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• Metal Gear Solid VP3 Easter Egg

  4 août 2011, par Multimedia Mike — Game Hacking

  Metal Gear Solid : The Twin Snakes for the Nintendo GameCube is very heavy on the cutscenes. Most of them are animated in real-time but there are a bunch of clips — normally of a more photo-realistic nature — that the developers needed to compress using a conventional video codec. What did they decide to use for this task ? On2 VP3 (forerunner of Theora) in a custom transport format. This is only the second game I have seen in the wild that uses pure On2 VP3 (first was a horse game). Reimar and I sorted out most of the details sometime ago. I sat down today and wrote a FFmpeg / Libav demuxer for the format, mostly to prove to myself that I still could.

  Things went pretty smoothly. We suspected that there was an integer field that indicated the frame rate, but 18 fps is a bit strange. I kept fixating on a header field that read 0x41F00000. Where have I seen that number before ? Oh, of course — it’s the number 30.0 expressed as an IEEE 32-bit float. The 4XM format pulled the same trick.

  Hexadecimal Easter Egg
  I know I finished the game years ago but I really can’t recall any of the clips present in the samples directory. The file mgs1-60.vp3 contains a computer screen granting the player access and illustrates this with a hexdump. It looks something like this :

  
  
  

  Funny, there are only 22 bytes on a line when there should be 32 according to the offsets. But, leave it to me to try to figure out what the file type is, regardless. I squinted and copied the first 22 bytes into a file :

   1F 8B 08 00   85 E2 17 38   00 03 EC 3A   0D 78 54 D5
   38 00 03 EC   3A 0D
  

  And the answer to the big question :

  $ file mgsfile
  mgsfile : gzip compressed data, from Unix, last modified : Wed Oct 27 22:43:33 1999
  

  A gzip’d file from 1999. I don’t know why I find this stuff so interesting, but I do. I guess it’s no more and less strange than writing playback systems like this.

• Who Invented FLIC ?

  26 mai 2011, par Multimedia Mike — Multimedia History

  I have been reading through “All Your Base Are Belong To Us : How 50 Years of Video Games Conquered Pop Culture” by Harold Goldberg. Despite the title, Zero Wing has yet to be mentioned (I’m about halfway done).

  
  
  

  I just made it through the chapter describing early breakthrough CD-ROM games, including Myst, The 7th Guest, and The 11th Hour. Some interesting tidbits :

  The 7th Guest
  Of course, Graeme Devine created a new FMV format (called VDX, documented here) for The 7th Guest. The player was apparently called PLAY and the book claims that Autodesk was so impressed by the technology that it licensed the player for use in its own products. When I think of an Autodesk multimedia format, I think of FLIC. The VDX coding format doesn’t look too much like FLIC, per my reading.

  Here’s the relevant passage (pp 118-119) :

  Devine began working on creating software within the CD-ROM disk that would play full-motion video. Within days he had a robust but small ninety-kilobyte player called PLAY that was so good, it was licensed by Autodesk, the makers of the best 3-D animation program at the time. Then Devine figured out a way to compress the huge video files so that they would easily fit on two CD-ROMs.

  Googling for “autodesk trilobyte play program” (Trilobyte was the company behind 7th Guest) led me to this readme file for a program called PLAY73 (hosted at Jason Scott’s massive CD-ROM archive, and it’s on a disc that, incidentally, I donated to the archive ; so, let’s here it for Jason’s tireless archival efforts ! And for Google’s remarkable indexing prowess). The file — dated September 10, 1991 — mentions that it’s a FLICK player, copyright Trilobyte software.

  
  
  

  However, it also mentions being a Groovie Player. Based on ScummVM’s reimplementation of the VDX format, Groovie might refer to the engine behind The 7th Guest.

  So now I’m really interested : Did Graeme Devine create the FLIC file format ? Multimedia nerds want to know !

  I guess not. Thanks to Jim Leonard for digging up this item : “I developed the flic file format for the Autodesk Animator.” Jim Kent, Dr. Dobbs Magazine, March 1993.

  The PLAY73 changelog reveals something from the bad old days of DOS/PC programming : The necessity of writing graphics drivers for 1/2 dozen different video adapters. The PLAY73 readme file also has some vintage contact address for Graeme Devine ; remember when addresses looked like these ?

  If you have any comments, please send them to :
  	Compuserve : 72330,3276
  	Genie : G.DEVINE
  	Internet : 72330,3276@compuserve.com
  

  The 11th Hour
  The book didn’t really add anything I didn’t already know regarding the compression format (RoQ) used in 11th Hour. I already knew how hard Devine worked at it. This book took pains to emphasize the emotional toll taken on the format’s creator.

  I wonder if he would be comforted to know that, more than 15 years later, people are still finding ways to use the format.

• Multimedia Exploration Journal : The Past Doesn’t Die

  12 juillet 2011, par Multimedia Mike — Game Hacking

  New haul of games, new (old) multimedia formats.

  Lords of Midnight
  Check out the box copy scan for Lords of Midnight in MobyGames. In particular, I’d like to call your attention to this little blurb :

  
  
  

  Ahem, "Journey through an immense world — the equivalent of 8 CD-ROMs." Yet, when I procured the game, it only came on a single CD-ROM. It’s definitely a CD-ROM (says so on the disc) and, coming from 1995, certainly predates the earliest DVD-ROMs (which can easily store 8 CD-ROMs on a disc). Thus, I wanted to jump in a see if they were using some phenomenal compression in order to squeeze so much info into 600 or so megabytes.

  I was surprised to see the contents of the disc clocking in at just under 40 megabytes. An intro movie and an outro movie account for 75% of that. Format ? None other than that curious ASCII anomaly, ARMovie/RPL with Escape 122 codec data.

  Cyclemania

  
  
  

  Cyclemania is one of those FMV backdrop action games, but with a motorcycle theme. I had a good feeling I would find some odd multimedia artifacts here and the game didn’t disappoint. The videos are apparently handled using 3-4 discrete files per animation. I’ve documented my cursory guesses and linked some samples at the new MultimediaWiki page.

  Interplay ACMP
  This is unrelated to this particular acquistion, but I was contacted today about audio files harvested from the 1993 DOS game Star Trek : Judgment Rites. The files begin with the ASCII signature "Interplay ACMP Data". This reminds me of Interplay MVE files which begin with the similar string "Interplay MVE File". My theory is that these files use the ACOMP compression format, though I’m still trying to make it fit.

  Wiki and samples are available as usual if you’d like to add your own research.