HD Player
Appendix D: Specifications
110
Rev. 6.8
Glossary
The following section contains definitions for some common terms that may be encountered during the use of the
HD Player and other articles relating to MPEG and digital video.
Anti-aliasing
The smoothing and removing of aliasing effects by filtering and other
techniques. Most, but not all, DVEs and character generators contain anti-
aliasing facilities.
Artifacts
Unwanted blemishes in a video image. In the analog video world this might be
noise, snow, spots for example. In the MPEG digital word artifacts are typically
blocking or lack of detail caused by the compression process.
See also,
Compression Artifacts.
ASCII
American Standard Code for Information Interchange. A standard code for
transmitting data, consisting of 128 letters, numerals, symbols, and special codes
each of which is represented by a unique binary number
ATSC
Advanced Television Systems Committee. Formed to establish technical
standards for advanced television systems, including digital high definition
television (HDTV). 1750 K Street NW, Suite 800, Washington, DC 20006. Tel:
202-828-3130. Fax: 202-828-3131.
Email:
atsc@atsc.org
.
Internet:
www.atsc.org
.
Aspect Ratio
The ratio of the width of a picture to it’s height. In standard resolution television
this is typically 4:3. For HDTV the ratio is 16:9. The increased width of the
image relative to the height has lead to the frequent use of “wide screen” to refer
to an HDTV display.
Baud
A unit of signaling speed equal to the number of signal events per second. Baud
is equivalent to bits per second in cases where each signal event represents
exactly one bit. Often the term baud rate is used informally to mean baud,
referring to the specified maximum rate of data transmission along an
interconnection. Typically, the baud settings of two devices must match if the
devices are to communicate with one another.
B frames
Bi-directional predictive frames used in the MPEG-2 signal. They are composed
by assessing the difference between the previous and the next frames in a
television picture sequence. As they contain only predictive information, they do
not make up a complete picture and so have the advantage of taking up much
less data than I frames. However, to see that original picture requires a whole
sequence of MPEG-2 frames to be decoded.
See also: I frames, P frames, MPEG.
Bit
Binary digit. The smallest unit of data in a digital system. A bit is a single one or
zero. A group of bits, such as 8-bits or 16-bits, compose a byte. The number of
bits in a byte depends upon the processing system being used. Typical byte sizes
are 8, 16, and 32.
Bit Depth
The number of levels that a pixel might have, such as 256 with an 8-bit depth or
1,024 with a 10-bit depth.
Bit stream
A continuous series of bits transmitted on a line.
Black Burst
Black burst is a composite signal that simply contains a black picture. A Black
burst signal is typically used to synchronize (genlock) video equipment together.
