I'm hoping to release an alpha test version of Ogg Frog around the middle of February. Leading up to that, I'll be posting a series of diaries outlining Ogg Frog's architecture - it's audio architecture in particular - in my Kuro5hin diary. After some further editing, these will become The Ogg Frog Programmer's Guide that will be supplied along with the source code.
The first entry is:
ZPCMQueue is a FIFO buffer for storing decoded PCM samples. It's implemented as a two-ended circular buffer.