Tried Pulse Audio Again--No Good For A11y

Chuck Anderson cra at WPI.EDU
Tue Sep 23 00:21:47 UTC 2008


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.

There should be a way to override this system-wide default as well.  

Alternatively, perhaps hal-based quirks can specify the 
system-specific default sound output device.  e.g. for laptops or 
desktop models the built-in soundcard would be a sane default.  If 
there is no hal quirk for the current system, you could fall back to 
"all output devices" or the heuristics you describe above.

Basically:

1. system factory default: output to all sound cards simultaneously
2. system custom default: either hal-quirk based, heuristic-based, or 
set by sysadmin.
3. per user setting: as we have now, per user default output device 
setting.




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