resolveFps method
The effective frames per second for a composition whose own frame rate is
compositionFrameRate, or null when every display frame should be
rendered (max, or no usable rate).
Implementation
double? resolveFps(double? compositionFrameRate) {
if (this == max) return null;
var fps = this == composition ? compositionFrameRate : framesPerSecond;
if (fps == null || !fps.isFinite || fps <= 0) return null;
return fps;
}