Expression(hold opacity connected to audio keyframes)
by Michael Stark (mikeguy3086)
on
Jun 18, 2008 at 3:09:39 pm
So what I'm trying to do with no luck is this. Let's say we have two layers of footage, and one audio layer - making it a total of 3 Layers.
What I want to do is have the top most layer fluctuate it's opacity according to the audio keyframes. I'm not really sure about audio keyframes but I'm sure I could figure it out. My problem also is that I don't want the opacity to be any percentage but 0% or 100%. Aka a strobe effect according to sound.
Just to paint a picture, I have one layer of moving 3d text, and on top of that is the exact same footage, but rendered with a glow.
Any help would be much appreciated because I'm new to expressions and this is a tad bit advanced for me.
Re: Expression(hold opacity connected to audio keyframes) by Kevin Camp on Jun 18, 2008 at 5:16:30 pm
something like this may work:
min = 0; //set minimum audio level
max = 15; //set maximum audio level
a = thisComp.layer("Audio Amplitude").effect("Both Channels")("Slider");
Math.round(linear(a,min,max,0,1)) * 100
'a' is the audio amplitude parameter for your audio layer. set 'min' and 'max' as needed for your audio levels... the layer will be 100% opacity when audio levels are above the midpoint of the audio range, and it will be 0% when levels are bellow that point....
