://gist.github.com/Dasperal/f5bdce5b870620c1137b0dba788679ba

Provide a Log

https://gist.github.com/Dasperal/c407ea7495e488ca772d6c38e782c9d5

[Dasperal]

libsdl-org/SDL_mixer#512

[Dasperal]

The stutters were caused by the wasapi audio driver. To fix them, we need to set SDL_HINT_AUDIODRIVER to directsound before audio subsystem of SDL is initialized. I think the best place for now will be in i_main.c because initialization sequence is quite complicated. Audio subsystem of SDL can already be initialized once we come to initialization of the music module.

Our audio subsystem really needs a big refactoring.

[Dasperal]

For current releases, you can create *.bat file with the following text:

Set SDL_AUDIODRIVER=directsound
inter-doom %*

and use it to run inter-doom.