DVD Demystified

632
Glossary
and they do not propagate coding errors because they are not used as a
reference by other pictures.
bps Bits per second. A data rate unit.
brightness Defined by the CIE as the attribute of a visual sensation
according to which area appears to emit more or less light. Loosely, it is
the intensity of an image or pixel, independent of color, that is, its value
along the axis from black to white.
buffer A temporary storage space in the memory of a device that helps
smooth data flow.
burst A short segment of the color subcarrier in a composite signal that
is inserted to help the composite video decoder regenerate the color
subcarrier.
B-Y, R-Y The general term for color-difference video signals carrying
blue and red color information where the brightness (Y) has been subtracted
from the blue and red RGB signals to create B-Y and R-Y colordifference
signals. Refer to Chapter 3, “DVD Technology Primer.”
byte A unit of data or data storage space consisting of eight bits, commonly
representing a single character. Digital data storage is usually
measured in bytes, kilobytes, megabytes, and so on.
caption A textual representation of the audio information in a video
program. Captions are usually intended for the hearing impaired and
therefore include additional text to identify the person speaking, offscreen
sounds, and so on.
CAV Constant angular velocity. Refers to rotating disc systems in which
the rotation speed is kept constant, where the pickup head travels over
a longer surface as it moves away from the center of the disc. The
advantage of CAV is that the same amount of information is provided
in one rotation of the disc. Contrast with CLV and ZCLV.
Cb,Cr The components of digital color-difference video signals carrying
blue and red color information, where the brightness (Y) has been subtracted
from the blue and red RGB signals to create B-Y and R-Y colordifference
signals (refer to Chapter 3, “DVD Technology Primer”).
CBEMA Computer and Business Equipment Manufacturers Association
(Refer to Appendix C, “References and Information Sources.”)
CBR Constant bit rate. Data compressed into a stream with a fixed data
rate. The amount of compression (such as quantization) is varied to
match the allocated data rate, but as a result, quality may suffer during
high-compression periods. In other words, the data rate is held constant,
while quality is allowed to vary. Compare this to VBR.
CCI Copy control information. Information specifying if the content is
allowed to be copied.