What is DVD Aspect Ratio?
DVD Aspect Ratio refers the ratio of an image with regards to its width and height as it is presented or projected on a display medium like TV and computer screens. In video format, the image display involved is done through thousands or millions of digital pixels depending on the video source and video display device. These image pixels are sometimes referred to as video dimensions with figures representing the width and height. Different dimensions or aspect ratios are used for different purposes. Standard television sets and computer monitors typically have lower video dimensions and/or video aspect ratios.

DVD or video aspect ratios are expressed in two numbers separated by a colon in between. The first number represents the video’s width size and the second number represents the height size of the same video. The most common DVD aspect ratio is 4:3 with 4 as the width and 3 as the height. This aspect ratio is used in standard televisions sets and generic computer monitors. Newer televisions sets with wider screens typically have aspect ratios of 16:9. In this case, although the actual image size may be the same, the display medium will stretch the image out to conform to the wider 16:9 aspect.

But since DVD-quality videos are made from different formats and technologies, not all will have aspect ratios that match the ratios on the television or computer screens. Even if a particular DVD movie is designed for a wide screen aspect ratio, it may still adjust to the standard 4:3 ratio if played on a standard TV monitor. To address this concern, most DVD players have built-in software to give people options on how to display a particular video. Like in videos designed for the 16:9 aspect ratios, the image display will be “letterboxed” when using standard monitors that can only handle 4:3 aspect ratios. In this example, the video will still appear wider but the height dimension will not be able to fill out the entire screen resulting to black borders on the top and the bottom.