DTV (Digital TV) Formats

What do all the numbers and letters mean?

Each format has a number and a letter:

Standard-Definition (SDTV) is 480i

Enhanced-Definition (EDTV) is 480p

High-Definition (HDTV) is 1080i and 720p

The number indicates resolution, or how many horizontal lines of information make up a single frame of video.

Generally speaking, the bigger the number, the sharper and more detailed the images. The letter indicates the method of picture scanning either interlaced or progressive.

Interlaced scanning (1080i & 480i) are the horizontal lines in a video frame that are divided into two groups, odd and even.

If you were to number the lines from the top to the bottom of the screen, one group would be the odd numbered lines, and the other would be the even numbered lines.

All the odd lines, then all the even lines, are updated
60 times a second, alternating between the two. This means the complete picture frame refreshes 30 times a second. This is not noticeable on smaller TV screens but can cause an obvious flicker on larger screens.

Progressive scanning (720p & 480p) refreshes the whole picture frame (all even and odd horizontal lies)
60 times a second. This gets rid of the flicker, but requires the TV to handle more information since twice as many picture frames are displayed each second.

Interlaced vs. Progressive Scanning


Disclosure Policy

Help Support Our Site

Return from DTV Formats to EZ Digital TV Home Page

How to select the right TV

Digital TV

Standard Definition (SDTV)

Enhanced Definition (EDTV)

High Definition (HDTV)