DVD Demystified

Glossary
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PAL Phase alternate line. A video standard used in Europe and other
parts of the world for composite color encoding. Various versions of PAL
use different scanning systems and color subcarrier frequencies (identified
with letters B, D, G, H, I, M, and N), the most common being 625
lines at 50 fields per second, with a color subcarrier of 4.43 MHz. PAL
is also said to mean “picture always lousy” or “perfect at last,” depending
on which side of the ocean the speaker comes from.
palette A table of colors that identifies a subset from a larger range of
colors. The small number of colors in the palette enables fewer bits to
be used for each pixel. Also called a color look-up table (CLUT).
pan and scan The technique of reframing a picture to conform to a different
aspect ratio by cropping parts of the picture. DVD-Video players
can automatically create a 4:3 pan and scan version from widescreen
anamorphic video by using a horizontal offset encoded with the video.
parallel path See PTP.
parental management An optional feature of DVD-Video that prohibits
programs from being viewed or substitutes different scenes
within a program depending on the parental level set in the player.
Parental control requires that parental levels and additional material
(if necessary) be encoded on the disc.
part of title In DVD-Video, a division of a title representing a scene.
Also called a chapter. Parts of titles are numbered 1 to 99.
PCI Presentation control information. A DVD-Video data stream containing
details of the timing and presentation of a program (aspect
ratio, angle change, menu highlight and selection information, and so
on). PCI and DSI together make up an overhead of about one Mbps.
PCM An uncompressed, digitally coded representation of an analog signal.
The waveform is sampled at regular intervals, and a series of
pulses in coded form (usually quantized) are generated to represent the
amplitude.
PC-TV The merger of television and computers. A personal computer
capable of displaying video as a television.
pel See pixel.
perceived resolution The apparent resolution of a display from the
observer’s point of view, based on viewing distance, viewing conditions,
and physical resolution of the display.
perceptual coding Lossy compression techniques based on the study
of human perception. Perceptual coding systems identify and remove
information that is least likely to be missed by the average human
observer.