I store the inverse frequency of each note, and its length in 1/32 notes. I didn't do it by hand, however. I rearranged a MIDI of the song in LMMS, and wrote a Python program to read all the notes and convert them to this format.They also mentioned a "transcoder" for the video but I'm not sure it if was in that same thread. Looks like a good part of it was automated.