Glossary of Home Theater Terminology
Glossary of Audio, Video and Home Theater Terms
There is a very large vocabulary of technical and descriptive terms that go with home theater. We've included the terms that you are most likely to encounter. If you are very technically involved you may find some of the more technical terms omitted from our list.
Click on a letter to jump to that section of our glossary
PAL - Phase Alternate Line.
The most widely used analog broadcast standard worldwide. Like NTSC (used
in North America & Japan) it is an interlaced signal, although
it differs in that it has 625 lines of resolution and 50 cycles
per second. Equipment that uses one standard cannot play the
other standard. There is a third standard, SECAM, used in France; PAL programming can be played on SECAM equipment, but only in black and white.
Pan and Scan - Widescreen films do not
easily fit onto standard 4:3 screens, so the film industry developed
a technique to scan the film and select the most important part of the
frame for transfer to video. Because the important part of the frame
is not always in the center, a technician must "pan" back and
forth in the frame to follow the action. Effectively, each frame is cropped
to the 4:3 aspect ratio and image falling outside that field is discarded.
Panavision - A process for
filming a widescreen (2.35:1) aspect ratio film onto 35mm film using anamorphic lenses.
Pb, Pr - Component video is
comprised by three signals. One signal is luminance which
is signified by "Y". The second signal is blue, represented by "B" and finally red, represented by "R". "P" describes an analog signal while "C" indicates a digital signal. Depending upon equipment and cables, the signals may alternatively be labeled as "B - Y " or "Cb" and "R - Y" or "Cr" respectively.
PCM - Pulse Code Modulation.
A method of encoding an audio signal into a digital format.
PCM is the method used to encode audio data onto CD.
Personal Video Recorder -
aka PVR, DVR and Digital Video Recorder. Similar to a VCR although
with much greater capabilities. A PVR records to an internal
hard disk drive. It can record and play back a different recording
simultaneously. With it you can pause live television and in
some cases record more than one show simultaneously. It allows
for easy set-up to record a program one time or on an ongoing
basis. While once a subscription product available from a small
number of companies like Tivo or Replay, many cable companies
and satellite systems are now offering the service.
Picture-in-Picture - aka PIP. A feature found on televisions that allow a second picture to be superimposed onto the primary image on screen. In order for the picture to display a different channel than the primary screen, a second tuner is required. The second tuner may be built into the television (2 tuner PIP) or the tuner from a VCR may used (1 tuner PIP).
Pillerbox - Black bars on all
four sides of the image. This occurs when a station broadcasts
an upconverted 4:3 aspect ratio program within a 16:9 frame.
PIP - See Picture-in-Picture.
Pixel - Refers to a "picture element." A discrete unit capable
of displaying a color or intensity different from those around
it. LCD screens are an example of a pixel based display; many
are 1280 pixels across and 720 pixels tall.
Pixel response time - The time it takes for
a pixel to switch from active to inactive. Slow response time,
more than 16 milliseconds, results in motion trails following
fast moving objects on screen.
Plasma - A technology used
for the creation of one of the two types of thin panel displays.
Plasma displays have two glass panels with roughly one million
pixels sandwiched between. Each pixel has three cells, one
red, one green and one blue. Each cell is filled with a gas
and when current is applied the gas emits UV rays which stimulate
the phosphors to glow. The process is similar to the way a
fluorescent light glows.
Plug - A male connector, as
opposed to a jack which is a female connector
PLUGE - Picture LineUp Generation
Equipment. The name of a test pattern used in adjusting the
picture black level.
Port - An opening in a loudspeaker
enclosure designed to improve sound quality.
Power Output - A measure, usually in watts, of the energy output
by an amplier. It may be expressed as watts per channel, or
the total for all channels combined.
Preamplifier - The term often
applied to the control section of a receiver or integrated
amplifier. The control section "pre" processes input
signals before sending them to the power amplifier.
Presets - On an AM or FM tuner,
memory settings to recall preselected radio station frequencies.
Prime - The components of a
video signal are represented by specific symbols, such as "Y" for luminance. If the signal has gamma compensation applied then a "prime" symbol
is added to denote modified signal. In the case of a gamma
compensated signal, it would be denoted as Y'.
Prime Disclaimer - In order to keep references
simple, the gamma compensation may be ignored and the apostrophe
Progressive Scan - An image that is painted
line by line in a continuous fashion. Compare to interlace
scan which paints every other line, requiring two scans to
create a complete image.
Projection Television - A
television thats projects an image onto a screen rather drawing
it directly on a phosphor coated screen (CRT). Projection TVs
can be front projection (onto a separate screen or wall up
to 20 feet away) or rear projection (onto a screen built into
the television housing).
Pulldown - See 3-2 Pulldown.
PVR - See Personal Video Recorder.