private float getFrameDurationNs() {
    if (composition == null) {
      return Float.MAX_VALUE;
    }
    return Utils.SECOND_IN_NANOS / composition.getFrameRate() / Math.abs(speed);
  }
Returns the current value of the currently playing animation taking into
account direction, min and max frames.
lottie/src/main/java/com/airbnb/lottie/utils/LottieValueAnimator.java