Frequently Asked Questions About HDTV

Are Local TV Stations Broadcasting in HDTV?

Many local stations are transmitting digital signals. However, transmitting a digital signal does not mean transmitting an HDTV signal. Some stations are using the new bandwidth to broadcast several

standard-definition channels. Most stations, however, once they begin broadcasting in digital, are offering HD content from their parent station, that is, CBS, ABC, NBC, Fox, WB, UPN, or PBS.

Aspect Ratio? Resolution? What Does All That Mean?

The aspect ratio of a television screen is the ratio of its width to its height. The standard television screen is 4 units wide for every 3 units tall, so its aspect ratio is 4 x 3 or 4:3.

However, many HDTVs have an aspect ratio of 16:9 (meaning that the screen is 16 units wide for every 9 units tall).

The resolution of an HDTV screen indicates the amount of detail that the screen can display. This resolution is identified by the number of display lines on the screen. For example, 1080i means that the screen shows 1080 lines in interlaced format, and 480p means that the screen shows 480 lines in progressive format.

Progressive and interlaced format describe the technique that your HDTV uses to “paint” the picture on the screen. Interlaced format updates half of the lines on the screen with every new video frame. In one frame, an interlaced screen will update all of the odd-numbered lines on the screen. In the next frame, it updates all of the even-numbered lines.

By contrast, progressive format updates each line on the screen every time the frame changes.

Your set-top can display the following formats:

•1080 lines, interlaced (1080i)

•720 lines, progressive (720p)

•480 lines, progressive (480p)

•480 lines, interlaced (480i)

Standard Screen HDTV

Wide Screen HDTV

(4:3 Aspect Ratio)

(16:9 Aspect Ratio)

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