Time Code Sample Data

QuickTime Movie File Format Specification, May 1996

Time Code Sample Data

There are two different sample data formats used by time code media.

If the Counter flag is set to 1 in the time code sample description, the sample data is a counter value. Each sample contains a 32-bit integer counter value.

If the Counter flag is set to 0 in the time code sample description, the sample data format is a time code record, as follows.

Hours: An 8-bit unsigned integer that indicates the starting number of hours.
Negative: A 1-bit value indicating the time's sign. If the bit is set to 1, the time code record value is negative.
Minutes: A 7-bit integer that contains the starting number of minutes.
Seconds: An 8-bit unsigned integer indicating the starting number of seconds.
Frames: An 8-bit unsigned integer that specifies the starting number of frames. This field's value cannot exceed the value of the Number of frames field in the time code sample description.