ormation apply to the field(s) or the frame(s) associated with the picture by pic_struct. The contents of the clock timestamp syntax elements indicate a time of origin, capture, or alternative ideal display. This indicated time is computed as clockTimestamp = ((hH*60+mM)*60+sS)*time_scale+ nFrames nuit_field_based_flag ) ) + tOffset, (D-1) in units of clock ticks of a clock with clock frequency equal to time scale Hz, relative to some unspecified point in time for which clockTimestamp is equal to 0. Output order and DPB output timing are not affected by the value of clockTimestamp. When two or more frames with struct equal to 0 are consecutive in output order and have equal values of clockTimestamp, the indication is that the frames represent the same content and that the last such frame in output order is the preferred representation. NOTE 7 - clockTimestamp time indications may aid display on devices with refresh rates other than those well-matched to DPB output times. clock_timestamp_flag[ i ] equal to 1 indicates that a number of clock timestamp syntax elements are present and follow immediately. clock_timestamp_flag[ i ] equal to 0 indicates that the associated clock timestamp syntax elements are not present. When NumClockTS is greater than 1 and clock_timestamp_flag[ i ] is equal to 1 for more than one value of i, the value of clockTimestamp shall be non-decreasing with increasing value of i. ct_type indicates the scan type (interlaced or progressive) of the source material as specified in Table D-2. Two fields of a coded frame may have different values of ct_type. When clockTimestamp is equal for two fields of opposite parity that are consecutive in output order, both with ct type equal to 0 (progressive) or ct_type equal to 2 (unknown), the two fields are indicated to have come from the same original progressive frame. Two consecutive fields in output order shall have different values of clockTimestamp when the value of ct_type for either field is 1 (interlaced). Table D-2 - Mapping of ct_type to source p