Analog television is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness, colors and sound are represented by amplitude, phase and frequency of an analog signal.
The National Television System Committee (NTSC) developed the analog television format encoding system that was introduced in North America in 1954 and stayed in use until digital conversion. It is one of three major analog format television standards, the others being PAL and SECAM. All the countries using NTSC are currently in the process of conversion, or have already converted to the ATSC standard, or to DVB, ISDB or DTMB.
Phase Alternating Line (PAL) is a colour encoding system for analogue television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields per second, and associated with CCIR analogue broadcast television systems B, D, G, H, I or K. The articles on analog broadcast television systems further describe frame rates, image resolution, and audio modulation.
A signal generator is one of a class of electronic devices that generates electronic signals with set properties of amplitude, frequency, and wave shape. These generated signals are used as a stimulus for electronic measurements, typically used in designing, testing, troubleshooting, and repairing electronic or electroacoustic devices, though it often has artistic uses as well.
Colorburst is an analog video, composite video signal generated by a video-signal generator used to keep the chrominance subcarrier synchronized in a color television signal. By synchronizing an oscillator with the colorburst at the back porch (beginning) of each scan line, a television receiver is able to restore the suppressed carrier of the chrominance (color) signals, and in turn decode the color information. The most common use of colorburst is to genlock equipment together as a common reference with a vision mixer in a television studio using a multi-camera setup.
Composite video is an analog video signal format that carries standard-definition video as a single channel. Video information is encoded on one channel, unlike the higher-quality S-Video and the even higher-quality component video. In all of these video formats, audio is carried on a separate connection.
Genlock is a common technique where the video output of one source is used to synchronize other picture sources together. The aim in video applications is to ensure the coincidence of signals in time at a combining or switching point. When video instruments are synchronized in this way, they are said to be generator-locked, or genlocked.
Component video is an analog video signal that has been split into two or more component channels. In popular use, it refers to a type of component analog video (CAV) information that is transmitted or stored as three separate signals. Component video can be contrasted with composite video in which all the video information is combined into a single signal that is used in analog television. Like composite, component-video cables do not carry audio and are often paired with audio cables.
YPbPr or Y'PbPr, also written as YPBPR, is a color space used in video electronics, in particular in reference to component video cables. YPbPr is gamma corrected YCbCr color space ; the two are numerically equivalent but YPbPr is designed for use in analog systems while YCbCr is intended for digital video. The EOTF may be different from common sRGB EOTF and BT.1886 EOTF. Sync is carried on the Y channel and is a bi-level sync signal, however, in HD formats a tri-level sync is used and is typically carried on all channels.
U-matic is an analogue recording videocassette format first shown by Sony in prototype in October 1969, and introduced to the market in September 1971. It was among the first video formats to contain the videotape inside a cassette, as opposed to the various reel-to-reel or open-reel formats of the time. The videotape is 3⁄4 in (19 mm) wide, so the format is often known as "three-quarter-inch" or simply "three-quarter", compared to open reel videotape formats in use, such as 1 in (25 mm) type C videotape and 2 in (51 mm) quadruplex videotape.
Television encryption, often referred to as scrambling, is encryption used to control access to pay television services, usually cable, satellite, or Internet protocol television (IPTV) services.
The 405-line monochrome analogue television broadcasting system was the first fully electronic television system to be used in regular broadcasting. The number of television lines influences the image resolution, or quality of the picture.
A video signal generator is a type of signal generator which outputs predetermined video and/or television oscillation waveforms, and other signals used in the synchronization of television devices and to stimulate faults in, or aid in parametric measurements of, television and video systems. There are several different types of video signal generators in widespread use. Regardless of the specific type, the output of a video generator will generally contain synchronization signals appropriate for television, including horizontal and vertical sync pulses or sync words. Generators of composite video signals will also include a colorburst signal as part of the output.
The IRE unit is used in the measurement of composite video signals. Its name is derived from the initials of the Institute of Radio Engineers.
Sound-in-Syncs is a method of multiplexing sound and video signals into a channel designed to carry video, in which data representing the sound is inserted into the line synchronising pulse of an analogue television waveform. This is used on point-to-point links within broadcasting networks, including studio/transmitter links (STL). It is not used for broadcasts to the public.
A white clipper is a circuit in professional video products that limits the maximum amplitude of the luminance part of the analogue video signal to 1 volt. It is essential for both analogue recording and transmission of video material.
Differential gain is a kind of linearity distortion which affects the color saturation in TV broadcasting.
The output power of a TV transmitter is the electric power applied to antenna system. There are two definitions: nominal and thermal. Analogue television systems put about 70% to 90% of the transmitters power into the sync pulses. The remainder of the transmitter's power goes into transmitting the video's higher frequencies and the FM audio carrier. Digital television modulation systems are about 30% more efficient than analogue modulation systems overall.
This glossary defines terms that are used in the document "Defining Video Quality Requirements: A Guide for Public Safety", developed by the Video Quality in Public Safety (VQIPS) Working Group. It contains terminology and explanations of concepts relevant to the video industry. The purpose of the glossary is to inform the reader of commonly used vocabulary terms in the video domain. This glossary was compiled from various industry sources.
CCIR System A was the 405-line analog broadcast television system adopted in the UK and Ireland. System A service started in 1936 and was discontinued in 1985.
