Mixing Frame Rates
Clips with any Final Cut Pro–supported frame rate can be added to a sequence and
played back in real time. Depending on whether the clip frame rate is faster or slower
than that of the sequence, Final Cut Pro skips or repeats frames of the sequence clip.
Nonmatching frame rates are handled three ways.
If a clip and sequence have matching frame rates:
Each frame of the clip’s media file is played back in the sequence. No frame rate
conversion occurs, even when the clip and sequence codecs don’t match. Ideally, your
clip and sequence frame rates should always match.
If a clip’s frame rate is slower than the sequence frame rate:
Final Cut Pro repeats frames of the clip’s media file as necessary to create the
appearance of playback at the sequence frame rate. The repeating pattern is not
necessarily compatible with standard pull-down or frame duplication patterns of other
formats. In cases with interlaced footage (such as a PAL clip within an NTSC sequence),
fields are sometimes doubled (instead of frames) to avoid field stuttering.
If a clip’s media file frame rate is faster than the sequence frame rate:
Final Cut Pro drops frames of the clip’s media file as necessary to create the appearance
of playback at the sequence frame rate. Because frames are skipped, you won’t always
be able to trim these clips with frame accuracy. In those cases, you may want to open
the original clip in the Viewer to set a specific In or Out point before editing the clip
into the sequence.