Is it possible to connect expression to multiple keyframe layers ?

[Dominik L]

Hello, I'm trying to create audio visualiser video using Soundkeys and Twixtor plugins. Ive separated kick and snare drums of my tune to 2 keyframe outputs. Now I want to use both of these outputs to control video speed using Twixtor. Is there any way to do it ? Or somehow combine 2 keyframe outputs to 1? 

Thanks

[Martin_Ritter · Accepted solution]

We need a bit more information.

How do you want to combine them?

I don't know Twixtor, but a keyframe is just a value and a property with keyframes is just a set of values.

You can say:

stream1 = keyframes of kick;

stream2 = keyframes of drums;

output = stream1 + stream2;

So whatever you are driving with this, it will happen on both, kick and drum with the intensity of those, and whenever kick and drum happens at the same frame, the intensity will be higher.

You can add (and animate) percentages and mix both as a DJ does with two turntables.

*Martin

[Dominik L]

You actually solved my problem. I was trying to do it in a very complicated (dumb) way :D. Output 1 + Output 2 did the trick. Thank you very much. Have a nice day 🙂

[Rick Gerard]

Controlling time can get tricky. You can go forward and backward in time by simply using the linear(t, tMin, tMax, value1, value2) expression where t = the value of the slider generated by the Keyframe Assistant Audio to Keyframes tool, tMin is the minimum value of the slider you want to use to start time moving forward and tMax is the maximum value you want to use for the maximum time of the clip. if you have a 10-second clip that you want to vary the speed then value1 is 0 (zero) and value 2 is 10. That will show you the first frame of the video when the slider value is at the minimum value you set and the last frame of the video when the slider value is at its maximum value. These minimum and maximum values are easy to find if you look at the Graph Editor and check the Value Graph.

If you want to look at some expression solutions that are more sophisticated than that check out http://motionscript.com and look at the great info that Dan Ebberts has posted on audio driving animation. The bottom section of Speed and frequency control will be helpful, and the first section of the Expressioner's Design Guide also has some good stuff.

If you want to use Twixtor instead of Time Remapping you should be able to figure out what values to edit. 

One more hint, when using Twixtor it is always more efficient to apply Twixtor to a solid and then point to the video you want to manipulate. You'll find it much easier to handle if you work that way.

[Dominik L]

Thank you very much! Ill definitely have a look. Have a nice day.