Copyright Michael Karbo, Denmark, Europe.
Chapter 27. DVD - Video
A DVD is first and foremost known as a video disk. Every video kiosk has lots of films for hiring out on DVD, and most homes have players.
Plenty of audio, image and text
A single layer disk with a capacity of 4,7 GB can contain up to 135 minutes of top quality video with up to eight digital soundtracks in the formats PCM, Dolby Digital or DTS. The soundtracks can be in different languages or there can be soundtracks where the director, for example, talks about his thoughts while the film is played.
Subtitles have also become an important component, as a film can be subtitled into up to 32 different languages. A DVD film is, in fact, a brilliant tool for learning a foreign language, as you can freely choose a language both for sound and text.
DVD films, however, are often produced on double layered disks, where the capacity is 8,5 GB. This enables the storing of lots of extra film stuff (they are called features). The extra video sequences can contain interviews with directors, actors and much more. There can be alternative versions of the same film or parts of them and various camera angles to choose between. DVD media enables you to present a film in countless variations.
The film’s audio, images and data
A DVD video gives a much better image than an ordinary television or a VHS video, when it is shown on the television screen. There is a better resolution, sharper details and more splendid colours.
DVD video can actually support other image sizes but the films, we can buy and hire come with the highest resolution: 704 x 576 pixels.
The video image is encoded with the codec MPEG-2, which I have described earlier. The audio from films on DVD is usually of the type Dolby AC-3. We are also talking about surround sound so to get the full benefit of the film’s soundtrack, you should have a 5.1 surround system (see page 3).
Finally, protection of DVD-Videos against illegal copying has been attempted, but it failed. There was at one time a lot in the media about this case. It came out in 1999 that a fourteen-year-old Norwegian schoolboy had broken the encryption. In fact, he and others had just been trying to get DVD to work with the operating system Linux. This lead to the entertainment industry in 2002 trying (unsuccessfully) to get him convicted for a prison sentence.
Like all other digital media, DVD film can today be copied without problems; programs can be fetched from the net for this. This is a very unpleasant situation for film companies, which have great difficulties maintaining their rights. There are already Napster-like networks as, for example, Kazaa, where anyone (with a broadband net) can fetch illegal digital copies of all Bond, Hitchcock and other kinds of films. With a fast ADSL connection a film can be transmitted in two to three hours. The films are encoded in DivX/MPEG-4, where they don’t take more space than a normal CD.