Television and Video Glossary M-O

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Macro -- A group of commands, or signals, chosen from the repertoire of a remote control, which can be executed/sent in sequence with the touch of one button.

Macroblock -- In a video compression scheme, a group of spacially adjacent pixels, usually forming a rectangular block, processed more or less together and somewhat separately from other pixels.

Macroblocking -- Pixellation, q.v.

Macrovision -- Trademark for a video encoding used to inhibit copying of video programs, particularly programs on DVD. A VCR has difficulty maintaining synchronization and black level when it encounters Macrovision encoding.

Maltese Cross -- An alternative mechanism to the pulldown claw for advancing film one frame at a time past the projector or camera gate. It consists of a square cam with inward bowed sides and with radial slots cut in the corners, alongside a continuously rotating disk with a single eccentric pin that engages the square cam by sliding in and out of the latter's slots. One revolution of the disk produces a 90 degree rotation of the square cam. To keep the square cam (and the film held by sprockets linked to the square cam) still for most of the duty cycle, between pin engagements, the related disk has attached to it a concentric circular cam with a bite taken out of it, said circular cam contacting and matching the radius of the nearest bowed side of the square cam, except when the pin is engaging the square cam.

Matte -- A means of covering up part of an image or film frame. In motion picture photography and video it (as plural) generally refers to the aperture plates or other means of hiding from view the top and bottom and/or side edges, for example to hide extraneous material resulting from filming what should be a wide screen movie using film frames with a lesser aspect ratio.

Memory or Memories (for video/audio) -- (1) Another word for "preset" q.v. (2) Ability of, or place in the mechanics or electronics of, a TV set or other electronic device to store (remember) custom settings made by the user, for example separate brightness and contrast adjustments for dark room versus lighted room viewing.

Micro LED -- An improvement over the (organic) OLED technology with no back lighting where the LEDs themselves are of more rugged inorganic composition and achieving increased brightness. Nearly microscopic light emitting diodes form individual self emitting pixels with the best sets having red, green, and blue subpixels at each pixel location. As of 2023 Micro LED has not been developed to where it can compete with OLED in terms of price and availability. Micro LED and Direct View LED are somewhat the same where in 2023 Micro LED has been used to refer to consumer displays including 4K and size less than 100 inches diagonally.

Mini LED -- An improfement over the original LED TV (sometimes called Direct LED) where the back light panel has a few hundred to a few thousand zones as opposed to several or dozens of zones to allow a finer division of dimmer zones for mainly darker picture content and brighter zones for mainly brighter picture content and in turn improve the contrast and dynamic range.

Moire Patterns -- Alternating and repeating blurred and clear areas of subject matter with uniform thin stripes or small polka dots, as seen on the screen. This occurs because the stripes or dots on the subject are spaced slightly differently from the scan lines or pixels on the screen and some of these features line up with the scan lines or pixels while others don't.

Monitor -- A person whose duty it is to observe, or equipment that makes it easier (or possible) for said person to make the desired observations. A "television monitor" can be simply a TV set without a tuner (channel selector) or more often these days it is a TV set that has additional video inputs to accept signals other than through its tuner. "Studio monitor" usually refers to an ordinary speaker system, that is, for monitoring audio. The term "television monitor" seems to suggest but really does not stand for better quality. (The full correct term for the standard TV set with tuner is "television receiver".)

Moth Eaten -- Loss of coloration in random places of what should be a more or less solid colored area, the most likely cause being deficiencies in analog video comb filtering. The effect is suggestive of (wool) cloth with holes in it due to attack by moth larvae.

Motion Adaptive -- Refers to de-interlacing line doublers and analog comb filters whose processing strategy or formula varies, where coincidentally the optimum processing depends on whether the subject matter depicted was stationary/steady or moving/changing. The best devices may vary their processing dozens of times within a single scan line or row of pixels. The device must digitize more than on video field, save (buffer) them on a rolling basis, and compare the content in small groups of pixels to determine whether subject matter was moving or not. More on line doublers. More on comb filters.

Motion Compensation -- An artifical intelligence interpolation procedure to construct an intermediate image for a new intervening frame for a motion picture, showing a "moving" subject in an intermediate position between the positions shown in two original consecutive frames. For some applications (de-interlacing) just the even scan lines or just the odd scan lines might be interpolated using motion compensation given the original odd lines and the original even lines as the content of two consecutive fields.

MPA, Maximum Pixels (picture elements, picture details) Across -- (new) My own term for labeling horizontal resolution in terms of the entire screen width. This is to establish a distinction from the traditional lines of resolution measurements across the largest circle that fits in the screen.

MPAA (Motion Picture Association of America) -- An organization, primarily of executives of the major movie making houses, which sets policies and standards for movies, including for movies' distribution and broadcast. MPAA also developed the audience suitability ratings: G (general) for all ages, PG for all ages but with parental guidance suggested for minors, PG-[13] for parental guidance for viewers under the specified age [e.g. 13], R (restricted) for theaters to not admit minors not accompanied by an adult, X for theaters to not admit minors at all.

MPEG (Moving Pictures Experts Group) -- (1) An organization, or more correctly a large enough collection of groups that could be called an institution, which among other things developed various data encoding and compressing schemes so an full length movie could be recorded on a five inch disk (a DVD). (2) The standards and the various encoding and compressing schemes developed by MPEG; they have each been given different names such as MPEG-2.

MTS (Multi-channel Television Sound) -- A standard for providing a second audio channel, for such purposes as stereophonic sound or bilingual audio tracks, on a (n analog standard broadcast) TV channel.

Multicasting -- Transmission of more than one program on the same channel, using such techniques as subcarriers and the formats provided in ATSC digital broadcasting. For example ATSC permits up to six shows (in standard definition) to be broadcast on a channel that could carry one NTSC (analog) show.

Multipath -- Copies of a broadcast signal arriving at the antenna delayed in time after bouncing off of other objects such as distant hills, the received result being ghosting on the screen.

Multiplex -- Theater building or complex with several theaters or auditoriums.

Multiplexer; Mux-- An electronic device used to transmit two signals or groups of signals on the same line where they would otherwise conflict with each other. If the frequency ranges of the signal groups overlap, a multiplexer might shift the frequency range of one signal, for example given two cable TV systems that each use channels 1 through 99, one system's signals could be transposed onto channels 101 through 199. A "de-multiplexer" aka "demux" separates the frequency groups, shifting the modified signal(s) back into its (their) original frequency ranges if needed.

Must-Carry -- Refers to broadcasts, generally of stations local to the subscribers, that cable and satellite TV providers are obligated to include with their complement of channels. Generally the obligation does not exist if the station does not wish to provide the programming at no charge to the cable company.

Glossary N

NAB -- (1) National Association of Broadcasters. (2) Equalization standards for analog tape recording developed by the NAB.

Narrow Band Color -- Analog video color signals limited to roughly 0.5 MHz allowing up to about 50 color changes across the screen, prior to modulation for composite video. All consumer analog videotape formats including Hi-8, and over 95% of analog color TV sets, used narrow band color circuitry.

NARTB -- National Association of Radio and Television Broadcasters, former name of the NAB.

Native -- Not counting, or prior to applying, any of: scaling, upconversion, downconversion, encoding, decodiing, modulation, demodulation, etc. For example the native resolution of "720p HDTV" is 720 pixels high by 1280 pixels wide but a particular TV set with a native 4:3 aspect ratio resolution of 640 by 480 on an LCD panel can convert a 720p 16:9 program to fit by displaying half the program's resolution horizontally and vertically, 640 by 360.

Negative Feedback -- The feeding of a small amount of an amplifier's output back to its input out of phase, the purpose is to cancel out some of the distortion (notably even harmonics) the amplifier may introduce.

Neo -- As used here, an advertising term to stand for new or novel relative to a similar technology that just preceded it.

960H -- A family of video formats with (or resolving) 960 pixels across and 480 to 580 pixels (or scan lines) high depending on whether compatibility is needed with NTSC, 480p, PAL or a few other standard definition formats. Used primarily for video surveillance applications. First introduced by Sony in 2009 to go with wide angle surveillance cameras.

Nit -- Measure of light output off of video displays, notably LCD panels. One nit stands for the level of illumination as seen on a uniformly lit panel where the sum total of light reflecting off of or emitted by one square meter (about 10-3/4 square feet) of panel or screen area is approximately equal to the sum total of light (about 12-1/2 lumens) given off by a lit candle (equal to the light output of a candle with certain standard characteristics). See, also, Foot Lambert.

Notch Filter -- An electronic filter that suppresses a small portion of a frequency range. A common use is as an inexpensive substitute for a video comb filter, where the frequencies used by the color information in an analog composite video signal are prevented from entering the luminance amplifier.

NTSC (National Television System Committee) -- U.S. government and industry committee which defined the 525-line 60 (59.94) interlaced fields per second analog broadcast TV standard in the 1950s. (This format is referred to as NTSC.) Of the 525 scan lines, 480 (give or take a few) contain the picture and the rest contain synchronizing information, hold the encoded closed caption text, and provide a time delay to move the electron beam back to the top of the screen. NTSC was used mainly in North America and Japan. Originally 30 frames per second, the standard was changed slightly to 29.97 frames per second at the time color was introduced since that change made it easier to incorporate the color information into what is now a composite video signal. The change was so small that practically all older TV sets continued to receive the signal properly without loss of vertical hold.

Numbering Scheme (and disclaimer)-- There are several numbering schemes for NTSC scan lines as seen in textbooks. A few are described below. The scheme we use is (a).

(a) Odd numbers between 1 to 483 inclusive denote lines for the first field, then odd numbers from 485 to 525 denote a vertical retrace interval, then even numbers from 2 to 482 denote the second field, then even numbers from 484 to 524 inclusive make up a vertical retrace interval.

(b) A retrace interval comes first, using odd scan lines from 1 to 41 inclusive, then odd lines 43 to 525 inclusive make up the first field, then even lines 2 to 42 make up a retrace interval, then even lines 44 to 524 make up the second field.

(c) Scan lines numbered consecutively 1 to 21 make up a retrace interval, lines numbered 22 to 263 make up the odd field, the following retrace interval consists of lines numbered 264 to 284, the lines of the even field are numbered 285 to 525.

In the above examples the picture may occupy up to 483 scan lines. If it does not occupy all 483 allowed scan lines, which extra lines are left black may vary depending on the make and model of equipment. There are other standards with slighly different numbers of active scan lines, such as:

(d) Scan lines numbered consecutively 1 to 20 make up a retrace interval, scan lines 21 to 262 and half of scan line 263 make up the odd field. The rest of line 263, lines 264 to 282, and half of line 263 make up a retrace interval, and the other half of line 263 and lines 264 to 525 make up the even field. Picture content including the half lines occupies 486 different scan lines with an "even field" (half) line uppermost and an "odd field" line lowermost..

Nyquist Frequency -- In digital processing, half the sampling rate (where one sample equals one cycle). Its significance is that all content above it must be filtered out of the source material prior to the analog to digital conversion at the start of processing, otherwise artifacts will be produced.

Glossary O

OAR -- Original Aspect Ratio.

"Object" (on the screen) -- In the subject matter of a picture, a line or a patch of color. When quality of reproduced pictures is discussed technically, it is often necessary to think about small parts as hair, nose, arm, shirt, shoe, or even "iris of the eye" as opposed to "person". It is like having to deliberately not see the forest because of the trees.

Octave -- A frequency band consisting of any starting frequency extending up to a frequency twice the starting frequency, or down to a frequency of half of the starting frequency. In an electronic context "octave" is used to describe a filter's behavior such as attenuating three (more) dB per octave (up or down).

OLED -- Organic LED -- Refers to TV sets and video displays with individual light emitting diode elements in each pixel position (actually red, green, and blue sub-pixels). There is no back light panel as in an "LED TV" or an "LCD TV" set. "Organic" refers to the complex carbon containing moleculss in the materials within the LED elements since carbon is the most fundamental chemical element leading to the development of living organisms on Earth. At the time (pre-2022), ordinary (inorganic) LEDs could not be manufactured small enough and bright enough to be the actual pixels.

Omnidirectional -- Having equal sensitivity to sounds or signals coming from any direction or, in the case of broadcasting antennas, radiating energy equally in all directions. May be understood to be or be qualified as two dimensional (a circular pattern) as opposed to three dimensional (a spherical pattern).

120Hz -- LCD technology providing for refreshing the screen approximately 120 times a second rather than 60. (One humdred as opposed to 50 Hz for regions where 50 Hz AC power is used.) The original purpose was to perform light to dark transitions slightly in advance to reduce smeared or blurred motion. (Dark to light transitions were not advanced.) Also, 24 frame per second material can be presented with each frame receiving equal time on the screen as opposed to using 3-2 pulldown. As of 2008 not all TV sets with 120 Hz offer this last feature.

Open Matte -- Video edition of a movie originally filmed soft-matte (q.v.) where more material above and below what should be shown in the theater is included to fill a TV screen with a different aspect ratio (notably 4:3).

Operating System -- The supervisory program such as Windows XP (TM) that is always running in a computer that is turned on and ready for use and that starts and stops other programs as needed. Contrasted with applications programs (apps) that are running only when someone wishes to use them, and "drivers" which are running only when another device such as a printer is in use.

Order of Magnitude -- A tenfold increase or 90% decrease; a decade, q.v. Frequency ranges: Medium frequency 316 to 1000 KHz (1 MHz) and 1.0 to 3.16 MHz; High frequency 3.16 to 10.0 MHz and 10.0 to 31.6 MHz; Very high frequency 31.6 MHz to 100 MHz and 100 to 316 MHz, etc. are in orders of magnitudes or as broken down here, pairs of one-half orders of magnitude. A one-half order of magnitude increase is an increase by a factor of the square root of ten, approximately 3.16, that is, if you multiply by this same number (the square root of ten) twice you get a one order of magnitude or tenfold increase.

Organic Light Emitting Diode -- LED using organic (carbon containing) compounds and chemicals to obtain the desired color of light output. The importance for TV is that the OLEDs, unlike current inorganic LEDs, can be made small enough to be the actual pixels on the screen.. See OLED.

Original Aspect Ratio -- The aspect ratio that the artistic director intended for a motion picture.

OS -- Operating System, q.v..

OTA -- Over The Air.

Overscan -- The adjustment of a CRT TV set so that all four edges of the video frame are slightly outside the screen. This was done by TV manufacturers decades ago when TV pictures shrank if the power line voltage dropped, the latter occurring often when everyone was using a lot of electricity. With overscan, there would still be enough picture to completely cover the screen when the picture shrank, and viewers stopped complaining that TV sets were defective.. However program material at the edges of the screen is lost. Still, TV producers keep important material away from the edges of the video frame, and many video cameras have marked in their viewfinders a "safe area". Sometimes the electronics in the TV set are deficient (producing rounded off horizontal and/or vertical sweep sawtooth waveforms) that the extreme edges of the picture are "squished" and overscan is deliberately used to hide this distorted material outside the screen borders.

Over the Air -- Broadcasting using a transmitter and antenna (not on a satellite) directly to the end users who use antennas to receive the signal. Also called Terrestrial.

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