4.2

A key frame is a frame that stores a complete
image. Key frames provide the entire image in
the video stream; after that image is provided,
incremental changes between related frames
are stored (not the entire image). Thus, when
the image in the video changes dramatically—
for example, when switching between images
—a keyframe must be created to mark the
location of change. It’s recommended that you
allow Compressor to determine the key frame
interval for your output file; however, you can
also set the key frame interval manually.
Note: More key frames make the output video
easier to move through (scrub) during
playback. Fewer key frames make the
key frame interval