Finally: a standard format for speedramps
A framecurve is a type of animation curve that represents a variable-speed timewarp. That is, a timewarp where footage accelerates and slows down. It's called a frame curve because instead of operating with changing speed values it operates in absolute frame correlations - it gives you a table of relationships from the frame in your scene to a frame in your animation or video.
A taster (with visuals!)
Here's a small demo how some framecurves would look in your animation channels editor. If you ever dabbled with timewarps in your application your time curves looked something like that as well. On the X axis is the at_frame (your timebar). On the Y axis - use_frame_of_source the frames you are sampling from the original animation or video stream. If you ever used a retiming plugin you probably recognize that.
Makes sense? Before you ask, for framecurves we explicitly never use spline interpolations, even though they would give a smoother curve - that because every animation package interpolates curves differently and we cannot reverse-engineer every possible channel editor in existence today.
What we offer
A concrete, documented, machine- and human-readable format for outputting a framecurve, and a set of scripts for today's most popular animation and compositing packages for applying that curve to animation data.
It looks like this:
# http://framecurve.org/specification-v1
# at_frame use_frame_of_source
1 1.00000
25 25.00000
50 70.54323
125 125.00000
Store that to a file and use any of our scripts to apply it to your objects.
Contacting the authors
Framecurve is a grassroots effort and does not belong to a specific vendor. If you have any questions, comments or suggestions with regards to framecurve, do not hesitate to