Re: Implications for Wine from the Ubuntu Developer Summit -- Pulseaudio

[Susan Cragin]

> 2009/6/2 Scott Ritchie <scott(a)open-vote.org>:
> > First, I talked with a Pulseaudio expert about what we can do to make
> > things work better.  He said that if we want good compatibility we will
> > need our ALSA stack to use the Pulseaudio safe subset:
> > http://0pointer.de/blog/projects/guide-to-sound-apis.html. I've filed a
> > metabug tracking this here:
> > http://bugs.winehq.org/show_bug.cgi?id=18740.  Use of this unsafe subset
> > can cause most problems with stuttering or even complete dropoff.
>
> As far as I know, this is not possible for Wine (without massive
> latency issues caused by overbuffering in Wine itself) due to the fact
> that Wine has to make DirectSound apps happy. It's also not very
> consoling from this Pulseaudio expert that they don't seem to see a
> problem with the ALSA layer on their end - "it's the apps that need to
> be fixed". Wasn't the point of Pulse that you could use libasound/OSS
> apps without modification? :)
> > I'm not completely familiar with how sound works in Wine, but in the
> > past I remember that one complaint about PulseAudio over ALSA was
> > latency.  Latency issues these days are mostly due to bad kernel
> > configurations
>
> PulseAudio will *always* have more latency than ALSA. This has nothing
> to do with kernel configurations, just that using a
> CONFIG_NO_HZ/CONFIG_HZ_1000 (or whatever it is) kernel from the -rt
> tree makes the latency issue less severe. New kernel won't fix Wine +
> Pulse problem.

Forgive me in advance for interjecting dross into a technical discussion. Would part of the problem be solved if users could be given the option of installing pulseaudio? That way, some users would be made instantly happy. 

There is a subset of users (albeit a tiny subset) that just needs one sound application running, but wants that application running with crystal-clear sound and near-zero latency. These are certain professional audio users, and those who run Dragon NaturallySpeaking through wine. Those people may be ill-served by having pulseaudio at all. 

Right now, in wine, removing pulseaudio completely doesn't seem to return alsa's functionality. Wine/alsa freezes, and I have to use OSS emulation, but OSS just does not produce as high-quality a sound. 

PS -- The rt kernel really is wonderful for speech recognition or any other use. The repository version has problems that are being worked on. In the meantime, just compile your own.