SpritesMind.Net

I've uploaded the latest source for SCAT to SoureForge. You can get it here .

This release adds visualizers for file structure as well as clip layout structure. The file structure visualizer allows you to see how chunks are interleaved in each file, and the clip layout visualizer represents the ...

I know there incomplete documents on the SGA format out there already, do you plan on making a document that is more complete? I would love to see some of the ways they compressed the data and such.

Altogether there are 23 types of data chunk that I know of, and SCAT can correctly process 20 of ...

I've been working on SCAT off and on over the last several months, and I've just released a new version. The program is now capable of decoding basically every media file from the games produced by Digital Pictures for the Mega CD (32X). Also new in this version is the ability to play back files in ...

It looks like the program is repointing to a location offset from address $00015DB4. I checked that area of memory using an emulator, and it's always empty. However, using all zeroes in my code leads to graphics glitches in the output.

I'm stumped. Can I get some help on this?
It's right under ...

It looks like the program is repointing to a location offset from address $00015DB4. I checked that area of memory using an emulator, and it's always empty. However, using all zeroes in my code leads to graphics glitches in the output.

I'm stumped. Can I get some help on this?
It's right under ...

One last thing I'm having trouble with.

There are a few routines in the code that seem to temporarily point the address of the pattern data to a location offset from a fixed address, draw a section of a tile, and then restore the original pointer. Here's an example:


LAB_07C3: ; Code $1E
;Get ...

The C2 decoder is working near perfectly now. That means SCAT can decode basically any media file from a Digital Pictures game! I'll make a new version up of SourceForge as soon as I iron out a couple of remaining bugs.

Thanks as always, TascoDLX. Actually, I stumbled upon the answer myself back in December 2014, but I didn't know about the default value for the font generator. Cheers for that!

I put a similar post up on the Sega-16 forums and ended up answering my own question. Forgot to update my post here as ...

Well, the VRAM dump you posted from Slam City is definitely byteswapped. You can tell by looking at the name table. That's the only reason I mention it. It's an old KMod bug and I'm not sure if it was ever fixed in an official release. Just something to look out for.


I'll take your word for it ...

Thank you both for replying to this thread.

@TascoDLX: You missed the post? What the hell am I paying you for? :wink:
As far as I can tell, the VRAM dump is not byteswapped. The first tiles in Corpse Killer's VRAM are a font, which is easily recognizable in a hex editor.

@r57shell: I tried gens-rr ...

Digital Pictures used a few different forms of compression in their games for the Sega CD and 32X that could be useful.

Descriptions (including some of my own ) can be found at this page on MultimediaWiki.

I've got most of the various graphics compression schemes cracked, but I'm stumped on type C2 and its derivatives. I'm sure it's compressed in some way, but I'm having trouble figuring out how the compressed data relates to the decompressed VDP data.

Below is the first frame from the Digital ...

How hard would it be to reverse engineer the graphics decoder from a Sega CD game?

I've been working on a decoder for the media files used in games from Digital Pictures (e.g. Night Trap, Sewer Shark, etc.). I've been able to figure out most of the encoding types (there are about 16 in total) using ...

I've been working on my decoder program quite a bit these days. Mostly I've been fixing little things, like adding automatic video frame rate and audio sample rate support, but I've also made some big additions. The program can now read and decode most (if not all) the videos from Prize Fighter, as ...

Still working on the program. I added support for video type $C8 (used in Sewer Shark), and I'm really close to figuring out how $C6 and its derivatives work. I also did a big rewrite to make it easier to add more types of data chunks, and added support for exporting AVI files that contain both a ...