Video monitor
Encyclopedia
A video monitor also called a broadcast monitor, broadcast reference monitor or just reference monitor, is a display device
similar to a television set
, used to monitor the output of a video-generating device, such as playout
from a video server
, IRD
, video camera
, VCR, or DVD player
. It may or may not have professional audio
monitoring capability. Unlike a television set
, a video monitor has no tuner (television) and, as such, is unable independently to tune into an over-the-air
broadcast like a television receiver. One common use of video monitors is in television station
s, television studio
s, production truck
s and in outside broadcast vehicles, where broadcast engineers use them for confidence checking of analog signal
and digital signal
s throughout the system.
Video monitor
s are used extensively in the security industry with closed-circuit television camera
s (CCTV) and recording devices.
Common display types for video monitors
Common monitoring formats for security
at television or television studio
facilities, because they do not perform any video enhancements and try to produce as accurate an image as possible.
For quality control purposes, it is necessary for a broadcast reference monitor to produce (reasonably) consistent images from facility to facility, to reveal any flaws in the material, and also not to introduce any image artifacts (such as aliasing
) that is not in the source material. Broadcast monitors will try to avoid post processing such as a video scaler
, line doubling and any image enhancements such as dynamic contrast. However, display technologies with fixed pixel structures (e.g. LCD, plasma) must perform image scaling when displaying SD signals as the signal contains non-square pixels while the display has square pixels. LCDs and plasmas are also inherently progressive displays and may need to perform deinterlacing
on interlaced video signals.
Some Professional video broadcast monitors display information on screen, the current video signal format, they might be receiving i.e.: standard definition formats like 576i
, 480i
or high definition
formats like 720p
or 1080p
. They also have mechanical buttons to toggle
common aspect ratios like (4:3 or 16:9
), and underscanning or overscan
ning a picture to see lines in the vertical blanking interval
(VBI) of video, and check if subtitles in VBI were inserted properly or not. Modern broadcast grade professional monitors also have safe area
grid generators, to help position television
graphics, lower thirds
, within their respective areas i.e. graphics safe, title safe or action safe.
Common monitoring formats for broadcasters
Display device
A display device is an output device for presentation of information in visual or tactile form...
similar to a television set
Television set
A television set is a device that combines a tuner, display, and speakers for the purpose of viewing television. Television sets became a popular consumer product after the Second World War, using vacuum tubes and cathode ray tube displays...
, used to monitor the output of a video-generating device, such as playout
Playout
In broadcasting, playout is a term for the transmission of radio or TV channels from the broadcaster into broadcast networks that delivers the content to the audience...
from a video server
Video server
A video server is a computer based device dedicated to delivering video.Unlike personal computers, being multi-application devices, a video server is designed for one purpose; provisioning video, often for broadcasters. A professional grade video server records, stores, and playout of multiple...
, IRD
IRD
Ird may refer to the following:* Ird , a Bedouin honor code for women* Ird : Someone who lives in a state of total delusion. Closely related to narcissistic personalities.* Ird, alternate name of Arad, Iran, a city in Fars Province...
, video camera
Video camera
A video camera is a camera used for electronic motion picture acquisition, initially developed by the television industry but now common in other applications as well. The earliest video cameras were those of John Logie Baird, based on the electromechanical Nipkow disk and used by the BBC in...
, VCR, or DVD player
DVD player
A DVD player is a device that plays discs produced under both the DVD-Video and DVD-Audio technical standards, two different and incompatible standards. These devices were invented in 1997 and continue to thrive...
. It may or may not have professional audio
Professional audio
Professional audio, also 'pro audio', refers to both an activity and a type of audio equipment. Typically it encompasses the production or reproduction of sound for an audience, by individuals who do such work as an occupation like live event support, using sound reinforcement systems designed for...
monitoring capability. Unlike a television set
Television set
A television set is a device that combines a tuner, display, and speakers for the purpose of viewing television. Television sets became a popular consumer product after the Second World War, using vacuum tubes and cathode ray tube displays...
, a video monitor has no tuner (television) and, as such, is unable independently to tune into an over-the-air
Over-the-air
Over-the-air has several meanings, depending on context. *Generally, over-the-air is synonymous for wireless.*Specifically, over-the-air can have the following meanings or is used in the following contexts:...
broadcast like a television receiver. One common use of video monitors is in television station
Television station
A television station is a business, organisation or other such as an amateur television operator that transmits content over terrestrial television. A television transmission can be by analog television signals or, more recently, by digital television. Broadcast television systems standards are...
s, television studio
Television studio
A television studio is an installation in which a video productions take place, either for the recording of live television to video tape, or for the acquisition of raw footage for post-production. The design of a studio is similar to, and derived from, movie studios, with a few amendments for the...
s, production truck
Production truck
Television Production trucks were developed to take television studios on the road so video productions could be made at distant locations for a remote broadcast, outside broadcasting , electronic field production with multiple-camera setup and a support of a number of different technologies to...
s and in outside broadcast vehicles, where broadcast engineers use them for confidence checking of analog signal
Analog signal
An analog or analogue signal is any continuous signal for which the time varying feature of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal. It differs from a digital signal in terms of small fluctuations in the signal which are...
and digital signal
Digital signal
A digital signal is a physical signal that is a representation of a sequence of discrete values , for example of an arbitrary bit stream, or of a digitized analog signal...
s throughout the system.
Video monitor
Video monitor
A video monitor also called a broadcast monitor, broadcast reference monitor or just reference monitor, is a display device similar to a television set, used to monitor the output of a video-generating device, such as playout from a video server, IRD, video camera, VCR, or DVD player. It may or...
s are used extensively in the security industry with closed-circuit television camera
Closed-circuit television camera
Closed-circuit television cameras can produce images or recordings for surveillance purposes, and can be either video cameras, or digital stills cameras...
s (CCTV) and recording devices.
Common display types for video monitors
- Cathode ray tubeCathode ray tubeThe cathode ray tube is a vacuum tube containing an electron gun and a fluorescent screen used to view images. It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. The image may represent electrical waveforms , pictures , radar targets and...
- Liquid crystal displayLiquid crystal displayA liquid crystal display is a flat panel display, electronic visual display, or video display that uses the light modulating properties of liquid crystals . LCs do not emit light directly....
- Plasma displayPlasma displayA plasma display panel is a type of flat panel display common to large TV displays or larger. They are called "plasma" displays because the technology utilizes small cells containing electrically charged ionized gases, or what are in essence chambers more commonly known as fluorescent...
Common monitoring formats for security
- Composite videoComposite videoComposite video is the format of an analog television signal before it is combined with a sound signal and modulated onto an RF carrier. In contrast to component video it contains all required video information, including colors in a single line-level signal...
- S-VideoS-VideoSeparate Video, more commonly known as S-Video and Y/C, is often referred to by JVC as both an S-VHS connector and as Super Video. It is an analog video transmission scheme, in which video information is encoded on two channels: luma and chroma...
Broadcast reference monitor
Broadcast reference monitors must be used for video complianceCompliance
Compliance can mean:*In mechanical science, the inverse of stiffness*Compliance , a patient's adherence to a recommended course of treatment...
at television or television studio
Television studio
A television studio is an installation in which a video productions take place, either for the recording of live television to video tape, or for the acquisition of raw footage for post-production. The design of a studio is similar to, and derived from, movie studios, with a few amendments for the...
facilities, because they do not perform any video enhancements and try to produce as accurate an image as possible.
For quality control purposes, it is necessary for a broadcast reference monitor to produce (reasonably) consistent images from facility to facility, to reveal any flaws in the material, and also not to introduce any image artifacts (such as aliasing
Aliasing
In signal processing and related disciplines, aliasing refers to an effect that causes different signals to become indistinguishable when sampled...
) that is not in the source material. Broadcast monitors will try to avoid post processing such as a video scaler
Video scaler
A video scaler is a device for converting video signals from one size or resolution to another: usually "upscaling" or "upconverting" a video signal from a low resolution to one of higher resolution A video scaler is a device for converting video signals from one size or resolution to another:...
, line doubling and any image enhancements such as dynamic contrast. However, display technologies with fixed pixel structures (e.g. LCD, plasma) must perform image scaling when displaying SD signals as the signal contains non-square pixels while the display has square pixels. LCDs and plasmas are also inherently progressive displays and may need to perform deinterlacing
Deinterlacing
Deinterlacing is the process of converting interlaced video, such as common analog television signals or 1080i format HDTV signals, into a non-interlaced form....
on interlaced video signals.
Some Professional video broadcast monitors display information on screen, the current video signal format, they might be receiving i.e.: standard definition formats like 576i
576i
576i is a standard-definition video mode used in PAL and SECAM countries. In digital applications it is usually referred to as "576i", in analogue contexts it is often quoted as "625 lines"...
, 480i
480i
480i is the shorthand name for a video mode, namely the US NTSC television system or digital television systems with the same characteristics. The i, which is sometimes uppercase, stands for interlaced, the 480 for a vertical frame resolution of 480 lines containing picture information; while NTSC...
or high definition
High-definition video
High-definition video or HD video refers to any video system of higher resolution than standard-definition video, and most commonly involves display resolutions of 1,280×720 pixels or 1,920×1,080 pixels...
formats like 720p
720p
720p is the shorthand name for 1280x720, a category of High-definition television video modes having a resolution of 1080 or 720p and a progressive scan...
or 1080p
1080p
1080p is the shorthand identification for a set of HDTV high-definition video modes that are characterized by 1080 horizontal lines of resolution and progressive scan, meaning the image is not interlaced as is the case with the 1080i display standard....
. They also have mechanical buttons to toggle
Toggle
Toggle may refer to:*Toggle mechanism*Toggle switch*Toggling harpoon*A type of textile closure, like an elongated button*Toggle , a character in the comic strip Doonesbury...
common aspect ratios like (4:3 or 16:9
16:9
16:9 is an aspect ratio with a width of 16 units and height of 9. Since 2009, it has become the most common aspect ratio for sold televisions and computer monitors and is also the international standard format of HDTV, Full HD, non-HD digital television and analog widescreen television ...
), and underscanning or overscan
Overscan
Overscan is extra image area around the four edges of a video image that may not be seen reliably by the viewer. It exists because television sets in the 1930s through 1970s were highly variable in how the video image was framed within the cathode ray tube .-Origins of overscan:Early televisions...
ning a picture to see lines in the vertical blanking interval
Vertical blanking interval
The vertical blanking interval , also known as the vertical interval or VBLANK, is the time difference between the last line of one frame or field of a raster display, and the beginning of the first line of the next frame. It is present in analog television, VGA, DVI and other signals. During the...
(VBI) of video, and check if subtitles in VBI were inserted properly or not. Modern broadcast grade professional monitors also have safe area
Safe area
Safe area is a term used in television production to describe the areas of the television picture that can be seen on television screens.Older televisions can display less of the space outside of the safe area than ones made more recently...
grid generators, to help position television
Television
Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
graphics, lower thirds
Lower thirds
In the television industry , a lower third is a graphic placed in the title safe lower area of the screen, though not necessarily the entire lower third of it, as the name suggests....
, within their respective areas i.e. graphics safe, title safe or action safe.
Common monitoring formats for broadcasters
- Component videoComponent videoComponent video is a video signal that has been split into two or more component channels. In popular use, it refers to a type of component analog video information that is transmitted or stored as three separate signals...
- Composite videoComposite videoComposite video is the format of an analog television signal before it is combined with a sound signal and modulated onto an RF carrier. In contrast to component video it contains all required video information, including colors in a single line-level signal...
- Serial Digital InterfaceSerial Digital InterfaceSerial digital interface is a family of video interfaces standardized by SMPTE. For example, ITU-R BT.656 and SMPTE 259M define digital video interfaces used for broadcast-grade video...
(SDI, as SD-SDI or HD-SDI)
Features
Professional Video monitors have various features that consumer monitors lack such as:- Conforms to colorimetryColorimetryColorimetry is "the science and technology used to quantify and describe physically the human color perception."It is similar to spectrophotometry, but is distinguished by its interest in reducing spectra to the physical correlates of color perception, most often the CIE 1931 XYZ color space...
standards such as the SMPTESociety of Motion Picture and Television EngineersThe Society of Motion Picture and Television Engineers The Society of Motion Picture and Television Engineers The Society of Motion Picture and Television Engineers (SMPTE , founded in 1916 as the Society of Motion Picture Engineers or SMPE, is an international professional association, based in...
C, Rec. 709Rec. 709ITU-R Recommendation BT.709, more commonly known by the abbreviations Rec. 709 or BT.709, standardizes the format of high-definition television, having 16:9 aspect ratio. The first edition of the standard was approved in 1990....
, or EBU primaries. - SDISerial Digital InterfaceSerial digital interface is a family of video interfaces standardized by SMPTE. For example, ITU-R BT.656 and SMPTE 259M define digital video interfaces used for broadcast-grade video...
inputs / outputs. - AES/EBUAES/EBUAES3 is the standard used for the transport of digital audio signals between professional audio devices. It is also known as AES/EBU and is published by the Audio Engineering Society and as part of IEC 60958. It was developed by the AES and the European Broadcasting Union and first published in...
Audio decoding. - GenlockGenlockGenlock is a common technique where the video output of one source, or a specific reference signal from a signal generator, is used to synchronize other television picture sources together. The aim in video and digital audio applications is to ensure the coincidence of signals in time at a...
input. - GPI interface - For receiving external triggers.
- Modular expansion card slots that support SD-SDISMPTE 259MSMPTE 259M is a standard published by SMPTE which "... describes a 10-bit serial digital interface operating at 143/270/360 Mb/s." The goal of SMPTE 259M is to define a Serial Digital Interface , called SDI or SD-SDI....
or HD-SDISMPTE 292MSMPTE 292M is a standard published by SMPTE which expands upon SMPTE 259M and SMPTE 344M allowing for bit-rates of 1.485 Gbit/s, and 1.485/1.001 Gbit/s...
single link or dual-link HD-SDISMPTE 372MSMPTE 372M is a standard published by SMPTE which expands upon SMPTE 259M, SMPTE 344M, and SMPTE 292M allowing for bit-rates of 2.970 Gbit/s, and 2.970/1.001 Gbit/s over two wires. These bit-rates are sufficient for 1080p video....
cards. - Safe areaSafe areaSafe area is a term used in television production to describe the areas of the television picture that can be seen on television screens.Older televisions can display less of the space outside of the safe area than ones made more recently...
cage. - Rack19-inch rackA 19-inch rack is a standardized frame or enclosure for mounting multiple equipment modules. Each module has a front panel that is wide, including edges or ears that protrude on each side which allow the module to be fastened to the rack frame with screws.-Overview and history:Equipment designed...
mountable.