Halo 2 compression!

SEHF · Post by **SEHF** » Sat Oct 30, 2004 6:53 pm

It seems that Halo 2 uses a new form of compression, which is patented by Jean-Loup Gailly.

The SP and MP maps are now much larger then the ones found in Halo, so a new compression format is used to uncompress the maps into the cache files. Here's a link to the type of compression:

http://www.teaser.fr/~jlgailly/

Halo 2 probably has a slightly modified version of this gzip, but they are still pretty similiar. This will be useful for uncompressing halo 2 maps for modding.

By the way, this is not leakage. I got the answer from one of the bungie employees, on bungie.net. Its a topic about how you can ask the engineer behing halo 2 about the halo 2 engine. So there!

Digital71 · Post by **Digital71** » Sat Oct 30, 2004 8:16 pm

Interestin info (both topics). Thanks for sharing.

mrhyperpenguin · Post by **mrhyperpenguin** » Sun Oct 31, 2004 4:55 am

and what makes you think this? ive gone over the maps and noticed that some of the map (a fair amount) isnt compressed

SEHF · Post by **SEHF** » Sun Oct 31, 2004 8:10 am

I don't know much about it, but that's what I found out from the topic at bungie.net. Its under the New Mombassa forum.

The original halo MP compressed maps were about 25 megs. When uncompressed they were about 47 megs.

The halo 2 MP compressed maps are about 45 megs. When uncompressed they are about 180 megs!

mrhyperpenguin · Post by **mrhyperpenguin** » Sun Oct 31, 2004 5:50 pm

the old halo used zlib compression, and h2 compressed is 45 and decompresses (maybe) at 80

SEHF · Post by **SEHF** » Mon Nov 01, 2004 4:16 am

Yeah, sorry.

I made a mistake about the 180 mb uncopressed. That was something else.

Maybe the Gzip is used for downloaded content. I don't know, really.
Its just what was posted in the topic. It has to be used somewhere, if he said it.