Support PulseAudio for audio capture

[magiruuvelvet]

Feature request

What problem does this feature solve?

Capture audio streams from PulseAudio sinks. This allows you to capture the audio stream which is sent via Bluetooth without setting up solutions like BlueAlsa or virtual ALSA cards. BlueAlsa and PulseAudio can't be used at the same time due to hardware limitations. It's also not ideal if PulseAudio is tightly integrated into your system and acts as the default sound server.

What does the proposed API look like?

Be able to select PulseAudio sinks in the Capturing Hardware -> Audio Capture interface.

How should this be implemented in your opinion?

As a new audio grabber in libsrc/grabber/audio using libpulse.

Are you willing to work on this yourself?

I might give this a try myself. Could you please give me a brief overview on how the audio grabber architecture works? Anything I need to pay attention too? I saw in another feature request that latency/delay could be a problem.