[openal] Querying speaker configuration

Chris Robinson chris.kcat at gmail.com
Sat Oct 4 10:52:38 EDT 2014

On 10/04/2014 06:54 AM, Peter Mulholland wrote:
> Surely if you were using a single source to play a 5.1 or 7.1 premixed
> source, it is up to OpenAL to convert it if appropriate for the output
> format?

Yup. You could just mix to a 7.1 stream, and OpenAL Soft will 
automatically down-mix it to stereo, quad, 5.1, or whatever else for 
output. With HRTF enabled, you'd even get virtual 7.1 playback, with the 
front and back channels sounding like they're coming from in front and 
in back. No need to know the output format.

Of course, ideally you'd want to provide the individual mono sources and 
pan them around, letting OpenAL Soft do the mixing since that will take 
full advantage of HRTF or vertically-aligned speakers when available.

>> It would quickly get to a point where all OpenAL could do is lie about
>> what it is and remix the
>> input to fit the output, putting you back where you are now.
> Isn't it doing that already?

Pretty much, so you basically end up back where you started -- not 
knowing the actual format, and having OpenAL just remix what you give it 
to fit the output. At most, you could get a "best fit" format, but I 
don't think there's much downsides to just using 7.1 when available and 
letting OpenAL handle fitting it.

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