Apple Final Cut Pro HD (4.5): New Features - Manual (Page 124)

124 Appendix High Definition Video Fundamentals
Recording and Playing Back Variable Frame Rates
With DVCPRO HD
Some DVCPRO HD devices allow recording and playback of variable frame rates from
4 to 60 frames per second. Variable frame rate recording and playback are limited to
the 720p HD format. The camera CCD outputs from 4 to 60 fps (in whole number
increments), but the built-in VTR records at a constant rate of 60 fps (or 59.94 fps).
Duplicate frames in the 60 fps video stream are tagged to be removed later by special
frame rate converter playback units.
For example, if the camera is set to record 15 fps, 3 out of every 4 frames are tagged as
duplicate and ignored when played back on the frame rate converter. Another useful
feature of a frame rate converter is that it can output at different frame rates as well, so
you can record at 60 fps but output your video at 24 fps with a 3:2 pull-down. Some
frame rate converters can also do upconverting and downconverting, allowing you to
shoot 720p24f variable frame rate footage and output fast- and slow-motion footage to
1080i24p or 480i (standard definition) with a letterboxed 3:2 pull-down.
UP01022.Book Page 124 Tuesday, March 23, 2004 7:32 PM