[pulseaudio-discuss] Automatic selection of an audio sink depending on value of ENV variable

Lennart Poettering lennart at poettering.net
Sun Oct 25 17:25:05 PDT 2009

On Tue, 20.10.09 18:32, Michał Sawicz (michal at sawicz.net) wrote:

> Dnia 2009-10-20, wto o godzinie 17:18 +0100, Colin Guthrie pisze:
> > Did you try setting the xprops manually? Make sure that works first 
> > (although if pax11publish is looking at the wrong display, it could
> > be 
> > the pulse client libs are doing the same...) 
> Doesn't 0.0 and 0.1 mean there's only one root window - thus only one
> default sink to be set through pax11publish?

Nah. On X11 there are displays, screens and monitors.

A display consists of one or more screens. A screen consists of one or
more monitors.

A root window is something that is assigned to a screen. 

Having multiple monitors on a single screen is what people tend to
refer to as Xinerama.

PA always looks into the root window of screen 0 of the display --
under the assumption that it is actually the display we want to attach
data to, and not a screen or a monitor. pax11publish does that, the
client libs do it and the pa server too. However, as mentioned this is
fixable. In this particular case outlined in this thread it seems to
be requested to make those props per-screen and not per-display. We
can do this, Not sure it makes a lot of sense though in the general
case, and makes we wonder how long before someone wants to attach this
informaton to a monitor, not a screen or display.

And then again, running a display with multiple screens is kinda
exotic in my eyes. The more common case is to have one screen with
multiple monitors. And that's what we should optimize for.

But hey, a clean patch can be a very convincing argument. Walk the
walk, don't talk the talk!


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

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