Adobe PREMIERE 5 User Manual page 345

Premiere must repeat every fourth frame in the clip to match the number of frames required
to match the timebase. If a clip shot at 30 fps is used in a project with the timebase set to 24, the
mathematics work in reverse, and every fourth frame cannot be displayed.
When the timebase doesn't match the Video Settings (Timeline playback) frame rate or the
•
Export Settings frame rate, Premiere uses the Video Settings or Export settings frame rate to
determine which frames can be included in Timeline playback and export, respectively. For
example, if the original clips and timebase are 30 fps, but you set the Video Settings frame rate
to 15 fps, you will see only every other frame in the Timeline when you preview.
Premiere lets you alter the relationship between source clip frame rate, timebase, and playback
and export frame rates through the following options:
The File > Interpret Footage command alters the frame rate of a source clip and changes its
•
duration. You specify a frame rate and Premiere redistributes all of the clip's frames over a
longer or shorter period of time as necessary. For example, if a one-second clip was originally
captured at 30 frames per second, and you use Interpret Footage to apply a frame rate of 15
frames per second, the clip becomes two seconds long. Premiere takes the resulting source
frame rate and compares it to the timebase to calculate which of the clip's frames can be
included in the Timeline.
The Clip > Video > Frame Hold command alters the frame rate of a source clip without
•
changing the speed of the action in the clip. The frame rate you specify is created from the
frames that remain after Premiere has compared original source frames against the timebase.
For example, if thirty of a clip's frames display per second in the Timeline, and you use Frame
Hold to apply a frame rate of 15 frames per second, Premiere will omit every other frame of
that clip from playback and export.
The Clip > Speed command increases or decreases the frame rate of a clip in the Timeline,
•
but unlike Interpret Footage, the change is specified as a length of time or as a percentage of the
original duration. If the resulting frame rate is higher than the program frame rate specified in
Video Settings or Export Settings, Premiere must omit frames that end up between Timeline
frames as determined by the Timebase and the playback or export frame rate. If the resulting
frame rate is lower than the playback or export frame rate, Premiere must repeat frames to
match the playback or export frame rate.
ADOBE PREMIERE 5.0 337
User Guide