Breaking Eggs And Making Omelettes

Topics On Multimedia Technology and Reverse Engineering


Studying Xbox Multimedia

October 29th, 2006 by Multimedia Mike

…at least, that’s what I would like to do. I bought a used Xbox game nearly 2 years ago with the intention of opening up the disc and studying the contents for interesting multimedia formats. I picked up a few more titles some months ago because I heard these games had some unique multimedia targets. Today, close to 5 years after the Xbox’s initial launch, I tried to examine the disc contents. I ran into a few problems.

I had always heard that Xbox discs have a standard DVD-video structure at the front in order to accommodate the eventuality that the disc may be placed into a standard DVD player. Sure enough, treating the disc like a DVD shows a 13-second, totally X-treme Xbox video followed by a still screen instructing the user, in several languages, to play the disc in the proper game console.

If you use standard CD/DVD system tools to study the Xbox disc, it will be reported as having 6,992 2048-byte sectors, a little over 14 megabytes of DVD-video data. This page on Xbox-Linux describes the Xbox DVD filesystem (XDVDFS) format. However, the markers discussed in that document (“MICROSOFT*XBOX*MEDIA”) do not occur in this 14-megabyte data segment. I imagine the game data starts immediately after this segment. As the document explains, the Xbox DVDs have a fraudulent TOC which tells standard DVD-ROM drives that the disc is much shorter than it actually is. Trying to seek past that point manually just results in an unceremonious EOF.

A brief perusal of BitTorrent sites reveals that many people have absolutely no trouble ripping Xbox games for the purpose of distribution. How do they do it? Apparently, by modding an Xbox, running Linux on it, logging into the Xbox, loading a game disc into the Xbox’s drive, FTP’ing to another computer, and reading the raw game sectors from the disc using the Xbox’s drive, which apparently uses a different set of rules for reading. Not being in possession of an Xbox and having no desire to invest in one at this time, I am at a bit of a loss to study these discs, unless there is a solution I am overlooking.

Based on the filesystem format doc, I am quite confident I could write a FUSE module for browsing the filesystem in short order, based largely on my gcfuse code.

Posted in Game Hacking, xbox | 2 Comments »

It’s A Classic

October 28th, 2006 by Multimedia Mike

Behold– a printed and bound copy of the Apple QuickTIme specification. It’s okay to be jealous:

Vintage QuickTime Spec
click for larger image

It’s a bit outdated (version 2.2 from April, 1996), but that only adds to its value. I found it at the top of a scrap pile at work. What fortune! I’m certain this would fetch a handsome price on eBay but I am unwilling to part with such a rare jewel. That there are no similar auctions on eBay for the purpose of price comparison is just further evidence of the manual’s rarity.

Posted in General | 2 Comments »

MPlayer 1.0rc1 Reviewed

October 27th, 2006 by Multimedia Mike

MPlayer recently blessed their latest 1.0 release candidate. As some readers may know, MPlayer is where I cut my teeth in practical multimedia hacking– that was 5 years ago, right about this time of year. Makes me sentimental just to think about it.

MPlayer logo

Other commitments have kept me from coming up with anything interesting for this blog. Instead, I thought I would see how well this release fulfills my original goals from when I embarked on this multimedia hacking adventure so many years ago. It runs on Linux, is free, and is open source, so all of those bases are covered. Now let’s see if it’s simple to install and can handle any file I throw at it (I’ll defer on the GUI goal for the time being).

Read the rest of this entry »

Posted in Open Source Multimedia | 13 Comments »

GameCube Multimedia Review

October 6th, 2006 by Multimedia Mike

Poking around on a number of Nintendo GameCube games, I have found a pretty consistent mix of FMV formats. In due time, these will need to be entered into the MultimediaWiki:

  • THP files seem to be the most prevalent
  • H4M files have the markings of a hierarchical vector quantizer (like the letters ‘HVQ’); HVQ is also used in Sorenson Video 1 and LucasArts video
  • Electronic Arts games have a VID format which has similar markings as a number of their other evolved game multimedia formats
  • One game has 11,500+ Ogg Vorbis files; some of them appear to correspond via base filename to files with the extension .cib; I tend to think that these are corresponding video files
  • Sofdec files, as commonly seen on Sega Dreamcast games
  • DSP files, often paired as L and R files for stereo effect
  • occasional BIK files

Plus, there are a number of other audio files, probably encoded with a custom ADPCM format common on GameCube games.

Posted in Game Hacking, Nintendo | 3 Comments »

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