Timing in demos

In my previous post, I talked about aligning visuals and music by introducing "delay/speed-up taps" for DeltaT.

It was suggested that an even better solution would be to make all effects as functions of an input value f going from 0 to 1 and then scaling that accordingly. This is actually similar to what I am proposing. But whether it works or not depends on the granularity (and number) of your effects.

A "part" is a long segment (1 minute+) that consists of very many effects. I find it much easier to tune the timing of a part than of the many effects within the part. What I do now is this:

Record the demo as an .avi, then play it back (with the music) inside my engine. This is much faster to load and "scratch" (forwards/backwards). The delay/speed-up taps can then be added and their exact timing copied as is into the original real-time demo.