jack needs default configuration so it automatically launches

[Ralf Nieuwenhuijsen]

Problem:
IDJC uses jack. IDJC uses the 'new' behavior of jack to automatically launch itself.
However with an /etc/jackdrc file it will try to launch itself using 'jackstart' instead of 'jackd'. Jackstart however only works with 2.4.X kernels .. we need to use jackd for the 2.6.X kernels ..

Solution:
Jack-audio-connection-kit should come with default configuration file

---example configuration file----
/usr/bin/jackd -d alsa -r 44100
---end of example configuration file---

It should be called /etc/jackdrc and it should be part of the jack-audio-connection-kit package.

Will the maintainer please update the package?

[Lionel Le Folgoc (mrpouit)]

Hi,

/usr/bin/idjc contains:
-----
# Make JACK sound server start on demand
export JACK_START_SERVER="1"
-----
so jackd is automatically launched when needed, and stopped when all clients exit.

However, when running idjc from a terminal, it displays:
-----
[...]
jackstart: md5 checksum for /usr/bin/jackd does not match
[...]
-----
So it seems this issue comes from jackd

[Ralf Nieuwenhuijsen (ralf-nieuwenhuijsen)]

It seems that nowadays the jack-libraries themselves start a jack-server if needed.. however they run jackstart instead of jackd.

The man pages voor jackstart and jackd are the same and they contain this phraze:

  "The jackstart command provides JACK’s built-in support for Linux 2.4.x kernels with the realtime capabilities patch. Use jackd for Linux 2.6.x and all other systems. All parameters are the same."

In other words, with our kernels, we need it to launch jackd instead of jackstart.
On that same manual page I find:

********************************************************

"JACK is evolving a mechanism for automatically starting the server when needed. Any client started without a running JACK server will attempt to start one itself using the command line found in the first line of $HOME/.jackdrc if it exists, or /etc/jackdrc if it does not. If neither file exists, a built-in default command will be used, including the -T flag, which causes the server to shut down when all clients have exited.

As a transition, this only happens when $JACK_START_SERVER is defined in the environment of the calling process. In the future this will become normal behavior. In either case, defining $JACK_NO_START_SERVER disables this feature."

********************************************************

Long story short:
It works if you either have a .jackdrc or an /etc/jackdrc file containing the following line: "/usr/bin/jackd -d alsa -r 44100"

However, so this bug is not a bug of idjc after all, but a jack-bug which, being shipped with a 2.6 series kernel, should have a configuration file in /etc by default

So i'm setting it to confirmed for jack-utils and to rejected for idjc..