Lennart Poettering, creator of open source sound server PulseAudio, was recently interviewed at this year's Linux Plumbers Conference. In this Q&A he details the latest PulseAudio developments and addresses some of PA's critics. Thanks to PulseAudio, the Linux audio experience is becoming more context-aware. For example, if a video is running in one application the system should now automatically reduce the volume of everything else and increase it when the video is finished.
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Member since:2009-02-19
Member since:2006-02-25
As i said in other posts, the problem is not userspace or kernel mixing of multiple applications. The problem is mixing low latency audio with regular latency apps audio, something that Windows and OSX are able to do with CoreAudio and ASIO, that even Linux with PulseAudio can't. For that you need to be able to mix both a low latency and regular latency streams in kernel, possibly doing some resampling, otherwise a lot of CPU is wasted. Windows and OSX still do this in kernel.
Member since:2009-04-22
No, what you need is a realtime kernel. Good news: The full set of -rt patches are about to be merged into Linus' mainline kernel.
With PulseAudio you can change output device on the fly while the application is playing sound. Start JACK and PulseAudio can be automatically reconfigured to use JACK as it's output device. When JACK is stopped it can go back to output to the soundcard directly again.
This way you can have the best of both worlds. Super low latency in your pro audio apps (talking to JACK directly) and all the features of PulseAudio for everything else.
Member since:2005-07-06
Alas, what has happened is that what PulseAudio has sought to fix has been rather inadequate and what it has broken that has worked with plain ALSA, OSS and even dmix has outweighed anything it 'may' solve.
It's utterly laughable that some people think 'that' is the way to fix an already flimsy audio stack that has at least started to work over the years.
That doesn't mean that it is right for everyone else. Alas, PulseAudio is not the right solution for userspace sound handling regardless. However, there is still a sizeable proportion of processing done in the Windows kernel, and it certainly is in OS X. Don't be fooled.
PulseAudio is there not because it is a better solution but because it is intended to be a massive bandaid for apparent problems lower down.
Dream on. Let's just pretend the bug reports and compatibility issues don't exist. That's why people won't use Linux desktops. I can't believe people still use that stupid 'Just Works' bullshit.
Edited 2009-10-08 22:30 UTC
Member since:2005-07-08
That doesn't mean that it is right for everyone else.
And that doesn't mean it is not the right solution for linux either. In fact, linux developers seem to like putting that kind of things in userspace. Personally I trust more audio developers and distro packagers than a bunch of users who happen to hate ALSA and Pulseaudio.
Dream on. Let's just pretend the bug reports and compatibility issues don't exist.
Let's also pretend that all the happy Fedora/Ubuntu/etc users of Pulseaudio that have no problems with audio in their system don't exist. Let's suppose that all the distro guys are stupid and are choosing Pulseaudio because they don't know what they're doing. Let's also suppose that users won't miss all the features that Pulseaudio has and they would lose if it was removed. Let's also pretend that the bugs reported are unfixable, and let's just throw random FUD and say that those problems arise from the way Pulseaudio is designed without explaining why 
Edited 2009-10-08 22:57 UTC
Member since:
2005-07-08
It's fun to see people blaming Pulseaudio for breaking things, but they won't mention the problems that the linux audio stack had and Pulseaudio has fixed. It also seems it's getting trendy to say that Pulseaudio sucks because the linux audio stack is not perfect.
And to try to look smart, people will suggest ideas like going back to OSS and kernel-mode mixing, just like the BSDs and Opensolaris, because it's the Unix Way (tm). Yeah, Windows and OS X have a much better audio experience than Linux, and Windows has switched from kernel-mode audio mixing to userspace audio mixing in Vista, but what they know? We should follow the lead of BSDs and Solaris and use OSS. Because, as everybody knows, those two are the desktop OSes most used in the world, specially by audio hardcore users. So indeed, Linux should try to follow their lead, since their audio experience is much better than what Linux, OS X and Windows have.
The thing is, myself I'm happy with Pulseaudio. And from what I've seen, most of people is also happy with Pulseaudio, because It Just Works. They don't even know it exists. For a long time it was experimental and young, but it's getting more and more mature, and it will mature even more, it will have even less problems, it will solve even more issues, and people will love it even more. The Pulseaudio haters can't change that, and that hurts them, but they won't stop saying everywhere that Pulseaudio sucks based in their experiences from years ago.
Edited 2009-10-08 21:04 UTC