[gentoo-user] Re: Phonon + PulseAudio Problem

[Nikos Chantziaras]

On 05/20/2010 10:25 PM, Canek Peláez Valdés wrote:
> On Thu, May 20, 2010 at 2:04 PM, Nikos Chantziaras<realnc@×××××.de>  wrote:
> [snip]
>> What doesn't work is PulseAudio, actually.  Too many problems with it. Pulse
>> is simply broken by design; it's too far from the kernel to be any good.
>
> If I may use (most of) your words: "Well, it works here.  It's been
> rock-solid through months." And with various use-cases, if I may add.
>
> Can you elaborate why the audio architecture has to be close to the
> kernel? The part that talks to the hardware obviously has to, but why
> the part that handles the features, the mixes, the virtual devices?

Because as soon as you disable ALSA dmix and/or Pulse, suddenly you get 
acceptable sound latency.

With OSS4, which has in-kernel mixing, it doesn't matter if you enable 
the mixer or disable it; sound always has acceptable latency.

Thus, I can only conclude that mixing has to happen in-kernel.  But I 
base this only on the ALSA/Pulse vs OSS4 comparison.  It could also be 
that the user-space implementation of ALSA just sucks.  But that's hard 
to believe, since if that were the case they would have fixed it several 
years ago already.


> I'm under the impression (correct me if I'm wrong) that it was one of
> the major reasons to leave OSS4 outside the upstream kernel; too many
> stuff in there that belongs in user space. It sounds reasonable to me.

It sounds reasonable from a designer's point of view.  But a system is 
useless if it's only designed good but doesn't actually work in a 
satisfactory manner.


> Specially when PulseAudio just works, for me and many more.

Sorry, that just pretentious of you here.  PulseAudio is the most flamed 
at, hated, sound-related software around.  And this is because it does 
*not* work for many, many users, and the first thing they try to do is 
find out how to disable the thing.


>> ALSA can't switch to Bluetooth either.  You could use PulseAudio with OSS4
>> instead of with ALSA though, but this is not officially supported.
>
> Indeed it's not supported, because it's (using your words again)
> "broken by design" by trying to do too many things inside the kernel
> that belong in user space. That's my understanding at least; please
> correct me if you believe I'm mistaken.

You're mistaken in that a mixer should be in the same boat as network 
streaming, bluetooth, etc, etc.  I believe the *mixer* should be 
in-kernel.  Everything else doesn't need to be.  PulseAudio's extreme 
latency problems (which even upstream admits can't be fixed easily) stem 
from that.