counting bars and notes with expressions from a known bpm

[Tomas Bumbulevičius]

Hey Sam, what might be the possibilities, that this execution uses external data, with all notions of params?

Find out more:
After Effects Tutorials: motion design, expressions, scripting.
Boxer – Dynamic Text Boxes Template with a Live Preview

[Alex Printz]

place this onto a null property that you want to animate (I usually use it to generate a Tone); you will need two sliders, one for the beats per minute, and one for the number of beats in a measure.

Note that if your framerate doesn’t work well with the BPM you’ve chosen, it might get messy and/or bleed between frames.

There are 3 outputs possible; Z (off), Y (minor beat), and X (major beat); set them to whatever you want and/or manipulate the code.

s = effect("BPM Slider")(1);
m = effect("Number of beats per measure")(1);

X = value;
Y = value/5;
Z = 0;

b = 60/s; //convert to seconds
d = thisComp.frameDuration;
t = time-inPoint; //current time

e = (d+(s/2000)); //slop for error

function p(x){ //previous frame value
return thisProperty.valueAtTime(Math.ceil(time-framesToTime(x))) };

if( (t/b) %1 <e && p(1) != 0) //if current frame for beat
((t/(b*m)) %1 <e && p(1/s) != 0) ? X : Y; //if major or minor beat
else Z; //else off

Alex Printz
Mograph Designer