Acomdata.com PDVD7 technical specifications Glossary of Technical Terms

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GLOSSARY OF TECHNICAL TERMS

AC-3 (Active Coding-3) - An audio encod- ing technology developed by Dolby Laboratories. AC-3 provides six channels of audio (known as 5.1) for front left, front right, front center, rear left, rear right, and subwoofer. AC-3 technology is used in Dolby Digital surround sound.

Aspect Ratio - The ratio of screen width to height. The aspect ratio of the standard TV screen is 4:3. The high-definition TV (HDTV) format is 16:9. When a widescreen movie is shown on a 4:3 TV there are two ways to dis- play the image:

•4:3 Letter Box - The entire original screen frame is displayed on the TV. However, this results in extra space (black bars) above and below the frame.

•4:3 Pan & Scan: The image fills the entire TV screen, but in order to do so, the original frame must be truncated at the sides,

so the viewer does not see the entire original screen image. When something important needs to be shown but it is located out of frame, the view pans over to reveal the hidden portion of the original image.

Bit Depth - The number of data bits used to encode a sample analog signal when it is con- verted into digital data. Higher bit depth means higher resolution and therefore higher fidelity.

CD (Compact Disc) - A digital audio disc that contains up to 74 minutes of hi-fi stereo sound. The most common platter size is 120mm (4.75") in diameter, recorded on one side, with individual selections playable in any sequence. Other forms of CDs, such as Video CD, stem from the original Compact Disc- Digital Audio (CD-DA) format.