What is the algorithm for generating temporary map data (VTS_TMAP) for a DVD IFO file?

I want to create IFO file for VOB so that I can create DVD video.

I have specs for the contents of the VTS_01_1.IFO file, however I'm not sure how to generate the temporary map data for the VTS_TMAP section.

I think the recordings are based on frame rates, but this is not obvious from the DVD example I was looking at.

Any help or pointers to the relevant source is greatly appreciated.