Using the Retiming Controls
The retiming controls have two common uses.
• Converting video from one frame rate to another: This typically involves converting NTSC
to PAL frame rates or PAL to NTSC frame rates. This function uses only the setting of
the Rate Conversion pop-up menu and is automatically configured when necessary.
• Converting video to a new speed: This can be a matter of playing the existing frames at
a different rate or, in the case of slow-motion effects, it can require generating
In all cases, if the source media file contains audio, the audio also has its speed changed,
with the audio pitch corrected so that it sounds the same as the original, just at a different
speed. This ensures that you will maintain sync between the video and audio.
If you preview a setting that uses retiming controls, the video will play at its new frame
rate or speed, but it will not have been processed by Frame Controls and will be of a
lower quality than the actual transcoded output file will be. The audio is pitch corrected
when the setting is previewed.
Working with Frame Controls
If you are using retiming controls on a setting using the QuickTime Movie
output format and choose “Pass-through” for the audio setting, the audio does not have
its speed changed and will not maintain sync with the video. See
About the QuickTime
Movie Encoder Pane
for more information.