[Vorbis] New to audio compression

[Matt Rogers]

Hi everyone, this is the first time I've ever tried to program sound 
using compressed audio; I've written many apps that play "normal" PCM 
.wavs.  The best I've done so far is I used vorbisfile to play a .ogg, 
but I'd like to get a bit more advanced.

What I'm currently trying to do is figure out Ogg so I can eventually 
add Vorbis and Speex support to my applications.  I'm having trouble 
figuring out exactly how Ogg works though, and any tutorials I've come 
across online use vorbisfile.  Besides the SDK docs, can anyone point me 
in a direction that may help me?  At this point all I'd like to do is 
parse through an Ogg file without regard for the actual CODEC being used.

Thanks!