Tried Pulse Audio Again--No Good For A11y

[Lennart Poettering]

On Mon, 22.09.08 20:21, Chuck Anderson (cra at WPI.EDU) wrote:

> 
> On Tue, Sep 23, 2008 at 01:57:31AM +0200, Lennart Poettering wrote:
> > PA completely ignores alsa device indexes. Instead it uses HAL UDIs
> > for identifiying devices, which is much more useful. When PA is first
> > started up and no default audio device is configured, then PA will
> > pick one. It is not defined which one it will pick, and as it appears
> > it picked the wrong one for you.
> > 
> > After login you can change the default device by right-clicking on it
> > in paucontrol. However, that setting is per-user, so it won't have any
> > effect on gdm.
> > 
> > I thought of writing a small module for PA which in the case that no
> > default device is configured will try some heuristic to find a
> > suitable default (i.e. prefer PCI over USB over Bluetooth cards). Not
> > sure this would fully fix your problem though.
> 
> This may be a crazy idea--but why don't we just make the default 
> output device "all devices"--copy the audio streams to every device 
> until the user selects a specific device as the default.  This would 
> neatly solve the issue in this thread as well as other peoples' 
> confusion of "why do I have no sound" when the sound is being directed 
> to a card without any speakers attached.

Unfortunately doing this will substantially increase CPU load (because
we need to resample the streams for each of the devcies with a
slightly different sample rate and people are already complaining if
we do this for just a single stream...) and also practically disable
glitch-free audio. I.e. all the power savings are gone. Not a good
choice for a default.

There has been some work on adding SSE support to the
resampler. That's a step in the right direction. Maybe we can do what
you suggest some time in he future, but right now people would
probably just cry and call PA a teribble CPU hogger once more ;-)

Lennart

-- 
Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net         ICQ# 11060553
http://0pointer.net/lennart/           GnuPG 0x1A015CC4