[pulseaudio-discuss] Accessing audio as root

[Bill Cox]

On Wed, Dec 23, 2009 at 9:13 AM, Colin Guthrie <gmane at colin.guthr.ie> wrote:
 'Twas brillig, and Halim Sahin at 23/12/09 13:24 did gyre and gimble:
>> The Problem can be summarized in one sentence:
>> Pulseaudio currently breaks multiuser systems and is only useful for
>> one-user-desktop.
>
> Actually no, the exact opposite. PA works very well for multi user
> desktops.

Hi, Col.  Let me say I'm beginning to be a fan of your posts, as I
read more of them.  This is probably an Ubuntu issue, but in Karmic
and Lucid, Switch User does not change the permissions for the sound
card, and the new user will be mute.  It's a fairly minor bug... the
work-around is logout and log back in.

IMO, Halim's more important comment was that PulseAudio breaks
accessibility.  Speakup is either the #1 or #2 most popular Linux
accessibility program for the blind and visually impaired.  It starts
at boot, as it should, so a blind person can hear what's going on.

Gdm kills PulseAudio when a user logs in.  Speakup runs forever, and
it' PulseAudio process hangs around forever, locking up the sound
card, so the user can't get any sound in Gnome.

I'm not a bad C coder.  I can patch this and make it work.  But I
don't want to go writing a random work-around blindly!  I need advice
as what the right solution is.  Here's one thought, but I haven't
examined the code effected.  What if we allow certain users parallel
access to particular sound card?  Speakup launches speechd-up which
launches speech-dispatcher during boot, as user 'speech-dispatcher'.
If speech-dispatcher ran as gdm instead, and we allowed gdm to always
access the sound card?  That way, gdm would reuse speech-dispatcher's
copy of pulseaudio rather than making a new one, and we'd no longer
have to worry about killing gdm's copy of pulseaudio when a user logs
in, or restarting it when he logs out.

Is that the best way to patch this system?

Thanks,
Bill