Unable to add a second audio input source

[dforsi]

I have two sound cards (one is builtin on the motherboard of my PC and the other is embedded in my radio), I can add an audio source and select either one. I would like to add both as separate sources for differente demodulators, but the sampling device dialog allows only to add one audio source.

[f4exb]

Probably due to the way the Audio plugin is handled as if it was an actual hardware device. This does not happen with KiwiSDR for example.

[f4exb]

Issue is here: https://github.com/f4exb/sdrangel/blob/master/plugins/samplesource/audioinput/audioinputplugin.cpp#L96 it should be listed as a "BuiltInDevice"

Conversely the audio output plugin is correctly listed: https://github.com/f4exb/sdrangel/blob/master/plugins/samplesink/audiooutput/audiooutputplugin.cpp#L91