Re: [Jack-Devel] backend switching - another way

Hi,

On Monday 21 February 2011 19:53:03 Fons Adriaensen wrote:
> I've been musing for a long time over the idea 'what if Jack ports
> were persistent' ? In other words, if they could exists irrespective
> of the application that uses them is running or not.
> 
> This has some far-reaching consequences of course, but there is
> subset of this idea that is not as mad as it seems (IMHO).
> 
> ** What if physical ports were persistent ? **

I like the idea!

Still I would like to extend the question: What if there where virtual ports?

These virtual ports would be configured in a configuration(-file) if present or 
by the first client providing these. If no config-file was there to make the 
ports persitent forever, they would stay as long as jack is running, 
regardless of the backend actually in use.

I would very much like to remove the distinction between "clients" and 
"backends". After all a traditional client (be it a separate process or an in-
server-client) is just a client that is capable of free-wheeling. And a 
backend is just an in-server-client that is not (necessarily) free-wheeling 
capable but definitely master-clock-capable.
Thinking about it, even this is not true, the "null"-backend would be the 
master-clock for freewheeling. Thus hardware-clients would be not-
freewheeling-capable. And as long as all clients are either synced or at least 
have resampling-capabilites (for unsynced hardware-clients), there is no 
difference between clients and backends...

Some benefits of this would be:
 - Several backends running at the same time (like alsa-on-the-pci-soundcard, 
alsa-on-usb-soundcard and firewire).
 - Clients defining the "master-out" ports to provide some studio-monitoring-
control before actually sending the data to whatever hardware there is.
 - Of course persistent setups independant of the actual hardware. (Like 
switching from playing-to-usb to playing-to-firewire to suspend to playing-on-
network depending on available hardware. And don't forget the intermediate 
step of playing-to-file...)
 - Effect-switching on the fly: Define a virtual port "Reverb" and run jack-rack 
with appropriate effects. Then switch that to some IR without reconnecting 
ports or changing (ardour-/qtractor-/bla-)sessions.

Have fun,

Arnold

1298323061.12525_0.ltw:2,a <201102212217.21211.arnold at arnoldarts dot de>