[alsa-devel] [pulseaudio-discuss] idea: a reserve alsa plugin

[David Henningsson]

On 05/02/2013 02:37 PM, Arun Raghavan wrote:
> On Thu, 2013-05-02 at 12:55 +0200, David Henningsson wrote:
>> Just had an idea which I'll write down here before I forget it
>> again...and I'm not saying I'll implement this anytime soon either, but
>> here goes:
>>
>> There is a device reserve protocol between PulseAudio and JACK2 - when
>> JACK needs the sound card, it'll send a dbus message to PulseAudio and
>> grab a name in D-Bus.
>>
>> However, there are plenty of applications who like to access ALSA
>> directly, without going through JACK2 or PulseAudio. By making a
>> "reserve" plugin, we could have this functionality for those apps too.
>>
>> In practice, if the app usually opens "plughw:0" or "hw:0", it could
>> instead open "reserve:plughw:0" or "reserve:hw:0" to also reserve the
>> device from PulseAudio usage while the device is open. Meanwhile,
>> PulseAudio is free to use other audio devices (which is not the case
>> when using e g pasuspender).
>>
>> How does that sound?
>
> Might be neat to do have desktops set up to do this whenever an ALSA
> device is opened (that is do it unconditionally when hw:X or plughw:X is
> opened).

Including when PA opens it? :P

I would prefer to do it explicitly, due to the possible overhead of 
talking to D-Bus.

One could possibly imagine it being done automatically with plughw, but 
definitely not with hw only because that's meant to be as low as you can 
possibly get.


-- 
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic