Just so you guys know, twitch doesn't officially support HE-AAC, and I won't be distributing HE-AAC plugins directly because they'd most likely be non-free. I'm actually only going to be distributing the FFmpeg experimental AAC encoder directly with the newer version, the others will have to be obtained by users manually (at their own discretion as per GPL). It will most likely be still quite possible to get them though, especially if you build your own ffmpeg as well for example