[Openal] Use of ALC_FREQUENCY property

[Jason Daly]

Jim B. wrote:
> The existing program allows menu selection of sound quality by setting the
> maximum sampling rate. As near as I can tell, this is not useful in OpenAL. Is
> it true that the ALC_FREQUENCY property is not settable in current OpenAL
> implementations? 

I thought that it was, but it's set at context creation time, so you 
have to destroy and re-create the context whenever you adjust it.

If that doesn't work, you might try closing the device and re-opening it 
as well.

I admit I haven't tested this in a long time, so I'm just telling you 
what "should" happen :-)


> Also, in the current versions, is it possible for
> ALC_FREQUENCY to be anything other than 44100 KHz? It looks like OpenAL will
> resample any file that is not at ALC_FREQUENCY when the Buffer is loaded. So,
> there is no point in resampling before loading the Buffer -- correct?

Not unless you have your own sample rate conversion code that sounds 
better than what the OpenAL implementation gives you.


>  Also. I
> am trying to decide if it would be worthwhile to check for ALC_FREQUENCY at
> 22050 KHz (or less) and low pass filter our 44100 KHz sound files.
>   

I don't know whether you'll gain anything from that or not.

--"J"