[Openal-devel] openal-soft

[Chris Robinson]

On Wednesday 06 February 2008 02:33:56 pm Lukasz Pawelczyk wrote:
> Chris Robinson wrote:
> >> 1. Totally no sound in one old icculus port of a windows game.
> >
> > Which game? Some extensions have been dropped (particularly those for
> > playing MP3 and Vorbis, and the callback extension), so if it relies on
> > them, there will be issues. I won't mind adding some of the extensions
> > back, but ones like the aforementioned likely won't.
>
> Avp: http://www.icculus.org/avp/
>
> Long time abandoned port, but still I find it amusing to play it
> sometimes. To run it you need some data files which can't be freely
> downloaded. If source code is not enough for you to check it let me know.

Ah..

        snprintf(buf, sizeof(buf), "'( (sampling-rate %d ))\n", AvpFrequency);

        AvpSoundDevice = alcOpenDevice(buf);

Seems its using an SI-specific initialization config (which the spec does 
allow for, but also says it's implementation dependant). Simply using NULL 
instead of buf, or an empty string for buf, should work.

> > You can try forcing the default alsa device to a hardware voice (by
> > default it uses the 'default' device, which is kinda touchy in what it
> > does). You can also try to enable full 4 or 5.1-channel mixing. Using
> > OpenAL Soft 1.2, you can create ~/.alsoftrc and add the lines:
>
> I perfectly know all of this, I wouldn't dare to report rear speakers
> not working if I was using 2 channel device :-)

My apologies.

> 'default' and 'hw' devices in my case are 2 channel (emu10k1). I tested
> it on surround40 and my own 'default' definition (build on top of
> surround51 with headphones output made of center/lfe + softvol, posted
> in attachment). On both of it and original openal there is rear speakers
> sound, on soft one, only front ones are playing.
>
> The game I'm talking about is BTRL: http://game-warden.com/bsg/

HMm.. I'm not quite sure how it handles OpenAL. If it simply streams a 
pre-mixed stereo stream, it's possible that because the SI downmixed it to 
mono it then played out over all speakers equally, or in the later SVN 
revisions it kept it as stereo and duplicated the left and right channels.. 
whereas OpenAL Soft keeps it as stereo and plays out only the front-left and 
front-right speakers.

I guess I could make stereo duplicate to quad, but I'd worry about the extra 
loudness of it way overpowering the mono sources, which are properly scaled 
so it has the same perceived volume regardless of if it's playing on all 2 
(or 4) speakers or panned to one.

> The only reason I reported it is that I wanted to fully replace SI
> implementation with soft in my system and alext.h and static versions
> were the things I was missing. Static lib is not crucial for me and even
> if it will be I can easily make one myself. Just thought that building
> one with upstream wont hurt.

Personally, I'd not want to automatically make a static lib so as not to 
encourage static-linking. However, if it really is a requested "feature", 
I'll reconsider.

I'll likely make an alext.h though.

> I'll be providing more user-kind feedback soon. For now I tested BTRL,
> AvP and UT2004. I'll test Penumbra, X2, X3 (as soon as new beta comes
> out) and probably some older Loki/LGP games I might have somewhere.

I look forward to hearing about them. :)