Choosing an Aspect Ratio
The aspect ratio is the ratio of the width of the visible area of the video frame to the height
of the visible area. Standard NTSC and PAL monitors have a picture aspect ratio of 4:3 (or
1.33, which is the width divided by the height). Some High Definition Television (HDTV)
formats have a picture aspect ratio of 16:9, or 1.78.
The DVD specification supports both 4:3 and 16:9 sources, but it does not support HD
video. Most HD video formats use a combination of features to create the high definition
image, including a much larger frame size than DVD-Video supports.
HD-based DVDs also support both 4:3 and 16:9 sources, as well SD and HD video formats.
Using 16:9 sources in your project raises a number of issues that you need to be aware
of. Your main goal is to ensure that 16:9 assets play back correctly on 16:9 monitors and
as expected on 4:3 monitors (and that 4:3 assets play correctly on both monitor types as
well). Incorrect settings can lead to distorted video. For example, the video may appear
horizontally compressed (objects look “skinny”) or expanded (objects look “fat”).
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Chapter 4
Preparing Video Assets
This illustration shows the viewing options for a 16:9 asset.
16:9 monitor
16:9 aspect ratio
16:9 anamorphic
(The dashed line shows
the circle’s original size.)
16:9 letterbox
16:9 pan-scan
16:9 video on 4:3 monitors
This illustration shows the viewing options for a 4:3 asset.
4:3 monitor
4:3 aspect ratio
4:3 stretched
(The dashed line shows
the circle’s original size.)
4:3 video on 16:9 monitors
4:3 pillar box
Read the following sections to find out more about using 16:9 assets in your projects.