grfcodec error

[jgf]

In attempting my first TTD graphics mod (simply trying to replace that hideous checkerboard terrain in toyland), I've run into a problem converting the pcx back to grf. The pcx looks fine, I changed no sizes nor added/deleted sprites, merely gave the ground tiles a consistent grassy appearance; but when trying to recompile the file I get:

Error: invalid compression, data diff at 2992 of 2996 bytes, even uncompressed, aborting.

Now what?

[Patchman]

How are you running grfcodec? What options?

[jgf]

I used the default settings as explained in the docs to generate the pcx and nfo files. I edited the former (didn't touch the latter) and used the default settings to (attempt to) recompile the grf. This was done in a dos window opened in the grfcodec directory.

[DaleStan]

default settings ... default settings

Just as "latest" is not version number, "default" is not a setting.

What, *exactly*, did you type?

[jgf]

I am not at my home computer so don't have the docs handy. By default I meant I typed exactly what the docs said to recompile the file; I used no additional switches.

[jgf]

FTR:

I typed: grfcodec -d trgt.grf

to create the pcx and:

grfcodec -e trgt.grf

to create the new grf

I got the error message; though a new grf was created it wouldn't load.

[Patchman]

Very strange... it seems that for some reason your PCX edits cause grfcodec to be unable to properly compress the sprite, even with compression turned off. I have no clue what could be causing that...