[openal] Audio quality and upsampling

[Chris Robinson]

On 07/02/2016 01:03 AM, alberto box wrote:
> Hi Chris, thank you for your answer.
>
> In your opinion the api exposed by my old creative version are the same api
> exposed by the newer openal soft? I mean is there a chance for me to update
> the libraries only, without working on the source code?

You can just replace the DLL without changing the app's source, yes. You 
can also have OpenAL Soft added to the list of OpenAL devices so you can 
change between them (if the app lets you choose).

There's a few small caveats, though; first one being that OpenAL Soft 
doesn't have the EAX extension (it's long been deprecated in favor of 
the newer EFX extension, also supported by Creative and covers the same 
functionality), so if the app uses the old EAX interface instead of EFX, 
you won't have effects.

Secondly, OpenAL Soft is a little more strict when it comes to reporting 
errors. OpenAL Soft does a better job of letting an app know that 
something didn't work, and oddly, I've heard of (very very few) apps 
that don't like being told something didn't work, even though it never 
worked.

It's unlikely your app will be bothered by this, though. OpenAL's EAX 
was only used in relatively few apps in the early 2000s, quickly being 
replaced by EFX. And as I said, extremely few apps are bothered by the 
improved error reporting (I think I've only had one confirmed case), 
plus there are some workarounds that may help.


As far as resampling goes, once you have OpenAL Soft's DLL in place, you 
should run the alsoft-config GUI utility (included in the binary 
download), then under the Resources tab change the Resampler as desired, 
and hit Apply. Then anything that uses OpenAL Soft will use that 
resampler for sounds.