[Openal] Second Life and 1.9.563

[Chris Robinson]

On Tuesday 06 October 2009 10:32:17 am Tom Porter wrote:
> I believe the configuration I am using for SL allows everything to use
> OpenAL.  The only real issue is the different between the version
> releases of OpenAL Soft.  1.8.xxx works just fine for me and I can
> continue to use it.

I ask because, if the media/music stream is played out externally (eg. through 
gstreamer's output sinks), then it might indicate a problem with OpenAL Soft's 
PulseAudio backend. But if they play out the same OpenAL device, then 
PulseAudio is properly playing OpenAL Soft's mix and the problem is elsewhere.

If it's the latter case, then I'm stumped. Second Life (v1.23.4.123908) is 
properly playing audio for me using the latest GIT of OpenAL Soft (using ALSA 
output), and there isn't any change from 1.9 that would only affect *some* 
sounds. Only thing to note is that on initial startup (before log in), I don't 
get UI sounds right away. But after playing around in the preferences for a 
little bit, or logging in, then I seem to get them.

> Something changed in the 1.9.xxx release such
> that it only partially works for me now.  I am not actually allowing
> OpenAL to use the ALSA plugin for PulseAudio, but rather have OpenAL
> configured to use the PulseAudio back end, directly.

If it's a problem with 1.9's PulseAudio backend, using Pulse's ALSA plugin may 
get around the issue. Although Pulse's ALSA plugin does have a bunch of 
issues, any differences or lack of differences between the two outputs may 
help me narrow down the issue.

> If
> I get the time, I may get the source from various places between the
> releases and see if I can determine which changes caused this behavior.

If you're familiar with GIT, it helps automate regression testing, and keeps 
the number of rebuilds needed very low. Essentially, with GIT installed you'd 
download the latest sources:
$ git clone git://repo.or.cz/openal-soft.git openal-soft
That will copy the repository into the openal-soft sub-directory.

Then start a bisect and tell GIT the last known good commit (1.8's release) 
and the first known bad commit (1.9's release):
$ git bisect start
$ git bisect good openal-soft-1.8.466
$ git bisect bad openal-soft-1.9.563

That will place the current head between the two releases. You would then 
build and install the lib, try it with Second Life, then if it works, run
$ git bisect good
or if it doesn't work, run
$ git bisect bad
or if a given commit doesn't build at all (or has another problem preventing 
you from properly testing), run
$ git bisect skip

Keep testing and doing good/bad/skip until it tells you what the first bad 
commit is. You should only need to do, at most, 10 tests given the less than 
100 commits between the two releases (probably closer to 6 or 7).

When you get the first bad commit and are done bisecting, you can run
$ git bisect reset
to reset the tree back to its original head.