The first step towards the disc
In authoring, the material which is supposed to be contained on the disc is prepared for further manufacturing processes. Language versions, soundtracks, animated menus etc. are created, but first of all it is a process of linking streams of image and sound. At this point, all the features of the disc are also shaped, features which decide its future value. Material processing also means adjusting to the size of the medium on which it will be pressed.
An image recorded in the case of a DVD disc uses one of the variants of the data-losing compression MPEG-2 is defined as Main Profile Main Level. On the DVD medium you can place up to 8 audio tracks with 48 or 96 KHz frequency, recorded in such formats as: Linear PCM (Pulse Code Modulation), MPEG-1 Layer 2 (Moving Picture Experts Group), Dolby Digital or Dolby Digital Theatre System. Special programs defined as encoders are used to change the format.
The sound on the disc, as need arises, can be monophonic, stereophonic but also multi-channel. Multi-channel sound requires quite a lot of space. This is why, during the authoring process, this data-losing compression is applied for such a type of sound. Better quality (a kind of rarity), ensures the formatting of sounds with Digital Theatre Systems (DTS), which means Digital Surround. However, more frequently used and more popular is the Dolby Digital System. The acquisition of multi-channel sound is a laborious process, but the final effect means that the recipient feels like a participant in the film’s plot.
The unquestionable advantage of DVD discs is the option to include up to 32 tracks with subtitles in many languages. This enables the preparation of one version of the DVD for a few countries at the same time. The cooperation of the authoring studio with translators and voiceover actors is not without significance at this stage.
The preparation of the film in which this voiceover actors becomes an integral element of the plot and does not disturb, is especially difficult and requires the work of professionals. It may seem trivial, but it is also especially relevant to prepare subtitles free from banal spelling mistakes and errors in stylistics.
Film material which will finally be on DVD medium is divided into titles. The chapter markings are also created (so-called scenes, of which there can be a maximum of 99), just to ensure access to the selected parts of these titles. An interactive menu (static or animated) allows navigation around the material contained on the medium. A favourite scene or language version can be easily and pleasantly found thanks purely to authoring.
The authoring studio is a place where security measures for future DVD Video discs is placed. Amongst them, these ones are mostly used, which protect against illegal copying. However, in fact there are two types of security measure. The first concerns protection against copying of the contents of the disc to another disc or hard disk, for example CSS (Content Scrambling System). In the case of CSS, partial security measures are placed in the authoring phase. The remaining part is added during mastering. The second type, for example Macrovision, concerns protection against re-recording of video material directly from a DVD player, for example to VHS tape recorders. Recently, a new security measure for DVD by Macrovision – RipGuard, has appeared.
For CD-ROM and DVD-ROM mediums, the security measures Safe Disc and Star Force are used. Another means of protection is the so-called regional lockout, which does not allow the playback of discs in another region other than that for which it was intended. Protecting our youngest, in the case of DVD, the so-called parental lockout is used, which does not allow children to play DVDs or selected scenes on their own.
Multi-camera screenshots, in the case of DVD, can also be prepared during authoring. Video tracks from different camera screenshots, which are concurrent on the same disc, are used for this. It allows for different options to watch the same film, however in the Polish market this possibility is seldom used. Thus, the scene of the car chase can take completely different dimensions – we can be witnesses from the outside but also from inside the car. The only condition for the creation of screenshots from many cameras is the possession of video materials of the same parameters.