On 04.08.2009, at 16:23, David Corking wrote:

> Bert wrote:
>
>> If anyone wants to fix this for real, the ticket is
>>
>> http://bugs.squeak.org/view.php?id=7328
>
> (1)
>
> Thanks for the link.  Will the workaround be in the next Squeakland
> version of /usr/bin/etoys ?

Only if someone can think of a way to reliably detect the problem.

> (2)
>
> What benefits are there from maintaining ALSA or PulseAudio support in
> the VM?   As far as I know they are specific to Linux(*), while OSS
> (Open Sound System) works on most Unix except Mac OS X.

OSS is obsolete. It's not supported out-of-the-box on most modern  
Linux distros anymore. If at all, it is provided by an emulation layer  
like alsa-oss which adds considerable delay. We would get Squeak  
talking to OSS talking to emulated ALSA talking to PulseAudio talking  
to real ALSA. No wonder there is delay in that.

Here is an overview of the various Linux sound APIs:

http://0pointer.de/blog/projects/guide-to-sound-apis.html

> Which sound interface does the OLPC XO (and Sugar) need?


Etoys sound works fine on the XO, which uses an older Fedora with  
straight ALSA. But Sugar runs on all distros, and the newer ones  
reroute ALSA calls to PulseAudio. This is what appears to break Squeak  
sound, because it works fine on "real ALSA" but breaks on "emulated  
ALSA".

The Right Way To Fix It would appear to be rewriting our ALSA plugin  
to use the "safe subset" of ALSA which is properly understood by  
PulseAudio.

- Bert -