Path: chuka.playstation.co.uk!tjs From: tjs@cs.monash.edu.au (Toby Sargeant) Newsgroups: scee.yaroze.freetalk.english Subject: Re: Compressing TIMs... Date: 29 Sep 1998 22:32:13 GMT Organization: PlayStation Net Yaroze (SCEE) Lines: 24 Message-ID: References: <36101E37.52C5@mundivia.es> <3610ADC8.27DA@mundivia.es> NNTP-Posting-Host: longford.cs.monash.edu.au X-Newsreader: slrn (0.9.4.3 UNIX) On Tue, 29 Sep 1998 11:52:08 +0200, Javier Ventoso wrote: >Toby Sargeant wrote: >> Maybe it's an idea to port zlib to the playstation. it does adaptive >> huffman encoding and lzw compression. the source is freely available, >> and it's the same algorithm that gzip and pkzip use. it'd save you >> a lot of work, in the long run. >> >> Toby. > >I can't use Huffman/LZW 'standard' method, it needs a lot of PSX memory, >I >must code some optimizations and rebuild it a lot. Compression takes a lot of memory, but decompression takes very little memory, because all you need is the huffman tree and a table of pointers that reference the already decompressed data. Port doesn't necessarially mean 'make compile on the playstation'; it means 'make into a workable piece of code on the playstation'. This may well mean looking at the inefficiencies in zlib, and rewiting areas to have a smaller memory footprint. it might also mean linking it with GNUmalloc, rather than the playstation malloc, which I'm pretty sure will leave you with less memory fragmentation, and effectively more memory to play with. Toby.