[ubuntu-studio-users] Autostart jackd question

[Ralf Mardorf]

>[rocketmouse at archlinux ~]$ cat $HOME/.jackdrc 
>/usr/bin/jackd -dalsa -dhw:0 -r48000 -p256 -n2
>[rocketmouse at archlinux ~]$ $(cat $HOME/.jackdrc)

You're likely using jackdbus in combination with pulseaudio.

Regarding a short web research the above jackd line,

jackd -dalsa -dhw:0 -r48000 -p256 -n2

for jackdbus, would be a script:

#!/bin/dash
jack_control start
jack_control eps realtime true
jack_control ds alsa
jack_control dps device hw:0
jack_control dps rate 48000
jack_control dps nperiods 2
jack_control dps period 256
exit

It becomes a complex script, if you want to read the last settings used
with QjackCtl and stored as $HOME/.jackdrc and then add those values to
the jack_control command. Perhaps QjackCtl could generate a similar
file with jack_control commands, or you simply edit the script, if you
want to change the settings.

I don't know how pulseaudio and the sink thingy interact. They
seemingly correspondent by dbus.

Open an editor and copy and paste the text from  #!/bin/dash  to  exit 
to the editor, save it, e.g. name it  auto-jack.sh  , after that make it
executable with chmod:

[rocketmouse at archlinux tmp]$ ls -l auto-jack.sh 
-rw-r--r-- 1 rocketmouse rocketmouse 201 Jul  9 22:42 auto-jack.sh
[rocketmouse at archlinux tmp]$ chmod a+x auto-jack.sh 
[rocketmouse at archlinux tmp]$ ls -l auto-jack.sh 
-rwxr-xr-x 1 rocketmouse rocketmouse 201 Jul  9 22:42 auto-jack.sh

Start it by running

/path/auto-jack.sh

but don't chose /tmp as the directory, I'm using the temporary
directory only, because I never ever will use jackdbus myself.

[rocketmouse at archlinux tmp]$ /tmp/auto-jack.sh 
--- start
--- engine param set "realtime" -> "true"
--- driver select "alsa"
--- driver param set "device" -> "hw:0"
--- driver param set "rate" -> "48000"
--- driver param set "nperiods" -> "2"
--- driver param set "period" -> "256"

1. I don't have pulseaudio installed, so I can't test, if it
automatically comes with pulseaudio via dbus.

2. The first time I tested the scrip, not all IOs of my audio card
were available. Then I killed jackdbus, launched jackd, terminated
jackd and launched jackdbus by the script again, after that all
IOs were available.

IOW I can't help, because I'm a plain ALSA and jackd user. The
pulseaudio crowed needs to chime in.

Regards,
Ralf