humble-video-noarch/src/main/java/io/humble/video/Global.java
public static Rational getDefaultTimeBase() {
    long cPtr = VideoJNI.Global_getDefaultTimeBase();
    return (cPtr == 0) ? null : new Rational(cPtr, false);
  }
public static Rational getDefaultTimeBase() {
    long cPtr = VideoJNI.Global_getDefaultTimeBase();
    return (cPtr == 0) ? null : new Rational(cPtr, false);
  }
The default timebase used by media if not otherwise specified.