[pulseaudio-discuss] Accessing audio as root

[Lennart Poettering]

On Sun, 03.01.10 21:26, Ng Oon-Ee (ngoonee at gmail.com) wrote:

> On Sun, 2010-01-03 at 07:41 -0500, Bill Cox wrote:
> > Hi, Colin.  I disagree that speech-dispatcher and speechd-up are
> > broken and need to be fixed.  speechd-up is a root daemon attached to
> > the /dev/softsynth device.  I see no utility in having multiple copies
> > of it.  Speech-dispatcher opens an IP port to act as a speech server
> > over the network.  It's kind of a silly feature, but why should I
> > second-guess the speech-dispatchers developers and break it?
> 
> > IMO, what's broken is PA.  I can't in Ubuntu get two copies running on
> > the same machine without borking the sound system.  If PA can't even
> > do it, why should I mangle all the accessibility apps out there by
> > making them try to follow PA's overly complex model?  This has to be a
> > screaming violation of the KISS rule.  The sound system is a bit
> > complex.  Fine.  To use it, you need to make all your apps complex?
> > Really?
> > 
> > The complexity has to be contained.  It can't keep leaking out of PA
> > into the rest of the system, making it more and more unstable as it
> > goes.
> > 
> > Bill
> 
> IMO from what I've read so far, PA's model is "one instance per user".
> Whether or not its 'overly complex' depends on point-of-view, since this
> is the same model used by (for example) X11 and jackd. I believe that,
> in a multi-user system, user-space apps and services should be "one
> instance per user". Of course, I can see how this could be 'overly
> complex' from a developmental point of view, but its really a matter of
> the way you view your system.
> 
> On the other hand, your app (speechd-up) is by its very nature a "one
> instance per system" app, as all apps which run as root are (should
> be?). Not knowing much about how it works, I can just state my belief
> that it won't be easy to change.

I don't think it is the "very nature" of a tts daemnon to be
per-system. Not at all. It's something per session/seat by its very
nature if you ask me. If you move a session between two seats (whcih
we plan to allowa in the longer run) or if you access a session
remotely, then the tts daemon needs to output its audio on the sound
card that belongs to the keyboard/screen (i.e. seat) the user happens
to sit at, and certainly not on the sound card that is built into the
server that stands 50km away or where the session was originally
started on.

Lennart

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