Decoding DDR arcade .DAT file by SSGotenksUFO at 9:47 PM EDT on July 26, 2010
Hey there. I was wondering if someone could take a look at this file. I popped in the disc to an arcade DDR game (Dance Dance Revolution 4thMIX Plus) and was looking around for where the game's audio is stored.
I have a strong suspicion that each one of these files represents one of the songs in the game. There are exactly 150 songs in this version of DDR, and there are exactly 150 of these files around this size. The disc also has 150 smaller .DAT files, which I'm sure represent the 10 sec. samples played on the song select screen. There are also a few random .DAT files, which probably make up the menu music.
Please let me know what you can do with it. Thanks.
I'm sure they're highly compressed, they have to fit 150 songs on a CD. That doesn't include the other data. Later DDR games had about 300 songs on 1 disc.
By highly compressed I mean with information theory-flavored compression, rather than ADPCM coding or other low bitrate stuff. I don't see any patterns in this one file to have anything to go on.
Knurek told me something about encrypted MP3 on DDR games and there really isn't anything you can do since it's hardware decrypted.
EDIT: Here it is
<@bxaimc> I wonder if DDRMAX2 (Arcade) is encrypted <@bxaimc> can't make anything out of these files... <@Knurek> it is, bxaimc <@Knurek> had a talk about it with RBelmont <@Knurek> all system 573 digital games are <@Knurek> MPEG chip on the hardware with some programmable FPGAs <@Knurek> i.e. encrypted MP3 <@bxaimc> hardware or software decryption? <@Knurek> hardware <@Knurek> btw, are those playable in mame? <@Knurek> no, wait <@Knurek> they can't be - no decryption :) * @Knurek is an idiot this late at night (last part is just for giggles :P)
You can try asking on some Stepmania forums. To my knowledge, there are simfile packs from the arcade games with high quality mp3s - maybe they know of a way to decrypt the arcade datafiles.