cause they precede, in decoding order, an IDR picture withno_output_of_prior_pics_flag equal to 1 or inferred to be equal to 1, the output times derived from dpb_output_delay shall be increasing with increasing value of PicOrderCnt( ) relative to all pictures within the same coded video sequence subsequent to any picture having a memory_management_control_operation equal to 5. pic_struct indicates whether a picture should be displayed as a frame or one or more fields, according to Table D-1. Frame doubling (pic_struct equal to 7) indicates that the frame should be displayed two times consecutively, and frame tripling (pic_struct equal to 8) indicates that the frame should be displayed three times consecutively. NOTE 5 - Frame doubling can facilitate the display, for example, of 25p video on a 50p display and 29.97p video on a 59.94p display. Using frame doubling and frame tripling in combination on every other frame can facilitate the display of 23.98p video on a 59.94p display. When pic_struct is present (pic_struct_present_flag is equal to 1), the constraints specified in the third column of Table D-1 shall be obeyed. NOTE 6 - When pic_struct present_flag is equal to 0, then in many cases default values may be inferred. In the absence of other indications of the intended display type of a picture, the decoder should infer the value of pic_struct as follows: - If field_pic_flag is equal to 1, pic_struct should be inferred to be equal to (1 + bottom_field_flag). Otherwise, f TopFieldOrderCnt is equal to BottomFieldOrderCnt, pic_struct should be inferred to be equal to 0. - Otherwise, if TopFieldOrderCnt is less than BottomFieldOrderCnt, pic_struct should be inferred to be equal to 3. - Otherwise (field_pic_flag is equal to 0 and TopFieldOrderCnt is greater than BottomFieldOrderCnt), pic_struct should be inferred to be equal to 4. bic_struct is only a hint as to how the decoded video should be displayed on an assumed display type (e.g., interlaced or progressive) at an assumed display rate. When another display ty