Implications for Wine from the Ubuntu Developer Summit -- Pulseaudio
susancragin at earthlink.net
Tue Jun 2 08:57:17 CDT 2009
>2009/6/2 Scott Ritchie <scott at 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
>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 +
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.
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