winmm: Test opening the same device twice

Robert Reif reif at
Tue Aug 19 16:22:14 CDT 2008

Eric Pouech wrote:
> Maarten Lankhorst a écrit :
>> Behavioral test to show that wine winmm needs fixing.
>> ---
>> ------------------------------------------------------------------------
> this likely is going to fail on old boxes
> there's no requirement on MS side that a PCM renderer has to be opened twice
> so having it as a test is wrong
> some old cards with OSS as a driver forbid the card to be opened twice 
> (especially in different processes). IIRC, there was a bit of support in 
> the OSS driver (not sure about the ALSA one) to allow > 1 opening in the 
> same process (and also opening one handle for sound capture and another 
> one for sound rendering).
> but this didn't provide support for mixing the output from the two 
> different handles, which is likely what part of what you're trying to do 
> assumes (especially for dsound plus standard winmm output)
> the only way out is to have the Linux (or Unix) driver handle several 
> opening including the mixing of the two streams
> if the driver doesn't provide this flexibility, I don't see a point of 
> implementing it in Wine
> A+
It will also probably fail on all Windows versions prior to 98SE.

Real OSS (not ALSA emulation) supports multiple opens on hardware
with hardware mixing (SB Live! and Audigy using the Audigy driver).

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