Apple 7.2 manual MPEG-4 Audio Export Options

ÂFile Format: To ensure operability with devices made by ISMA members, choose “MP4 (ISMA).” For more information, go to www.isma.tv/.

ÂVideo 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.

ÂData 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 bandwidth.

ÂOptimized 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 choose.

ÂImage Size: Current maintains the source material size. To choose a size not listed in the pop-up menu, choose Custom.

ÂPreserve 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.

ÂFrame 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.

ÂKey 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 options:

ÂRestrict 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.

ÂEncoding Mode: Choose whether you want the best quality or faster encoding.

MPEG-4 Audio 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 Audio.

Chapter 4 Exporting Files with QuickTime Pro

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