User Guide

46 Chapter 2 Working With DVCPRO HD
Working With Variable Frame Rate DVCPRO HD Footage
Some DVCPRO HD devices allow recording and playback of variable frame rates from
4 to 60 fps. Variable frame rate recording and playback are limited to the 720p
DVCPRO HD format; this feature is not available with 1080i DVCPRO HD. 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 or 59.94 fps (for NTSC compatibility). Any redundant
frames in the 60 or 59.94 fps video stream are tagged to be removed later by a special
frame rate converter.
For example, if the camera is set to record 15 fps, 3 out of every 4 frames are tagged as
duplicates and ignored when played back on the frame rate converter. Once duplicate
frames are removed, the frame rate converter can play the remaining frames at one of
several standard frame rates: 60, 59.94, 30, 29.97, 24, or 23.98 fps.
Note: Some frame rate converters can also do upconverting and downconverting,
allowing you to use 720p for variable speed cinematography and then transfer to
1080i or 480i (standard definition).
Several examples of how variable frame rates are recorded on 720p DVCPRO HD
devices are shown below.
Note: Although whole-number frame rates are shown below, Final Cut Pro only
supports DVCPRO HD capture and output of NTSC-compatible frame rates, such as
59.94, 29.97, and 23.98 fps, via FireWire.