Comment 4 for bug 1172299

I have just read into JACK and Portaudio API.

I am afraid that the quested function is out of scope of Portaudio.
Port audio is a simple wrapper around many APIs for a common interface. The requested function, to expose static audio port to Jack, is a particularly Jack function. Once Implemented in Port audio it is only suitable for Jack.
But you can give it a try on the portaudio mailing list <email address hidden>.

If I have understand it right, there are two classes of Jack applications:
1) Instant port applications with self connecting like Mixxx/Portaudio
2) Static port applications like Meterbridge

Portaudio (1) is Looking for exposed Jack ports and registers the counter port instantly on connection. This way there is no external connection tool required. But if the Portaudio app is not connected it has no ports.

Meterbridge (2) does nothing without any connection but exposes all its ports to Jack just after startup.

But it is possible to trick Mixxx, if you create Mixxx Jack ports by connecting to random jack ports from the Mixxx config GUI.
And then change the connection by an external connection tool.

http://dis-dot-dat.net/index.cgi?item=/jacktuts/starting/

I think th Jack API is really easy. And since Jack is also OS independent it should be not hard to Implement a native SoundDeviceJack. But it is a lot of work anyway. We can toggle between our own hardware connection dialog and Simply expose all Mixxx Ports to jack.