Demo Structure

[sPlOrYgOn]

Does anyone have any information about the Half-life demo structure? I've been comparing lots of different demos to try to figure out it's structure. So far I've found out that it begins with "HLDEMO", a 32bit int for Demo Version, a 32bit int for Protocol Version, a 260 char string for map name, and a 260 char string for mod directory name. Everything after this point I have not figured out. I looked around the web and didn't find too much. I also looked at the quake 1 source code for demo recording, but I can't seem to connect much to the hl demo structure.. Looking at the HLSDK seems doesn't seem to tell much about the demo structure. Any information would be very appreciated.
[edit]
then I found this http://www.machinima.com/opendemo/od-misc.html
still looking at the perl code.. (dunno much, if any, perl)
[/edit]

[sfx1999]

There should be something in the SDK about this. If there isn't, you are going to have to use Quake's source and hack the new stuff. It is probably extra joints and render properties mainly.