Other Digital Audio Devices 633The DVD can also end the concept of a fi lm as a single story because, unlike tape, it
can switch from one set of tracks to another very quickly, allowing fi lms to be recorded
with several options endings, for example. Different camera angles can also be selected
by the viewer from the set recorded on the disc, and displays of text, in more than one
language, can be used for audio and video tracks. Like CD and so unlike VCR, winding
and rewinding are obsolete concepts, and a DVD can be searched at a very high speed that
seems instantaneous compared to VCR. The disc is also smaller than a videocassette, does
not wear out from being played many times, and resists damage from magnets or heat.
● DVD for video uses MPEG-2 coding and decoding, but there is nothing to
prevent cut-price producers from coding with MPEG-1, producing the same video
quality as a VCR. Even MPEG-2, however, is a lossy compression method, which
sometimes shows in video quality as shimmering, fuzzy detail, and other effects.
● In contrast, DVD audio quality is excellent. DVD audio can optionally use CD
methods (PCM) with higher sampling rates for even better quality than CD.
Other options, used mainly in connections with fi lms, are Dolby Digital or DTS-
compressed audio.21.9.1 Regionalization
Unlike audio CD, DVD is more regionalized than we would wish. Taking a cynical view,
this is done to prevent European users from fl ying over to the United States to stock up
with DVDs at bargain prices. Film studios have taken the same attitude to DVD as the
record companies did to DAT—if you can’t ban it, cripple it. The offi cial reasons are that
regionalization prevents premature release of a fi le in another country and protects the
distribution rights of suppliers in different countries. Regionalization does not apply to
DVDs that consist purely of audio signals.
Apart from regional codes, DVDs must be designed to work with the type of color TV
coding that different countries use, so that DVDs have to be manufactured in NTSC,
PAL, and SECAM versions.
The DVD standard includes regional codes, and each DVD drive or deck is allocated a
code for the region in which it is marketed. A disc bought in one region will not play on
a deck/drive bought in another region, because the codes will not match. Several DVD
users in the United Kingdom have countered this by buying their DVD equipment in the
United States and then also buying the discs in the United States.