(already posted this in the rtcw forum by accident)
I’ve been trying to find a way to read the ET demo files (*.dm_83). I’ve already managed to get the individual packets (seqno/length/data) from the demos but I haven’t got a clue how to decompress or decode the packetdata. I think they are encoded with some kind of huffman coding algorithm, is that correct?
If someone could point me in the right direction, or give me some help it would be very much appreciated.
yes
but it will be a real pain in the ass to decode them without engine source, unles you’ve got a lot of patience
i’ve got a bit of patience, but I still haven’t got a clue how to decompress the packets 
i found a program that reads quake3 demos (http://www.slipgate.de/projects/argus.html), and i’ve found some code that should decompress (q3) demo packets http://aluigi.altervista.org/papers.htm (scroll down to Quake 3 engine huffman algorithm 0.2)
I haven’t been able to decompress the data with the q3 huffman algorithm. My guess would be that the frequency count for the bytes isn’t correct (which results in an incorrect generated huffman tree). Anyone else got a suggestion?