New feature request - multiple sound cards with QJackCtl

Hello Rui

If you would like to make yourself even more popular with Linux audio users then a solution for this feature in QJackCtl would be your ticket...

On the right hand side of the set-up dialog the user can select which sound-card (hw:0, hw:0,0, hw1: etc..). Only one sound card can be selected - that is a limitation of jack 1 (I guess jack2 is the same). To use 2 or more sound-cards simultaneously it is necessary to create a virtual sound-card (in super-user mode) by modifying many configuration files in the /etc directory. This is rarely successful when attempted by the normal user.

The code in ALSA for joining inputs and outputs from multiple sound cards was written by Takashi Iwai and as far as I know has been working since 2002 or so... What is missing is a configuration tool with GUI for the average user (like me).

Then again as a normal user I would expect the choice to select more than one sound to be in the right hand side of QJacjCtl's set-up window...

How about it?

Simon

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rncbc's picture

Re: New feature request - multiple sound cards with QJackCtl

I'm afraid that feature might not be a good idea. That is, it would be greatest if it worked for jackd, in general.

You know, that jack was designed to work against only one sound-card device and its ALSA backend driver is coded explicitly with that rule in mind, so to speak. You can of course make it work with combined virtual devices given that you can get it all correct magic on the asoundrc configuration file.

It's all highly tricky, unreliable and prone to too many disparate problems that depends on each particular device setup and configuration. Not speaking that you'll have to tune for high-latencies, something that JACK is not well suited or overkill :) Not easy, not even for the expert ALSA technician which I am not ;)

Cheers

What about just support for alsa_in and alsa_out.

What about having support in qjackctl for alsa in/out and for doing the sorts of setups described
at the alsa wiki

for people with firewire cards to be able to use them as general purpose soundcards in linux.

Also it'd be nice if qjackctl used the device name instead of hw:1 so when cards are plugged in in different orders then the config persists as decribed at the fedora musicians guide to using jack

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