AdPlug module and AudioStream support

[compbluewiz]

I understand this won't be a priority, but just wanted to share an idea.
It would have been cool if Godot had AdPlug sound player library as a module and AudioStream support for playing back files going through it. It's probably quite easy to add for somebody familiar with C++ and Godot audio subsystem, the library is in C++ and has LGPL license, has like one dependency (libbinio, in the same place), and it just outputs PCM data from some old OPL2/3 sound chip oriented file formats, which could be used in AudioStream.
It could allow for some interesting background music :)

[Calinou]

and has LGPL license

This license can't be used in core Godot, as per the Best practices for engine contributors.

Either way, this can be implemented as an add-on, as shown by Godot MIDI Player.