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This is referred to as a "sound mode icon,"
and this one in particular indicates the disc contains 1-channel Dolby
Digital audio (mono). A mono channel is often used for DVD content
such as director commentary.
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Disc contains 2-channel Dolby Digital audio (stereo).
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Disc contains 3-channel Dolby Digital audio (surround).
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Disc contains 5.1 Dolby Digital audio, i.e., surround
with a LFE (low-frequency effects) channel.
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Dolby Digital Surround EX, a system co-developed by
Dolby and Lucasfilm, was first used theatrically for Star Wars: Episode
1. Dolby Digital Surround EX soundtracks contain 5.1 channels of discrete
audio, plus an additional matrix encoded surround channel. These DVDs
are compatible with all playback systems and provide an enhanced surround
effect when used with a Surround EX enabled system.
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6.1 channel surround from DTS, a competitor to Dolby.
This format adds a rear center speaker to the surround sound package
found on selected music and movie discs.
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THX EX is 7.1 channel surround from Lucasfilm. There
aren't many movies encoded with 7.1 (all the new Star Wars films are),
nor many preamps to play it. You'd also have to add more speakers
to your system. If you have such a setup, can we come over?
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DTS was developed for “Jurassic Park” in
1993 and is the main competitor to Dolby Digital in the AV market.
DTS’ advantage over Dolby is its 3:1 compression versus 12:1.
Most current receivers and preamps are capable of playing both Dolby
5.1 and DTS surround DVDs.
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Stands for Meridian Lossless Packing, a lossless compression
scheme used on DVD-Audio to get the highest resolution surround sound
and stereo music from a DVD disc. DVD-Audio sounds better than the
16-bit audio on CDs.
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The disc is playable only in DVD players from region
1, i.e., North America. There are eight regions (seven geographical
and an eighth reserved for airlines, cruise ships, etc.).
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The disc is playable in DVD players from all regions
of the world.
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NTSC stands for the National Television Systems Committee,
and is the color video standard used in North America, Canada, Mexico,
and Japan. NTSC uses 525 horizonal lines of which only 487 make up
the active picture. It's an inferior video standard compared to PAL
(below).
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PAL stands for Phase Alternating Line, and is the TV
standard used in Europe and much of Asia. It was designed to correct
problems in the NTSC system. PAL uses 625 horizontal lines, of which
576 are used for the picture. In other words, it has roughly one sixth
more resolution than NTSC, resulting in better color and sharper resolution.
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The disc contains video content with an aspect ratio
of 1.33:1 (or 4:3). This is the basic dimension of a television monitor.
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The disc contains video content with an aspect ratio
of 1.78:1 (or 16:9), also referred to as "anamorphic widescreen."
In addition to 1.78:1, there are other anamorphic screen ratios such
as 1.66:1, 1.85:1 and 2.35:1 and 2.39:1 which you might see listed
on DVDs.
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The disc contains closed captioning for the hearing
impaired.
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We're all familiar with the DVD logo, and its many
variants (ROM, Video, Audio, etc.).
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You haven't seen any discs with this symbol yet, but
you will sometime in 2005. It stands for High Definition/High Density
DVD, the next-generation optical disc format, developed by an industry
consortium led by Toshiba and NEC. HD-DVDs are capable of storing
15GB of data, and use the MPEG4 codecs for compression.
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Another next-generation optical disc format that hopes
to replace DVD. Developed by Philips and Panasonic, Blu-ray Disc will
be a competitor to HD-DVD. Blu-ray Disc allows 29GB of data (nearly
twice HD-DVD), but it uses the MPEG2-based codecs, which are not as
efficient as MPEG4. The latter can reduce file size by two thirds,
meaning a 15GB HD-DVD disc can hold 180 minutes of high-definition
video, whereas a 29GB Blu-ray disc can hold 132 minutes. Will one
format beat out the other to become the replacement for DVD? Or will
they co-exist? Stay tuned... |
