Timewarp speed expressions

Hello Flame people,
Is there an expression that converts speed to timing in the timewarp node, and reverse?
In old versions of flame, those two parameters were linked together, and when you moved the speed, you could see the effect on the timing curve. This might be useful when your timewarp is set on speed and you need to link to an eval expression with camera.
I also want to synchronize two similar travelling shots, using the timewarp values linked to position.tracking.x, but i lost all my mathematical abilities (speed=dx/dt …). Is there a way to link all this (first shot is reference, second shot need to be timewarped to match the speed) with expressions?
Thanks a lot

You can convert timing to speed, but not the other way around.
In the speed channel enter the expression 100*(Timing -(eval(Timing, frame -1))) or
100*(eval(Timing, frame +1)-Timing). The first bases the speed on the difference between the current frame and the previous frame. The latter does the opposite. I use this a lot when I want to see what sort of speed change I’m making when I do my timewarp by timing. I usually use the first one.


Thanks ytf, that is a good clue,
The opposite should be like an integer function but i don’t know how to translate it. it’s sad because you can see the Timing value in that box under the speed parameter, but not in the curve editor.