Author Topic: Possibility of a Method to Edit Amiga Lemmings? (Read 6446 times)

Dullstar · « **on:** July 10, 2009, 08:10:51 AM »

Might a level editor be made for the Amiga lemmings or at least something that can be used to put levels back into the game (unless of course I'm just trying to use the wrong files and don't realize it)?

ccexplore · « **Reply #1 on:** July 10, 2009, 07:38:41 PM »

Your best bet right now is to just use Lemmix, and then see if your emulator has ability to do file transfers between files on your PC and the files in the simulated Amiga disks.

Dullstar · « **Reply #2 on:** July 11, 2009, 01:37:42 AM »

I imagine there wouldn't be a difference between the hard drive version and the disk version level storage method? Or am I mistaken?

Probably should of noted that I have the hard drive version. At least, I'm pretty sure, considering I don't load floppy disk images on WinUAE

EDIT: Poorly worded. I do load disk images for most games, but Lemmings isn't one of them. Of course, considering I currently only have three games...

ccexplore · « **Reply #3 on:** July 11, 2009, 01:53:38 AM »

The hard disk version is good. I'm not even sure if the floppy version you can easily transfer files to/from it, since the floppy might use a custom format. (It's a custom floppy formating that doomed Mike from using his official Amiga level editor from his old disc, for example.)

Anyway, I haven't tried any of this myself, so take my suggestion with a grain of salt.

Dullstar · « **Reply #4 on:** July 11, 2009, 06:13:50 AM »

The problem is, none of the files have file extensions, so I can't be sure if they're even compatible with DOS lemmings in any way whatsoever.

However, like I said, it *might* be possible for him to read it in an Amiga or an emulator (though maybe not)

Mr. K · « **Reply #5 on:** July 11, 2009, 06:04:58 PM »

Extensions mean nothing. I could rename an MP3 to .bmp and it would still be an MP3.

Just pull some of the files out and try loading them with Lemmix. Maybe something good will happen.

Dullstar · « **Reply #6 on:** July 11, 2009, 09:19:31 PM »

Yeah, suppose I could have tried a different file. Or maybe notepad could be used to compare and see which one looks as much like a file in Lemmix. I may have opened the wrong file in Lemmix, I suppose. Could try a different file.

Dullstar · « **Reply #7 on:** October 04, 2009, 03:39:11 PM »

Didn't we have someone who extracted the levels from the Amiga version?

Mindless · « **Reply #8 on:** October 07, 2009, 06:14:16 PM »

Quote from: Dullstar on 2009-10-04 09:39:11

Didn't we have someone who extracted the levels from the Amiga version?

Yes, I did; they're here.

Quote from: Dullstar on 2009-07-10 02:10:51

Might a level editor be made for the Amiga lemmings or at least something that can be used to put levels back into the game (unless of course I'm just trying to use the wrong files and don't realize it)?

You'd have to reverse-engineer the compression format used on the Amiga levels. There's only a decompressor available, no compressor.

ccexplore · « **Reply #9 on:** October 07, 2009, 08:41:18 PM »

Quote from: Mindless on 2009-10-07 12:14:16

Quote from: Dullstar on 2009-07-10 02:10:51
Might a level editor be made for the Amiga lemmings or at least something that can be used to put levels back into the game (unless of course I'm just trying to use the wrong files and don't realize it)?

You'd have to reverse-engineer the compression format used on the Amiga levels. There's only a decompressor available, no compressor.

But you don't need to compress it exactly the way the official game does, as long as the compressor's output is compatible with the decompression used in the game.

Also, I thought they use the exact same compression formats in Amiga?

Dullstar · « **Reply #10 on:** October 08, 2009, 03:03:07 AM »

I guess I'll have to write my own editor, at this rate.

Mindless · « **Reply #11 on:** October 08, 2009, 05:37:53 AM »

Quote from: ccexplore on 2009-10-07 14:41:18

Quote from: Mindless on 2009-10-07 12:14:16
Quote from: Dullstar on 2009-07-10 02:10:51
Might a level editor be made for the Amiga lemmings or at least something that can be used to put levels back into the game (unless of course I'm just trying to use the wrong files and don't realize it)?

You'd have to reverse-engineer the compression format used on the Amiga levels. There's only a decompressor available, no compressor.

But you don't need to compress it exactly the way the official game does, as long as the compressor's output is compatible with the decompression used in the game. Also, I thought they use the exact same compression formats in Amiga?

I'm pretty sure they don't... here's an Amiga Lemmings hard-disk install if you wish to try it yourself.

ccexplore · « **Reply #12 on:** October 08, 2009, 07:20:05 AM »

So Mindless, how exactly did you extract the levels from the Amiga version? It's not like the game comes with an accompanying decompressor program, does it? Did someone actually write a Amiga-specific decompression program or something?

I haven't used WinUAE in a while but when I have a chance, I'll definitely take a look and see. It seems pretty unlikely to me though that they would invent two separate compression formats, one for DOS and another for Amiga.

Dullstar · « **Reply #13 on:** October 09, 2009, 03:58:35 AM »

Well, someone with expertise could try and figure it out...
ccexplore? After all, look at all you did.

Mindless · « **Reply #14 on:** October 09, 2009, 06:46:20 AM »

Quote from: ccexplore on 2009-10-08 01:20:05

So Mindless, how exactly did you extract the levels from the Amiga version? It's not like the game comes with an accompanying decompressor program, does it? Did someone actually write a Amiga-specific decompression program or something?

I just asked around. And it ended up that XFD could "decrunch" them. But, AFAIK, has no "crunch" feature.

The links in that thread seem to be dead, so I'll attempt to assist you in finding XFD.

spud · « **Reply #15 on:** December 20, 2009, 02:10:33 PM »

Try this in your LemmingsHD install.

The levels you want are Tricky 01, Taxing 15, Tricky 14 and Tricky 20. They are a random selection from Van Clan Lemmings.

Here's a teaser:

Dullstar · « **Reply #16 on:** December 20, 2009, 06:34:49 PM »

Woah, did you actually get that to work? How'd you do it?

spud · « **Reply #17 on:** December 22, 2009, 10:03:08 AM »

It involved running the uncompressed level pack through ByteKiller and then a bit of messing about with the file header and footer, but yes it seems to work!

If anyone wants I could write a brief howto, so other people can try it out for themselves.

Dullstar · « **Reply #18 on:** December 23, 2009, 07:21:59 AM »

That would definitely be quite nice, since the Amiga version was quite a great version.

geoo · « **Reply #19 on:** December 25, 2009, 11:12:21 PM »

Ah, so you found a way to re-compress the data. This was the previously unsolved problem.

When Steve and I started with 2P Lemmings on the Amiga over Network through Kaillera, we got interested in whether it'd be possible to insert one's own levels, and I even started briefly to try figuring the compression format. But the interest subsided when we were told about and tried L++ for multiplayer.

Nice work nonetheless! How did you find the ByteKiller EOF compressor, and which version of this compression it is?

spud · « **Reply #20 on:** December 28, 2009, 01:04:25 PM »

Actually it was a coincidence that I started looking at this at all - I was originally digging around in the Amiga version of Lemmings to try to extract the sounds because several of the Windows ones sound sped up in comparison. After I stumbled upon this thread it intrigued me enough to have a look into the compression of the levels.

Anyway, what gave me the clue to the compression format was the documentation for XFD which stated that it could decompress ByteKiller compressed files that had had their headers modified or moved to the end of the files. I messed around with the Level000 file from the Lemmings hard drive installation provided by Mindless, first decompressing it with XFD and then attempting to recompress it and end up with exactly the same file I started with. After some time playing around with it I managed to figure out the required method to do this. I then just applied the same technique to a custom, uncompressed level pack (saved in .lvl format in Lemmix), plugged it into the Lemmings installation and, hey presto, it worked.

Stand by for a full description of how to compress the levels.