[pulseaudio-discuss] Accessing audio as root

[Bill Cox]

On Mon, Jan 4, 2010 at 1:35 PM, Lennart Poettering
<lennart at poettering.net> wrote:
> I dont see why the speech tools should be handled in any way different
> from the other acessibility tools we ship: in that they are part of
> the session. While I am no accessibility expert I am kinda sure that
> on Fedora all accessibility stuff is run inside the user session and
> the gdm pseudo-session so that the fully a11y features are available
> both before and after the login.

For reading consoles, we use speakup, which is a kernel module.  With
the speakup_soft kernel module, speakup makes the text to be spoken
available through /dev/softsynth.  There are two different popular
packages for speaking the text read from from /dev/softsynth.  The
most popular is the least flexible, but blind users like that it
almost always works: espeakup.  It runs as root, reads from
/dev/softsynth, and calls espeak to say the text.  More powerful, but
less popular is speechd-up, whierch reads from /dev/softsynth and
forwards the text to a system-wide speech-dispatcher daemon.
Speech-dispatcher enables the user to use many different voices for
speech synthesis, not just espeak.  We've got a new speech-dispatcher
pulseaudio driver which works very well, but the system-wide
speech-dispatcher daemon is causing problems.  I can get it to use the
gdm copy of pulseaudio, but since this copy of speech-dispatcher hangs
around forever, and because I always need to be able to get speech
from the consoles, it causes gdm's PA instance to hang around, makeing
the audio card unavailable to user sessions.

Colin and Luke have suggested using CK to deal with this, by killing
off speech-dispatcher and speechd-up when the user logs in through
gdm, and restarting it when they log out.  However, I am not convinced
we should be killing off the speech-dispatcher process for the
consoles, ever.  I might be persuaded, but I am very concerned that
the audio from the consoles remain reliable.  The blind use this, for
example, to fix X11 problems we all run into sometimes.

Bill