MPEG-4 Video Export Options
When you export a movie to MPEG-4 format (by choosing File > Export and then
choosing “Movie to MPEG-4”), you access the following options by clicking Options and
then clicking Video.
Exporting Files with QuickTime Pro
Â File Format: To ensure operability with devices made by ISMA members, choose
“MP4 (ISMA).” For more information, go to www.isma.tv/.
Â Video Format: Choose the video compressor (codec) you want to use to compress
your video. For the highest quality at the lowest data rate (or the smallest file), H.264
is recommended. If you need the file to play on a device that supports MPEG-4 video,
choose MPEG-4 Basic or MPEG-4 Improved, depending on the target device. If your
source movie’s video track is already compressed, you can choose “Pass through” so
that the video doesn’t get compressed again.
Â Data Rate: The more kilobits per second (kbps), the better the movie quality. For
best playback, however, don’t choose a data rate higher than the available
Â Optimized for: If you choose H.264 from the Video Format pop-up menu, choose
your intended delivery method from the “Optimized for” pop-up menu. This setting
tells the codec how much the data rate can vary above and below the data rate you
Â Image Size: Current maintains the source material size. To choose a size not listed in
the pop-up menu, choose Custom.
Â Preserve Aspect Ratio Using: If you are changing the image size, use this option to
specify an option in case the movie needs to be scaled to the new dimensions.
Letterbox will scale the source proportionally to fit into the clean aperture, adding
black bars to the top and bottom or sides as necessary. Crop centers, scales, and
trims to the clean aperture. Fit Within Dimensions adjusts to the destination size by
fitting to the longest side, scaling if necessary.
Â Frame Rate: In most cases, your video will look better if you choose a number that is
exactly divisible by the FPS (frames per second) of your source. For example, if your
source is captured at 30 FPS, choose a frame rate of 10 or 15. Don’t choose a rate
larger than that of your source material.
Â Key Frame: The more often you specify a key frame (the lower the number), the
better the video quality, but the bigger the file.
If you choose MP4 from the File Format pop-up menu and H.264 from the Video
Format pop-up menu, and then click Video Options, you get the following additional
Â Restrict Profile(s) to: If you need the file to play on a device that conforms to one or
more of the standard’s profiles, check those profiles here.
Â Encoding Mode: Choose whether you want the best quality or faster encoding.