[Openal] 5.1 Surround sound under MS Vista and openAL

[Daniel PEACOCK]

Hi Benoît,

There are a couple of things going on here ...

- Multi-speaker output is not available on all OpenAL devices.  The
'Generic Hardware' and 'native' X-Fi and Audigy devices support
multi-speaker output (and play multi-channel Buffers).  The 'Generic
Software' device is stereo only (you can play 5.1 Buffers, but they will be
downmixed to stereo)

- On Window Vista, Microsoft removed the 'Hardware Abstraction Layer' which
means that DirectSound3D can no longer be hardware accelerated by a
soundcard.  This means that the OpenAL device 'Generic Hardware' which uses
DirectSound3D Hardware Buffers no longer functions on Vista.

This means that if you don't have a soundcard with a 'native' AL Device
then you won't get multi-speaker output on Windows Vista.

Dan
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             Benoit Hamet                                                  
             <benoit.hamet at mis                                             
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             ensource.creative                                     Subject 
             .com                      [Openal] 5.1 Surround sound under   
                                       MS Vista and openAL                 
                                                                           
             04/17/2007 02:02                                              
             AM                                                            
                                                                           
                                                                           
                                                                           




Hi all,

I'm trying to test openal for internal usage with surround sound. After
playing with the configuration I finally managed to get my 5.1
configuration working (I test it with the multichannel audio sample
played by WMP given in the media directory of the OpenAL SDK Samples).
But when trying to test it with the tools given by openAL, (ie the
playMultichannelSample), then the sound is only in 2.1.

Does some of you have ideas on what is going ? I try to look into the
mail archive of openAL, digging around take a look  in the DirectSound
systems (was hopping to find how to configure it for 5.1 systems), but
no luck.

OpenAL come from Creative Labs site, The sound card is an onboard one
(so when enumerating it's recognised as a Generic Card with 256
channels), and Windows vista is the professional version.

Thanks in advance for your help.

Regards,

Benoît.
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