Dictionary of Technical Terms - I
inbetweening (key frame interpolation)
Given two or more key frames, inbetweening is the act of generating the intermediate field rate information to cause the image to change from one key frame to the next. Unit of measure of length. One inch equals one twelfth of a foot or 25.4 millimeters. The ratio of the velocity of light in a vacuum to the velocity of light in a given medium. A menu for setting the proper editing system operating conditions at the start of an edit session. A solid state semiconductor device consisting of at least one p-n junction capable of emitting coherent or stimulated radiation under specified conditions. The device incorporates a resonant optical cavity. The beginning of an edit; the first frame that is recorded. See return loss. A routing switcher or auxiliary bus used to expand the number of video or key inputs that can feed an input of a digital picture manipulator or keyer. Many keyers only accept one key source and fill, but by connecting an input selector to those inputs, many more source and fill signals become available just by selecting crosspoints on the input selector. A device's input loops back out so that the incoming signal can be sent elsewhere. A key fill signal. An edit mode in which the time code and control track already existing on the record tape are not replaced during the editing process. The system edits using the pre-recorded control track and time code. A GVG editor command that takes an edit in the Mark Table and puts it into the Edit Decision List just after the line being pointed to. Signal loss within a circuit. Usually expressed in decibels as the ratio of input power to output power. An electronic device in which both active and passive circuits are contained in a single miniature multi-pin package. Used in fiber optics as a method of transmission in which the analog signal directly modulates the light source. Device or circuit used to interconnect two pieces of equipment. Short for interlaced scanning. Also called line interlace. A system of video scanning whereby the odd- and even-numbered lines of a picture are transmitted consecutively as two separate interleaved fields. A difference in propagation time of photons traveling on different paths in an optical fiber.intermodulation distortion (IMD)
Distortion that results when two or more pure tones produce new tones with frequencies representing the sum and/or difference of the original tones and their harmonics. In digital video, the creation of new pixels in the image by some method of averaging the values of neighboring pixels. This is necessary when an image is digitally altered, such as when the image is expanded or compressed. The time of edit start. Input/output. Typically refers to sending information or data signals to and from devices. Information provider.IRE (Institute of Radio Engineers)
Units of measurement dividing the area from the bottom of sync to peak white level into 140 equal units. One-hundred-forty IRE equals 1 volt peak-to-peak. The range of active video is 100 IRE. Integrated Services Digital Network. In videotaping, to record the output of each camera in a multiple-camera shoot on its own separate VTR. International Standardization Organization. A timing device that corrects for small timing errors. International Telecommunications Union. An international broadcast standards committee that replaced the CCIR. Formerly known as CCIR 601. An international standard for component digital television from which was derived SMPTE 125M (was RP-125) and EBU 3246E standards. This International Telecommunications Union (ITU) recommendation defines the sampling systems, matrix values, and filter characteristics for both Y, B-Y, R-Y and RGB component digital television. Formerly known as CCIR 656. The physical parallel and serial interconnect scheme for ITU-R BT.601-2 (CCIR 601). ITU-R BT.656 defines the parallel connector pinouts as well as the blanking, sync, and multiplexing schemes used in both parallel and serial interfaces. Reflects definitions in EBU Tech 3267 (for 625 line signals) and in SMPTE 125M (parallel 525) and SMPTE 259M (serial 525). Interexchange carrier.
