Prune’s Blog

I’m really supprised today to see how applications uses Jack (the Linux - and other now - audio patch).

The Jack plus name is made of two parts : the application name and the “channel” name. The application name must be unique globaly, and the channel must be unique in each application.
While some seems to be configurable in both parts, some are not :

Darkice, by defaults, create a “darkice-PID:left” and  “darkice-PID:right”, where PID is the real process ID of Darkice. This ensure 2 darkice will not have the same name. The drowback is that it is very hard to find which darkice is which, moreover if you want to script that.
I made a patch for darkice so you can freely change that.

With Ecasound, a command line sound mixer and processing you can only change the channel name. If you start more Ecasound, you will have another process ecasound_2, then ecasound_3… which is not really better than the way Darkice is doing it natively.
Another issue is when you kill one Ecasound, they all die ! This is a huge issue I will have to work on quickly, but I’m pretty sure this is due to a jack naming issue.

Then what should the convention be ?

As the important part is the application name, not the channel name, it seems that this part should be configurable.  Then the channel name could be, by default, either a direction and a number, or a direction and a name :

- ecasound-test1:in_1
-  ecasound-test1:in_2
- ecasound-test1:out_1
- ecasound-test1:ou_2

- ecasound-filter2:in_left
- ecasound-filter2:in_right

Devs, please, think of it !