Feature request: mp4 support

As a .NET Core developer, I've been struggling to read audio from a mp4 file. Why would you ask? Well, I've been trying to basically play mp4 files and, while that's working, I can't seem to be able to get audio to work for some reason. 

So now I'm using this library (which works great) to load in a different file (an mp3 extracted from the mp4), but I'd love to have support for mp4 files too!