Sony DCR-DVD200 DVD Handycam Technology Handbook - Page 20

GLOSSARY GLOSSARY ❏ Bit Rate The amount (measured in "bits") of data that flows in a specified period of time. For video recording and playback, which requires a large amount of data, bit rate is expressed in Mbps ("megabits per second"). In general, a higher bit rate results in higher-quality picture and sound. Bit rate can also be constant or variable. ❏ Coding In a digital video or audio signal, coding (or encoding) refers to the process of converting data from one form to another -- for example, into a compressed form so more data can be recorded and stored on a DVD disc. During playback, the compressed data is decoded to its original form. ❏ Constant Bit Rate Constant Bit Rate (CBR) means that all scenes are converted at the same rate; its purpose is to simplify the coding and decoding process. ❏ Dolby AC-3 The audio system used in DVD Handycam recordings. In the Dolby AC-3 system, audio can be recorded in 2-channel stereo, monophonic, or 5.1 channel surround sound (using six speakers for front left/right, center, rear left/right, and subwoofer). Audio compression only takes place in the frequency range beyond human hearing. ❏ DVD Applications DVD is a multipurpose medium used for storing moving and still images, audio and data. Its official name is "Digital Versatile Disc." There are various applications for DVD discs, including high-capacity storage of computer software and data. DVD video applications include DVD-Video, used for high-quality commercial recordings, and DVD-VR (Video Recording), used for personal video recordings that can be re-written (recorded more than once) and edited. ❏ DVD Capacity CD-sized DVD discs (4-3/4" or 12cm in diameter) can have one or two sides, and each side can contain one or two recordable layers. For a single-sided disc, dual-layer recording allows for up to 8.5 GB of data. For a double-sided disc, single-layer recording holds up to 9.4 GB. A doublesided disc with two recording layers can hold up to 17 GB of data. DVD Handycam camcorder use smaller 3-1/8" (8cm) discs. A double-sided DVD Handycam disc has one recording layer per side and holds up to 2.8 GB of data; it allows up to 2 hours of recording. ❏ DVD Formats DVD discs for video recording exist in various formats or standards. DVD-ROM is a playback-only format used for commercial movies. DVD-R is a format that can be recorded only once. DVD-RW can be recorded, edited and re-written (re-recorded). DVD-RAM, DVD+R and DVD+RW are alternate recordable formats not compatible with Sony DVD Handycam camcorders, which use only discs that conform to DVD-R and DVD-RW standards. ❏ DVD-Video The application for DVD recordings that do not require editing. DVD-Video allows up to 2 hours of high quality moving images and sound on a single disc, using MPEG 2 coding for movies and Dolby AC-3 (Dolby Digital 2-Channel) or linear PCM recording for sound. DVD-Video is an optical disc format that also allows for special playback features such as multiple screen ratios, captions, language options, and simultaneous multi-angle viewing of a scene. ❏ DVD-VR The application for which Sony DVD Handycam camcorders are designed. DVD-VR (or DVD Video Recording) provides added in-camera capabilities such as re-recording, editing, playlist display, etc. ❏ Finalizing Finalizing a disc enables its recorded contents to be played back on other equipment. Once finalized, DVD-R and DVDRW discs are read as though they were commercial recorded DVD movies -- allowing them to be played back on most DVD players. A finalized disc can no longer be re-recorded, but DVD-RW discs can be "unfinalized" to return them to recordable state. ❏ Groove/Land On a DVD disc, "groove" describes the spiral field where data is written to a recordable layer; "land" describes areas where data is not written. In the case of DVD-ROM, reading is carried out by an optical pickup following "pits" in the surface of the disc. In the case of DVD-R and DVD-RW, reading is carried out by an optical pickup following grooves in the surface of the disc. ❏ Initializing Initializing a disc allows the disc to be recorded or written on. Initializing a previously recorded disc will erase all existing data on the disc. DVD-R discs to not need to be initialized. DVD-RW discs must be initialized. The DVD Handycam camcorder system provides an "initializing" prompt each time a new DVD-RW disc is inserted. 20 DVD Handycam TECHNOLOGY HANDBOOK