Currently, PipeWire has implementations of a majority of audio transfer methods, such as JACK, Alsa, and PulseAudio.
AS FAR AS I KNOW none of those three support capturing an individual app's audio, but PipeWire does.
A workaround that may work for now (when the pngtuber feature is added) is redirecting your audio application you want to capture to a sink, which vpuppr can capture.
Mainly helps with #122.
Currently, PipeWire has implementations of a majority of audio transfer methods, such as JACK, Alsa, and PulseAudio. AS FAR AS I KNOW none of those three support capturing an individual app's audio, but PipeWire does.
Assuming JACK allows this, a relevant PR may be https://github.com/godotengine/godot/pull/35613, as it implements JACK support.
A workaround that may work for now (when the pngtuber feature is added) is redirecting your audio application you want to capture to a sink, which vpuppr can capture.