-media command line key

[NickDoom]

I've found -media key useful for launching crossovers such as this one.
It should work as -file key, but:
1) Only media (sprites, sounds, music etc) is loaded. Everything else should be ignored.
2) Quite the opposite the "-file", priority of those .raw resources are lower than IWAD resources, not higher. So if we have multiple resources with the same name, the one from the PWAD has the top priority as usual, the one from IWAD is loaded if there are no PWAD ones, and -media provides only resources which can't be found in neither IWAD nor PWADs.
3) Palette (if any) is not ignored completely, but affects the WAD data only (does not override the existing one). So everything from the "-media BigFile.WAD" is loaded as if it was extracted into .pk7 as .PNGs, with the palette from BigFile.WAD. Since palette conversion of BigFile.pk7\*.png works well now, there will probably no problem supporting such conversion — just load those graphics as if they are .PNGs with the .WAD palette, but don't load the palette itself, keep the existing one.
It looks easy to implement and changes nothing unless the new "-media" key is used, so there will be no compatibility issues unless some bugs crawl into the actual implementation.

[NickDoom]

Also, a tiny technical aspect: don't bother remembering the whole -media files list, or even the origin of each .raw resource (lol). Just process files (and -file / -media keys) from left to right, as usual. But -file .WADs always override existing .RAW resources, and -media .WADs never override them. Yes, that means the priority of -file PWADs increases from left to right (as usual AFAIK), and the priority of -media PWADs decreases from left to right. It looks intuitive enough for me.