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DVD-Video Overview
DVD-Video has become the format of choice for high
quality movies, TV series and music videos. |
DVD-Video was originally designed to meet the requirements of the
movie industry, in particular for a complete movie on a single 'compact'
optical disc. The use of MPEG-2 video compression has been shown to give
superlative results, far better than VHS and better than Laserdisc.
DVD-Video also offers full surround sound, subtitling, a choice of
display formats and user interaction for non-linear video applications.
DVD-Video players were launched in Japan in November 1996, in the USA
in March 1997 and in Europe in 1998. Since then DVD-Video has grown
faster than any other consumer electronics format in all these regions.
Thousands of titles and millions of players are now in use around the
world, with annual sales of players and discs almost doubling each year.
Video recorders that use recordable DVD discs are also available to
consumers.
The DVD-Video specification was written and is now maintained by the
DVD Forum working group WG1, which comprises a number of task groups
concerned with both read-only and recordable disc formats.
DVD-Video is now replacing VHS as the format of choice for
pre-recorded movies, both retail and rental and disc sales now exceed
VHS sales in many regions. With the introduction of recordable versions
DVD-Video is now set to replace the VHS for home video recording and
playback of pre-recorded video.
DVD-Video
Requirements
The Hollywood based Motion Picture Studio Advisory Committee defined the
following requirements for the DVD-Video format:
- 135 minutes on one side of a single disc (covering 99% of
all movies).
- Video resolution better than Laserdisc (LD).
- CD quality surround sound for true home cinema listening.
- 3 to 5 languages (audio) per title on one disc
- 4 to 6 subtitles per title on one disc
- Pan-scan, letterbox and widescreen formats
- Parental lockout features
- Copy protection
- Compatibility with existing CDs
- Chapter division and access (like Video CD)
- Manufacturing cost similar to current CD costs.
The Video CD format was studied,
but was rejected as it could not offer the necessary combination of quality and playing
time, hence the need for a new higher capacity disc format that has been realised in DVD.
The above requirements have all been met in the DVD-Video specification.
DVD-Video
Features
The DVD-Video specification provides the following features:
- 133 minutes of high quality MPEG-2 encoded video with
multi-channel surround sound audio.
- The choice of widescreen, letter box and pan & scan
video formats.
- Audio in up to 8 languages
- Subtitles for a further 32 languages
- Menus and program chains for user interactivity
- Up to 9 camera angles to give the user more choice
- Digital and analogue copy protection
- Parental control for protection of children
Most DVD-Videos also include extras that cannot be
included on a VHS, such as biographies, director's commentary, making of
the movie etc. An increasing number include DVD-ROM content, which
can range from links to relevant websites to a full game based on the
movie. The use of websites can allow the disc to be used in
different ways with updated text and graphics information on the website
complementing the video on the disc.
The DVD-Video specification is based on a pre-recorded DVD (DVD-ROM) with
UDF Bridge file system. A DVD-Video
can therefore be a DVD-5, DVD-10 or DVD-9 disc depending on the playing time required and
other factors. For overall playing times longer than 133 minutes (including additional
content), the dual layer DVD-9 offers a solution. A DVD-10 is more useful where widescreen and pan
& scan versions are required on the same disc. The use of the DVD-10 format is not
recommended for longer playing times, as the disc needs to be flipped to play the other
side.
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