To convert your old pcx (Original Falcon and AF) tiles into DDS format what RV and OF uses, there is few options. You can do everything manually by using utility like IrFanview or super manually by PhotoShop and save tile by tile (but I dont know anyone who would do it this way), or you can use the automated method with an extra utility.

This automated method is by using utils called SeasonSwitcher found in the various RV and OF installation packages.

When you run this util, it reads the Falcon 4 registry for curTheater directory, it then proceeds to find \terrdata\textures\ directory and starts to process the texture.zip and texture.bin found in this directory.

Usage:

SeasonSwitcher.exe -0

To run it automatically from command line.

The util then reads the texture.zip and creates new DDS files for each of the pcx found in the texture.bin, it also creates the completely new fartiles system.

Note!
If your texture.bin contains “holes” so that you are missing ANY tiles at the texture.zip, this util will fail to create the tiles, it just gives you an error and exits. This is major downside of the util if you happen to have such “holes” in the texture.zip - a fact known to happen in my theaters tile-sets sometimes.

Also if your registry is not set for proper theater you want to process, the util runs the current theater (what ever that might happen to be).

There is also util called TerrainTexCompress but I dont know what is the difference regarding SeasonSwitcher, most likely they perform pretty much the same operations to the tiles.