|
Rockbox mail archiveSubject: Re: Gmini Firmware questionRe: Gmini Firmware question
From: Magnus Holmgren <lear_at_algonet.se>
Date: Wed, 31 Dec 2003 14:51:50 +0100 Laurent Giroud wrote: > The first missing point is figuring the compression algorithm. Gzip > can't compress the firmware file by more than 2 or 3 percents which > is a good indicator and there's a 'CCOD' chunk which might stand for > "Compressed code" and one 32 bits field yields a value which is > approx 2 times bigger than each firmware file and would be a very > good candidate for the decompressed firmware size. Just as a side note, but gzip not being able to compress it much doesn't necessarily mean that the file was compressed to begin with. A simple "encryption" can have that effect too (I saw it with a file that was "decrypted" by doing something like <byte n> = <byte n> XOR <byte n-1>, with a seed for byte -1). -- Magnus HolmgrenReceived on 2003-12-31 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |