I'm looking for some guidance with respect to compressing data using RNC ProPackED (http://www.romhacking.net/utilities/1310/
), specifically when reinserting files back into a PSX image.
I'm currently trying to see what's under the hood of NBA Jam T.E.
I've used CDMage to view and export data files, and I've been able to de
compress certain .BIN, .RNC, .GFX, and .COL files within that image using commands in a .bat file that executes RNC ProPackED.
I use the following command in a .bat to reinsert decompressed images:
rnc_lib p decompressed.bin compressed.bin -m=2
The headers in the orginial files indicate Mode 2 RNC compression is used. Upon executing the command, I then take the contents of the .bin file and -- using HxD -- I overwrite the header and image data in the original compressed file at the proper address. I then import the file into the PSX image via CDMage and run the game in ePSXe.
I'm currently just looking at splash screens in the HICOL.GFX file. When the game boots up to the Acclaim screen, which is the image I'm messing around with, I get 1 of 2 results:
- 1) A very garbled version of my image (rare) or
- 2) A clip of the Iguana screen (instead of my image) with garbled pixels at the top (most common result).
I can see my image perfectly in the decompressed .bin that I've modified; the image appears as a 40x25 tile graphic using a 15bpp RGB codec and 2-dimensional mode in Tile Molestor. If I attempt to decompress the file that I had used RNC to compress, it gives me an error. I can also say that the inserted compressed image appears to be a few KB less than the original compressed image that I am trying to replace.
I did a Google search for instructions and found those for the RNC 2.14/2.08 version (like on the Aminet site). That application, however, seems to have more robust parameters that can be used, and those parameters don't seem to be working with ProPackED. RNC 2.14/2.08 is also too old to run on my comp at current.
Does anyone use RNC ProPackED? Any advice on how I should be structured the pack/compress command, or what I otherwise might have missed?
Quick update: I decided to skip a step and used HxD to insert the recompressed image directly into Track1.bin. The result is the exact same. I also tried to decompress, edit and recompress another image, this time the title screen. Again the result is a different screen being pulled, plus garbled pixels at the top.
In each case, despite overwriting the correct section in the game that has the screen I'm trying to change, the game loads the screen that is compressed just prior to it.
Example 1: The location for the Iguana screen is at $1AC9A in HICOL.GFX (the RNC header begins here), just before the Acclaim screen (its header is at $2867F). When I try to replace the Acclaim screen, a messed up version of the Iguana screen displays in its place. When it is time to load, the Iguana screen displays correctly, so I know I've replaced the correct section of code and have impacted nothing else.
Example 2: The location for the loading screen is at $0 in HICOL.GFX, just before the title screen's header at $E9C2. When I try to replace the title screen, a messed up version of the loading screen displays in its place. When it is time to load, the loading screen displays correctly, so I know I've replaced the correct section of code and have impacted nothing else.