Hi,
the PVRTC source code is not open source/public.
There is a public whitepaper available about it: http://cdn.imgtec.com/sdk-documentation/PVR+Texture+Compression.Whitepaper.pdf
Otherwise you can just use the PVRTexTool (gui or command line) from the PVR SDK: https://www.imgcommunity.local/developers/powervr/installers/
bests,
Marton Tamas
