[Openal] Software Renderer and Varying Capacities

[Daniel PEACOCK]

Hi,

There is no mixing and matching of hardware and software within an OpenAL
device, and what you are seeing is expected.

Some background .... the "Generic Software" device is a software mixer that
has a limit of 256 Sources, the "Generic Hardware" device uses *hardware*
DS3D Buffers and is limited to the amount of hardware voices supported by
the soundcard (capped at 64).    The "Generic Hardware" device is only
available if at least 16 hardware voices are found.   As you pointed out,
on Windows Vista DS3D is no longer hardware accelerated so the "Generic
Hardware" device fails the check for 16 hardware voices.

So, assuming you don't have a native OpenAL device ...

If you open the default device on Win XP you will get the "Generic
Hardware" (assuming the soundcard has 16+ hardware voices).  If you run
another application that opens the default device - it will try "Generic
Hardware" but that will fail because it won't find available voices and
fall through to the "Generic Software" device.

If you open the default device on Win Vista you will always get the
"Generic Software" device.

Dan
Creative Labs, Inc.

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             "Daniel Cruver"                                               
             <ddcruver at gmail.c                                             
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                                       [Openal] Software Renderer and      
                                       Varying Capacities                  
             08/13/2007 09:05                                              
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When working with a machine that does not have native support for OpenAL
i.e. uses the software renderer provided by Creative I have found weird
inconsistencies.

When developing on a vista machine it always had 256 mono sources minus how
many stereo sources I specifically specified in alcCreateContext function.
It correctly worked if I told it to reserve 10 sources for stereo on the
vista machine.  But then I transferred it to a XP machine and found it had
less sources to work with, only 32.  As you are aware their is no
DirectSound Hardware support on Vista so the 256 mono sources would always
be software mixed.  But the software renderer on XP has less default
sources to work with, could this because their is partial hardware support
via DirectSound.  It leads me to think this because:

1.) Other media programs when open when running application seem to take
away from the 32 available sources I can run.
2.) When running more then one occurrences of my application I notice that
any additional application that are run while the first one is running have
the 256 sources.  This really makes me think that the first occurrence has
"more" hardware supported processing while the additional occurrences will
default to 256 sources like the Vista machine does.
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