Playback spline path based on video time

[richadam]

I have a video recording of a drive.  The spline was created using the GPS coords of the drive.  The time of the video can yield the world position of the vehicle.  I have attempted to use this to playback the drive along the curve.  This yields strange non-linear results as advancing the position through the curve is non-linear.  Some sections of the playback go much faster than others.

What is the best manner to simply get the position on the curve to set my camera for the current frame so that the playback matches velocity and position of the drive playing in the video?

[Jake]

If you set TF of a spline, resulting position isn't equal with percentage (one exception: if all segments have the same length). To get the latter, set the distance.