Tech Spec for Divx codecs

[TelemachusMH]

Does anyone know where I can find tech specs for the divx codecs and how input is put into the codec via the compdata command in vdub? I have the information for divx 4.11 but it doesn't seem to work for 4.12. I would like to find the info for 4.12 and others to come if possible;)

Thanks,
TelemachusMH