[pulseaudio-discuss] Device reservation improvement suggestions

[Zeno Endemann]

Hi,

I have two suggestions how the device reservation can be improved for
app developers wanting to have exclusive access to an alsa card:

1.
I knew about this scheme only by accident, so I think the
discoverability should be improved. Adding a few lines to the PA
developer documentation site ([1]) with a link to [2] would already be
good (it took me quite a while to even find [2]).
Since the most important sound server (PA and jack, right?) are using it
and thus it having a good de facto adoption I furthermore suggest adding
the spec to the freedesktop.org specifications page. Should I ask about
this on the freedesktop mailing list?

2.
The spec implies that the reservation is for a whole device (ie. alsa
card), so I believe a well-behaving client should not touch a reserved
alsa card in any way. But PA only uses the reservation for PCM streams,
not for the mixer controls of the card. My suggestion is either fixing
PA (my preference) so that it reserves the card before writing any
changes to the mixer, or at least making it clear in the spec that the
reservation is only for all PCM devices on the corresponding card.


Thanks,

Zeno Endemann

[1]
http://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/Developer/
[2] http://git.0pointer.net/reserve.git/tree/reserve.txt