Question on Compression Formats

Discussion in 'Technical Discussion' started by Neo Majin, Feb 22, 2007.

  1. Neo Majin

    Neo Majin

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    So, I was recently looking into the 1989 Genesis game, Phantasy Star II. Sure enough, this game uses Nemesis graphics compression for the area graphics, like many Genesis games have. However, only Nemesis graphics have a searcher for them, as far as I know. It seems possible to me that the Kosinski and Enigma formats could be used in this game, as they seem to be common compression formats in Sega proprietary games. I find it difficult to find information on these formats... are there any sort of signs, such as a header or something, that could point me in the direction of finding compressed information, or will I have to resort to trial-and-error corruption? Are there any other decent ways to find data in Genesis games?
     
  2. Tweaker

    Tweaker

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  3. drx

    drx

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    Most decompression algorithms don't vary between games (eg. the Kosinski decompression routine is unlikely to change in games where it is used), so you could try runnign a search for some characteristics of the decompression routines in the games (and it's very easy to do so, since most decompression routines are heavily optimized and often use obscure instructions etc)

    Sometimes they do change though, like with the Nemesis format (though it wasn't such a big change, in over 4 years between Sonic 1 and Ristar, there has been just a few minor changes that sped up the decompression process, same with Enigma btw), but it shouldn't be much of a problem.
     
  4. Mecha Sonic

    Mecha Sonic

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    I wonder, do any of you know what compression algo are used in the game Wonderboy in Monsterworld. It's a Megadrive game I like for the music, but I'm not sure if anyone else does. I've been trying relentlessly to find out what the music data is compressed in. I have found where the Z80 driver is located. And where some music data is aswell. It seems to have headerless music. I've tried 0603 0503 0703 and fuck all turned up, I'd really love to find out, as I want to port a couple to my hack.

    Tweaker, are you able to sort something out? I've tried but, failed.

    Z80 driver starts from $98000 - (I still can't find where it ends at).
    I suspect music pointers are at $99B00 - but I can't clarify it.

    Here's the ROM http://www.freewebs.com/tigertank1/Wonder%...20%5B%21%5D.bin
     
  5. Cinossu

    Cinossu

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    Wonderboy in Monster World uses a different sound driver to that of Sonic games. http://gdri.smspower.org/wiki/index.php/Me...und_Engine_List lists it as "Wonder Boy V", which two other games have: Monster World IV and Mega Bomberman. Sonic uses SMPS. If you specifically just want the music from Wonderboy in Monster World, your best bet right now is to use a VGM pack as reference, SonicQX to get voices from savestates, and recreate the music from scratch yourself.

    I do commend you for your good taste in game music (and games), though. Wonderboy in Monster World has a great soundtrack.
     
  6. nineko

    nineko

    I am the Holy Cat Tech Member
    How hard would it be to figure out how the other music drivers work? After all, someone had to figure out about Sonic's...
    If someone can help me in this task I may be able to write a converter (or more than one), if such a thing is possible, and music porting between any Genesis game would become possible... I now used Snow Bros as a reference because I LOVE that soundtrack, but I'm sure other people (like obviously Mecha Sonic) would appreciate more research on other music drivers... Just my two cents. Do any of the Music Gods here (I'm looking at you, Tweaker and Saxman) have some tips on this?

    Also, I see how this post may be a bit off topic in a "Compression Formats" topic, so if a split is needed please do so, I was just continuing from the previous post.
     
  7. Mecha Sonic

    Mecha Sonic

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    Thanks mate. I'm glad to hear it's not just one who thinks that it rocks!

    I've been studying the driver like mad, to figure it out a bit. I started a disassembly of it just recently, but that hasn't revealed anything useful yet. I have tried getting the voices from a savestate with Qx, but it doesn't seem to be that reliable. I ripped them manually to a file, but they're just noise.

    Oh and BTW, what does SMPS stand for?
     
  8. Tweaker

    Tweaker

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    Sample Music Playback System.

    I'm assuming it's the stock driver that comes with the Genesis SDK.
     
  9. ICEknight

    ICEknight

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    Also, a music extractor would be sweet. It would make looking for "lost" music a lot easier than what I had to do with the Sonic 3D proto.


    ...Then, once those formats are as documented as to make the converter, one could hopefully await for a music plugin to play them directly without the need for GYMs, VGMs, etc.