Figured out LibTheoraPlayer is a completelly diferent thing to libTheora so installed the right one.
But now I get:
make
[ 50%] Building CXX object CMakeFiles/SFMLTheora.dir/src/SFMLTheora/Video.cpp.o
/home/richy/libs/SFMLTheora-CMake/src/SFMLTheora/Video.cpp: In constructor ‘SFMLTheora::MemoryLoader::MemoryLoader(const string&, const void*, long unsigned int)’:
/home/richy/libs/SFMLTheora-CMake/src/SFMLTheora/Video.cpp:53:24: error: ‘memset’ was not declared in this scope
/home/richy/libs/SFMLTheora-CMake/src/SFMLTheora/Video.cpp:54:27: error: ‘memcpy’ was not declared in this scope
/home/richy/libs/SFMLTheora-CMake/src/SFMLTheora/Video.cpp: In member function ‘void SFMLTheora::MemoryLoader::Set(const string&, const void*, long unsigned int)’:
/home/richy/libs/SFMLTheora-CMake/src/SFMLTheora/Video.cpp:86:24: error: ‘memset’ was not declared in this scope
/home/richy/libs/SFMLTheora-CMake/src/SFMLTheora/Video.cpp:87:27: error: ‘memcpy’ was not declared in this scope
/home/richy/libs/SFMLTheora-CMake/src/SFMLTheora/Video.cpp: In member function ‘virtual int SFMLTheora::MemoryLoader::read(void*, int)’:
/home/richy/libs/SFMLTheora-CMake/src/SFMLTheora/Video.cpp:98:59: error: ‘memcpy’ was not declared in this scope
make[2]: *** [CMakeFiles/SFMLTheora.dir/src/SFMLTheora/Video.cpp.o] Error 1
make[1]: *** [CMakeFiles/SFMLTheora.dir/all] Error 2
make: *** [all] Error 2