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Glossary
Analog audio
An electrical signal that directly represents sound. Com-
pare this to digital audio which can be an electrical sig-
nal, but is an indirect representation of sound. See also
“Digital audio”.
Aspect ratio
The width of a TV screen relative to its height. Conven-
tional TVs are 4:3 (in other words, the screen is almost
square); widescreen models are 16:9 (the screen is
almost twice as wide as it is high).
Digital audio
An indirect representation of sound by numbers. During
recording, the sound is measured at discrete intervals
(44,100 times a second for CD audio) by an analog-to-
digital converter, generating a stream of numbers.
On playback, a digital-to-analog converter generates an
analog signal based on these numbers. See also “Sam-
pling frequency” and “Analog audio”.
DivX
DivX is a media technology created by DivX, Inc. DivX
media files contain compressed video. DivX files can
also include advanced media features like menus, subti-
tles, and alternate audiotracks.
Dolby Digital
Using a maximum of 5.1 channels of audio, this high
quality surround system is used in many of the finer
movie theaters around the world.
The on-screen display shows which channels are active,
for example showing 3/2.1. The 3 being the two front
channels and the center channel; the 2 being the sur-
round channels, and the .1 being the LFE channel.
DRM
DRM (digital rights management) is a type of server
software developed to enable secure distribution of paid
content over the web, recently incorporated by WMA
(Windows Media Audio).
DTS
DTS stands for Digital Theater Systems. DTS is a sur-
round system different from Dolby Digital that has
become a popular surround sound format for movies.
Dynamic range
The difference between the quietest and loudest sounds
possible in an audio signal (without distorting or getting
lost in noise).
Dolby Digital and DTS soundtracks are capable of a very
wide dynamic range, delivering dramatic cinema-like
effects.
EXIF (Exchangeable Image File)
A file format developed by Fuji Photo Film for digital
still cameras. Digital cameras from various manufactur-
ers use this compressed file format which carries date,
time and thumbnail information, as well as the picture
data.
File extension
A tag added to the end of a filename to indicate the type
of file. For example, “.mp3” indicates an MP3 file.
ISO 9660 format
International standard for the volume and file structure
of CD-ROM discs.
JPEG
A file format used for still images, such as photographs
and illustrations. JPEG files are identified by the file
extension “.jpg” or “.JPG”. Most digital cameras use this
format.
MP3
MP3 (MPEG1 audio layer 3) is a compressed audio file
format. Files are recognized by their file extension
“.mp3” or “.MP3”.
MPEG audio
An audio format used on Video CDs and some DVD
discs. This unit can convert MPEG audio to PCM format
for wider compatibility with digital recorders and AV
amplifiers. See also “PCM (Pulse Code Modulation)”.
MPEG video
The video format used for Video CDs and DVDs. Video
CD uses the older MPEG-1 standard, while DVD uses
the newer and much better quality MPEG-2 standard.
PBC (PlayBack Control) (Video CD only)
A system of navigating a Video CD through on-screen
menus recorded onto the disc. Especially good for discs
that you would normally not watch from beginning to
end all at once—karaoke discs, for example.
PCM (Pulse Code Modulation)
The most common system of encoding digital audio,
found on CDs and DAT. Excellent quality, but requires a
lot of data compared to formats such as Dolby Digital
and MPEG audio. For compatibility with digital audio
recorders (CD, MD and DAT) and AV amplifiers with
digital inputs, this unit can convert Dolby Digital, DTS
and MPEG audio to PCM. See also “Digital audio”.
