The "handshake" is type 9 RTMPE handshake
The handshake is used with RTMPE streams. rtmpdump cannot handle sites that require a type 9 handshake, until someone makes a patch for it.
get-flash-videos relies on rtmpdump for RTMP streams, hence if rtmpdump does not work, then get-flash-videos is definitely not going to work.
the file you are referring to (handshake.h) is a source file. for it to be of use it has to be compiled into the rtmpdump program. i have instructions for windows here
http://svnpenn.blogspot.com/2011/03/rtmpdump.html
Finally, You have shown that you do not know about
:
1. get-flash-videos
2. source code
3. compiling programs
4. programming in general
a more appropriate thread title would be "What I know so far" or "Hey guys how do I download from ITV"