C++ Expert with YUV pixel format knowledge

I'm looking for an expert C/C++ developer who can help us to write a small highly performant function to convert an image frame from YCbCr into NV21. The current function code converts it to YUV422, which is not suitable for our use case. Thus part of the processing should or can be reused so it is really the frame conversion into the right output format we are looking for (uvc_frame_t). Requirements: - very good knowledge of YUV pixel formats and conversions - expert knowledge of C/C++ - desirable to have knowledge on libuvc / libjpeg