The REFERENCE_TIME data type defines the units for reference times in DirectShow. Each unit of reference time is 100 nanoseconds.
typedef LONGLONG REFERENCE_TIME;
The REFERENCE_TIME data type is a 64-bit integer.
Reference times are usually measured from one of the following baselines:
- An absolute clock time. In this case, the baseline will depend on the implementation of the clock. For more information, see Reference Clocks.
- Relative to the start of playback.
For more information about reference times, see Time and Clocks in DirectShow.