Author Archives: Multimedia Mike

Ode to the Gravis Ultrasound

WARNING: This post is a bunch of nostalgia. Feel free to follow along if you recall the DOS days of the early-mid 1990s.

Also, if you’re interested in the Gravis Ultrasound Experience CD-ROM, you can download the compressed ISO image here (137 megabytes). This only contains the data track as a .ISO file. However, the Internet Archive hosts the disc in CUE/BIN format which includes all the data tracks.

I finally let go of my Gravis Ultrasound MAX sound card a little while ago. It felt like the end of an era for me, even though I had scarcely used the card in recent memory.



The Beginning
What is the Gravis Ultrasound? Only the finest PC sound card from the classic DOS days. Back in the day (very early 1990s), most consumer PC sound cards were Yamaha OPL FM synthesizers paired with a basic digital to analog converter (DAC). Gravis, a company known for game controllers, dared to break with the dominant paradigm of Sound Blaster clones and create a sound card that had 32 digital channels.
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Multimedia Exploration Journal: The Past Doesn’t Die

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.

PC Video Conferencing in the Year 1999

Remember Intel’s custom flavor of H.263 cleverly named I.263? I think I have finally found an application that used it thanks to a recent thrift shop raid— Intel Video Phone:



The root directory of the disc has 2 copies of an intro.avi video. One copy uses Intel Indeo 3 video and PCM audio. The other uses I.263 video and an undetermined (presumably Intel-proprietary) audio codec — RIFF id 0x0402 at a bitrate of 88 kbits/sec for stereo, 22 kHz audio. The latter video looks awful but is significantly smaller (like 4 MB vs. 25 MB).

This is the disc marked as “Send it to a friend…”. Here’s the way this concept was supposed to operate:

  • You buy an Intel Video Phone Camera Pack (forgotten page courtesy of the Internet Archive) which includes a camera and 2 CDs.
  • You install the camera and video phone software on your computer.
  • You send the other CD to the person whom you want to be able to see your face when you’re teleconferencing with them.
  • The other party installs the software.
  • The 2 of you may make an internet phone call presumably using commodity PC microphones for the voice component; the person who doesn’t have a camera is able to see the person who does have a camera.
  • In a cunning viral/network marketing strategy, Intel encourages the other party to buy the physical hardware as well so that they may broadcast their own visage back to the other person.

If you need further explanation, the intro lady does a great job:



I suspect I.263 was the video codec driving this since Indeo 3 would probably be inappropriate for real time video applications due to its vector quantizing algorithm.

Deobfuscation Redux: JavaScript

Google recently released version 12 of their Chrome browser. This version adds a new feature that automatically allows deobfuscating obfuscated JavaScript source code.

Before:



After:



As a reverse engineering purist, I was a bit annoyed. Not at the feature, just the naming. This is clearly code beautification but not necessarily deobfuscation. The real obfuscation comes not from removing whitespace but from renaming variable and function names to terse 1- and 2-letter identifiers. True automated deobfuscation — which entails recovering the original variable and function identifiers as well as source code comments — is basically impossible.

Still, it makes me wonder if there is any interest in a JavaScript deobfuscator that operates similar to my Java deobfuscator which was one of the first things I published on this blog. The general idea is automatically replace function names with random English verbs (since functions correspond to actions) and variable names with random animal names (I decided “English nouns” encompassed too broad a category of words). I suspect the day that someone releases a proprietary multimedia codec in a pure (though obfuscated) JavaScript format is that day that I will try to accomplish this, if it hasn’t been done already.

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