WDM-KS not working (Windows platform)

[bbouchez]

Bug Summary

Selection of WDM-KS audio backend on Windows is not recognized (LMMS does not want to start) or blocks totally audio rendering (sequencer does not start)

Steps to reproduce

On Windows machine only !
Menu Edit -> Configuration -> Audio tab
Select PortAudio / BACKEND : Windows WDM-KS / DEVICE : any WDM device available for output
(Bug has been reproduced with 3 different interfaces : Realtek HD Audio integrated audio, M-Audio Fast Track, XMOS XC200 USB Audio interface)
Restart LMMS

Expected behavior

LMMS should start properly when WDM-KS devices are selected.
LMMS should play tracks properly when WDM-KS devices are selected

Actual behavior

In 50% of cases, LMMS does not start once WDM-KS backend is selected and asks to choose another audio interface (while the interfaces work as WDM devices in other applications). Selecting WASAPI with the same devices works perfectly.

When LMMS accepts to start with WDM-KS selected (in the other 50% of cases), CPU load raises immediately to very high level even with the default project. Loading a simple project makes the CPU reach 100%. Task manager shows "System interrupts" at 100% in that case.
Sequencer also does not start when PLAY button is clicked

Screenshot

LMMS version used

1.2.1

Logs

Click to expand

[bratpeki]

Tried this on the latest nightly, on some old Windows 10.

PortAudio in general seems to make a lot of issues. MME or WDM-KS, both cause the system audio to brick. After closing and reseting to SDL or JACK, the issue persists, and Chrome doesn't seem to be able to generate sound.

[Rossmaxx]

Can you try if #7444 fixes any of this?

[bratpeki]

I'm still having issues with compiling, as described in #7526. Could you generate a Windows build?

If it's a hassle, I can test it once I get compiling on Windows down.

[Rossmaxx]

https://lmms.io/download/pull-request/7444

Here you go. You can try this trick for any other PR. But do note that builds might expire after 90 days of inactivity (or some other period)

[sakertooth]

@bbouchez, hello, could you test #7444 to see if it fixes the issue? @bratpeki has tested it but had no luck with WSAPI and WDM-KS, so I'm holding out hope that maybe its the OS configuration (or if LMMS is built with MinGW 🤔) causing the problem.

A link to the PR build for Windows can be found here.