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Rockbox mail archiveSubject: Re: Descrambler for multimediaRe: Descrambler for multimedia
From: Josh Nisly <joshn_at_invtools.com>
Date: Thu, 08 Jan 2004 14:06:57 -0600 Does this mean that the focus for new Rockbox "expansion" will change from mp3 players from other manufacturers (Neo, xclef players) to Archos multimedia players? Björn Stenberg wrote: >Hi. > >My little christmas project has paid off. I just committed an update to 'descrambler' which supports descrambling Multimedia firmware files. I'll commit a new 'scrambler' tomorrow. > >The Multimedia firmware files are compressed using a custom token packing algorithm, and then XORed with a 32-byte string. The descrambler tool finds this string automagically, simply by assuming that 0 is the most common byte in the plaintext. A simple statistical analysis then produces the string. > >The compression was trickier, but thanks to it not being very efficient (gzip compresses the firmware to about 60% of the .ajz size) there was plenty of plaintext to look at in the compressed data. > > > Received on 2004-01-08 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |