Greetings! A quick search did not surface an existing thread on this issue, so….
I have just begun feeding PVRTexLib (and PVRTexTool as a check) 4096×4096 textures and am seeing the following exception in both cases on Mac OS X:
“The active PVRTC compressor cannot handle MIP-levels bigger than 2048×2048”
Curiously, in the PVRTexLib case, feeding PVRTextureUtilities::CompressPVR a quality parameter of zero does *not* result in an exception. Quality issues at this level, though, had me attempting to increase the quality value—at which point the exception returns.
Our PVRTC compressor actually uses two code bases at the moment. We have a fast compressor (quality level 0) which can handle 4k by 4k textures, and our high quality compressor (all other levels) which can currently only handle 2k by 2k. We’re looking at increasing this limit currently, and larger values should be enabled for at least 64-bit builds by our next release.