[pulseaudio-discuss] jack soundcard reservation behavior

[Fernando Lopez-Lezcano]

Hi, new on this list... (please keep cc'ing Stephane, he's not in the pa
list). 

I'm testing the jack soundcard reservation dbus code with the latest
release of jackmp (1.9.3) and I'm not sure things are working quite
right. 

When starting jackd the soundcard is correctly reserved, pulseaudio
releases it, and jackd is able to start normally and use the card. A
stream that was playing through the soundcard at that point in time
seems to be paused by the reservation code (I'm using rhythmbox to test
but the same thing seems to happen with other apps). If running
pulseaudio with -vvv I can see a message re: the successful
reservation. 

When quitting jackd, jackd prints a message to the effect that the card
was released but nothing seems to happen on the pulseaudio side (this is
being tested on Fedora 11 with the latest pulseaudio package). No
message is printed and no state changes in the application that was
playing audio before the reservation took place. In the case of
rhythmbox I need to press "play" _twice_ to get it to continue playing
from where it stopped. 

I have been using a short perl script for this purpose that wraps the
jackd binary (I can post it if needed) and calls "pacmd suspend 1" on
startup and "pacmd suspend 0" on exit. The behavior is different. When
the wrapper script starts any application that is playing on the
soundcard keeps playing, only the sound is no longer audible. When the
wrapper script exits the application that was playing seamlessly keeps
playing at the point it is in when jack stops. 

I think I like this behavior better[*]. 

-- Fernando

[*] for example it would allow for currently playing streams to be moved
to a dynamically loaded jack plugin without missing a beat (or rather,
with a very short interruption). Part of this is also implemented in my
current script.