[L2Ork-dev] Flatpak build - audio backend testing

[Sam Thursfield]

On Mon, Jul 20, 2020 at 11:22 PM Jonathan Wilkes <jon.w.wilkes at gmail.com> wrote:
> > > 4. With the pulse device selected and a youtube video paused, what
> > > happens if the user chooses a
> > > direct-audio-hardware-access device in the audio list and clicks "Ok?"
> >
> > Probably something like this:
> >
> >     snd_pcm_open (input): Device or resource busy
> >     snd_pcm_open (output): Device or resource busy
> >
> > Followed by a lack of sound :)
>
> That would be unfortunate.
>
> With all of Pulse's high level abstractions, is there really no way to tell
> it, "I'm ready for exclusive low-latency access now, please move everyone
> else out of my way."

There is a way to do this, which involves claiming the D-Bus name
`org.freedesktop.ReserveDevice1.<device>` when you want to take over
the audio hardware. It's documented at
http://git.0pointer.net/reserve.git/tree/reserve.txt and I can see
code in Ardour which does this.

With nothing else producing sound on the machine, direct hardware
access should work without needing to manually kill pulseaudio. Maybe
pausing a youtube video isn't enough to release the hardware though.

Sam