SPU work started (Patreon)

Hello everyone,

just a very quick update today. 

I started with Sound development about 2 weeks ago and was able to have the SPU feature complete in my emulator this week.

Yesterday I started with integrating that knowledge into the FPGA core. The very first step is done: 24 channel ADPCM decoding works now. With all other SPU features missing and some bugs in, it still sounds awful, but at least the FPGA core now produces some audio.

I will commit the code and provide a Testbuild as soon as I can be sure it doesn't freak out constantly, so give it a week or two.

Please note: CD Audio and ADPCM CD streaming is not part of the SPU and will be done once the SPU part is finished. Many games use audio streaming for background music, FMVs or dialogs, so these games will only have sound effects with SPU until then.

Have fun!