DVD Glossary Part Part 7 (T

telecine - The process (and the equipment) used to transfer film to video. The telecine machine performs 3:2 pulldown by projecting film frames in the proper sequence to be captured by a video camera.

temporal resolution - The clarity of a moving image or moving object, or the measurement of the rate of information change in motion video. See resolution.

temporal - Relating to time. The temporal component of motion video is broken into individual still pictures. Because motion video can contain images (such as backgrounds) that do not change much over time, typical video has large amounts of temporal redundancy.

tilt - A mechanical measurement of the warp of a disc. Usually expressed in radial and tangential components: radial indicating dishing and tangential indicating ripples in the perpendicular direction.

time code - Information recorded with audio or video to indicate a position in time. Usually consists of values for hours, minutes, seconds, and frames. Also called SMPTE time code. Some DVD-Video material includes information to allow the player to search to a specific time code position.

title key - A value used to encrypt and decrypt (scramble) user data on DVD-Video discs.

title - The largest unit of a DVD-Video disc (other than the entire volume or side). Usually a movie, TV program, music album, or so on. A disc can hold up to 99 titles, which can be selected from the disc menu. Entire DVD volumes are also commonly called titles.

track buffer - Circuitry (including memory) in a DVD player that provides a variable stream of data (up to 10.08 Mbps) to the system decoders of data coming from the disc at a constant rate of 11.08 Mbps (except for breaks when a different part of the disc is accessed).

track pitch - The distance (in the radial direction) between the centers of two adjacent tracks on a disc. DVD-ROM standard track pitch is 0.74 mm.

track - 1) A distinct element of audiovisual information, such as the picture, a sound track for a specific language, or the like. DVD-Video allows one track of video (with multiple angles), up to 8 tracks of audio, and up to 32 tracks of subpicture; 2) one revolution of the continuous spiral channel of information recorded on a disc.

transfer rate - The speed at which a certain volume of data is transferred from a device such as a DVD-ROM drive to a host such as a personal computer. Usually measured in bits per second or bytes per second. Sometimes confusingly used to refer to data rate, which is independent of the actual transfer system.

transform - The process or result of replacing a set of values with another set of values. A mapping of one information space onto another.

trim - See crop.

tristimulus - A three-valued signal that can match nearly all colors of visible light in human vision. This is possible because of the three types of photoreceptors in the eye. RGB, YCbCr, and similar signals are tristimulus, and can be interchanged by using mathematical transformations (subject to possible loss of information).

TVL - Television line. See lines of horizontal resolution.

TWG - Technical Working Group. A general term for an industry working group. Specifically, the predecessor to the CPTWG.

TWG - Technical working group. A usually ad-hoc group of representatives working together for a period of time to make recommendations or define standards.

UDF Bridge - A combination of UDF and ISO 9660 file system formats that provides backward-compatibility with ISO 9660 readers while allowing full use of the UDF standard.

UDF - Universal Disc Format. A standard developed by the Optical Storage Technology Association designed to create a practical and usable subset of the ISO/IEC 13346 recordable, random-access file system and volume structure format.

universal DVD - A DVD designed to play in DVD-Audio and DVD-Video players (by carrying a Dolby Digital audio track in the DVD-Video zone).

universal DVD player - A DVD player that can play both DVD-Video and DVD-Audio discs.

user data - The data recorded on a disc independent of formatting and error-correction overhead. Each DVD sector contains 2048 bytes of user data.

UXGA - A video graphics resolution of 1600x1200.

VBI - Vertical blanking interval. The scan lines in a television signal that do not contain picture information. These lines are present to allow the electron scanning beam to return to the top and are used to contain auxiliary information such as closed captions.

VBR - Variable bit rate. Data that can be read and processed at a volume that varies over time. A data compression technique that produces a data stream between a fixed minimum and maximum rate. A constant level of compression is generally maintained, with the required bandwidth increasing or decreasing depending on the complexity (the amount of spatial and temporal energy) of the data being encoded. In other words, data rate is held constant while quality is allowed to vary. Compare to CBR.

VBV - Video buffering verifier. A hypothetical decoder that is conceptually connected to the output of an MPEG video encoder. Provides a constraint on the variability of the data rate that an encoder can produce.

VCAP Video Capable Audio Player - An audio player which can read the limited subset of video features defined for the DVD-Audio format. (Constrast with universal DVD player.)

VCD - Video Compact Disc. Near-VHS-quality MPEG-1 video on CD. Used primarily in Asia.

VfW - See Video for Windows.

VGA (Video Graphics Array) - A standard analog monitor interface for computers. Also a video graphics resolution of 640 x 480 pixels.

VHS - Video Home System. The most popular system of videotape for home use. Developed by JVC.

Video CD - An extension of CD based on MPEG-1 video and audio. Allows playback of near-VHS-quality video on a Video CD player, CD-i player, or computer with MPEG decoding capability.

Video for Windows - The system software additions used for motion video playback in Microsoft Windows. Replaced in newer versions of Windows by DirectShow (formerly called ActiveMovie).

Video manager (VMG) - The disc menu. Also called the title selection menu.

Video title set (VTS) - A set of one to ten files holding the contents of a title.

videophile - Someone with an avid interest in watching videos or in making video recordings. Videophiles are often very particular about audio quality, picture quality, and aspect ratio to the point of snobbishness.

VLC - Variable length coding. See Huffman coding.

VOB - Video object. A small physical unit of DVD-Video data storage, usually a GOP.

volume - A logical unit representing all the data on one side of a disc.

VSDA - Video Software Dealers Association. (See Appendix C.)

WAEA - World Airline Entertainment Association. Discs produced for use in airplanes contain extra information in a WAEA directory. The in-flight entertainment working group of the WAEA petitioned the DVD Forum to assign region 8 to discs intended for in-flight use.

watermark - Information hidden as “invisible noise” or “inaudible noise” in a video or audio signal.

White Book - The document from Sony, Philips, and JVC, begun in 1993 that extended the Red Book compact disc format to include digital video in MPEG-1 format. Commonly called Video CD.

widescreen - A video image wider than the standard 1.33 (4:3) aspect ratio. When referring to DVD or HDTV, widescreen usually indicates a 1.78 (16:9) aspect ratio.

window - A usually rectangular section within an entire screen or picture.

Windows - See Microsoft Windows.

XA - See CD-ROM XA.

XDS - (line 21)

XGA - A video graphics resolution of 1024 x 768 pixels.

XVCD - A non-standard variation of VCD.

Y - The luma or luminance component of video: brightness independent of color.

Y/C - A video signal in which the brightness (luma, Y) and color (chroma, C) signals are separated. Also called s-video.

YCbCr - A component digital video signal containing one luma and two chroma components. The chroma components are usually adjusted for digital transmission according to ITU-R BT.601. DVD-Video’s MPEG-2 encoding is based on 4:2:0 sYCbCr signals. YCbCr applies only to digital video, but is often incorrectly used in reference to the YPbPr analog component outputs of DVD players.

Yellow Book - The document produced in 1985 by Sony and Philips that extended the Red Book compact disc format to include digital data for use by a computer. Commonly called CD-ROM.

YPbPr - A component analog video signal containing one luma and two chroma components. Often referred to loosely as YUV or Y, B-Y, R-Y.

YUV - In the general sense, any form of color-difference video signal containing one luma and two chroma components. Technically, YUV is applicable only to the process of encoding component video into composite video. See YCbCr and YPbPr.

ZCLV - Zoned constant linear velocity. Concentric rings on a disc within which all sectors are the same size. A combination of CLV and CAV.