Error when compiling OpenNI2 driver from source

[chhf129]

When I do "make" command, I have the following error, any idea?
libfreenect/OpenNI2-FreenectDriver/src/VideoStream.hpp:56:40:
error: unexpected type name 'int64_t': expected expression
uint64_t temp_delta = std::abs<int64_t>(timestamp - prev_int);