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Glossary
Market introduction of this format
developed by JVC and presented in
1995 for the first time was repeatedly
delayed due to the unclear situation
regarding digital broadcasting stan-
dards and due to copyright prob-
lems.
DVB
Digital Video Broadcasting
DVB includes a packet of features for
broadcasting programs via a digital,
terrestrial network. DVB is the Euro-
pean equivalent of the American
ÆDTV.
DVCAM
Digital video tape format. DVCAM
is based on the
ÆDV FORMAT and
was developed by Sony. Sony
changed a number of DV parameters
for the DVCAM format. 4:2:0-sam-
pling and data reduction by means
of DCT was maintained, the Track
width, however was increased to 15
mm. The tape speed is higher (28.2
mm/s) which results in shorter play-
ing times compared with DV.
Depending on the cassette, they are
12, 64, 124, 164 or 184 minutes. DV
uses metal evaporated (ME) tapes.
DVCAM devices can also play DV
cassettes.
DVCPRO
Panasonic developed the digital
video tape format DVCPro on the
basis of the
ÆDV FORMAT. The tech-
nical data of the DVCPro standard
are similar to those of DV. There are,
however, some differences: DVCPro
uses a Track width of 18 mm. Tape
speed is 33.8 mm/s, i.e. almost twice
as fast as in the case of DV.
Moreover, DVCPro works with other
tape material, i.e. metal particle
tape. Other differences to DV: The
sampling ratio of DVCPro was deter-
mined at 4:1:1 and not at 4:2:0. In
doing so, the developers are trying
to reduce vertical chrominance
errors that appear as color smears
after repeated copying in DV. Also
the DVCPro Track frame looks dif-
ferent than in the case of DV:
DVCPro records an additional
ÆCTL and a cue margin Track. The
CTL Track has advantages for linear
editing, since shorter preroll times
can be realized with equal or even
better editing accuracy. The cue
Track serves as an additional analog
sound Track enabling the operator
to hear the playing sound of a video
recorder in jog and shuttle mode.
DVCPRO50
The digital vid eo tape format
DVCPro50 was developed by Pana-
sonic on the basis of
ÆDVCPRO. It
differs from other
ÆDV FORMATS in
that signal sampling is 4:2:2 and that
the video data rate corresponds to
50 Mbits/s.
For enhanced signal sampling qual-
ity and higher data rate, the tape is
played at double speed, thus reduc-
ing the running time per cassette by
50 % in contrast to DVCPro.
DVCPro50 in the PAL version
records 24 Tracks per frame, i.e.
twice as many helical Tracks as
DVCPro. DVCPro50 provides four
instead of two digital audio channels
for sound recording. They enable a
resolution of 16 bits/48 kHz.
DVD
Digital Versatile Disc.
Digital optical storage medium in
the form of an
ÆOPTICAL DISC. The
abbreviation was formerly used for
the term Digital Video Disc, but was
renamed later into Digital Versatile
Disc to emphasize the variety of pos-
sibilities of this disc.
The outer dimensions of the DVD
correspond to those of an audio CD:
diameter: 12 cm; 1.2 millimeters
thick.
DVD is characterized by its high
storage capacity. It can be manufac-
tured in various ways. The maxi-
mum version includes two layers on
each side on which the data is stored.
In this version the DVD can store 25
times as much information as the
corresponding audio CD. One
could, by making use of modern
technology, manufacture audio discs
with a playing time of 30 hours.
Feature films in good, digital image
and sound quality can be stored on a
DVD (
ÆDVD-VIDEO). DVD is also