loopback device for system sound (sound proxy)

[Daniel Schürmann]

It would be a nice feature, if mixxx is able to catch the sound output of other application and use it as a sound source for mixing.

Today on my Linux machines mixxx occupies the whole sound output and system sound is muted.
A good behaviour in general I think, but If you want to mix sound from special external sources you need a additional Hardware.

Some use cases:
* Showing a video
* playing songs which can only be played by special players due to DRM
* playing special formats like mid, sid or ac3
* playing online streams from tape.tv simfy or last.fm

A workaround could be, to connec Mixxx to PulseAudio, but I have not managed to get this working. (separate Bug)

Is it possible, to register mixxx as sound Output for PulseAudio?

[RJ Skerry-Ryan (rryan)]

I've been thinking that we may need to provide a native PulseAudio backend or possibly build PulseAudio support into PortAudio. The user experience right now with pulse-enabled Linux systems is very bad.

If we did, that would possibly let us present ourselves as an audio input as well.

[William Good (bkgood)]

I'm interested in looking into writing a Pulse backend into PortAudio over my holiday break, so I'm pinning this on myself. It would definitely be an improvement for the Ubuntu users, and my understanding is that Pulse at least has the capability of not-too-horrible latency.

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/6136