+#ifndef _TIMEBASE_H
+#define _TIMEBASE_H 1
+
+// Common timebase that allows us to represent one frame exactly in all the
+// relevant frame rates:
+//
+// Timebase: 1/60000
+// Frame at 50fps: 1200/60000
+// Frame at 60fps: 1000/60000
+// Frame at 59.94fps: 1001/60000
+//
+// If we also wanted to represent one sample at 48000 Hz, we'd need
+// to go to 300000. Also supporting one sample at 44100 Hz would mean
+// going to 44100000; probably a bit excessive.
+#define TIMEBASE 60000
+
+#endif // !defined(_TIMEBASE_H)