The problem is re-compressing AE cam files. The only real workaround is to use a DLL proxy with custom code to work around the issue which is an extremely dodgy hack that will likely only work with certain versions of the game.
So it would intercept the function that does the cam loading and check if its an AO cam and then manually copy into the psx emu vram.. which is a lot harder than it sounds
Edit: Btw NovaMan that isn't a cam header, the cam header is just another file chunk which looks like this:
Chunk size - 4 bytes
Ref count - 4 bytes
Type - 4 bytes (Bits, Anim, Palt .. whatever else)
Resource Id - 4 bytes