Video server
Encyclopedia
A video server is a computer based device (also called a 'host') dedicated to delivering video.
Unlike personal computer
s, 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 video streams without any degradation of the video signal. Broadcast quality
video servers often store hundreds of hours of compressed audio and video (in different codecs), play out multiple and synchronised simultaneous streams of video by, and offer quality interfaces such as SDI
for digital video and XLR for balanced analog audio, AES/EBU
digital audio and also Time Code
. A genlock
input is usually provided to provide a means of synchronizing with the house reference clock, thereby avoiding the need for timebase correction
or Frame synchronizers.
Video servers usually offer some type of control interface allowing them to be driven by broadcast automation
systems that incorporate sophisticated broadcast programming applications. Popular protocols include VDCP and the 9-Pin Protocol
.
They can optionally allow direct to disk recording
using the same codec
that is used in various post-production
video editing software
packages to prevent any wasted time in transcoding.
industry, a server is a device used to store broadcast quality images and allows several users to edit stories using the images they contain simultaneously.
The video server can be used in a number of contexts, some of which include:
Generally, they have several bi directional channels (record and ingest) for video and audio. A perfect synchronisation is necessary between those channels to manage the feeds.
video streams. The IP video server can stream digitized video over IP networks in the same way that an IP Camera
can. Because an IP Video server uses IP protocols, it can stream video over any network that IP can use, including via a modem for access over a phone or ISDN connection. With the use of a video server attached to an analog camera, the video from an existing surveillance system
can be converted and networked into a new IP surveillance system.
In the video security industry a video server is a device to which one or more video sources can be attached. Video servers are used to give existing analog systems network connectivity. Video servers are essentially transmission/ telemetry / monitoring devices. Viewing is done using a web browser or in some cases supplied software. These products also allow the upload of images to the internet or direct viewing from the internet. In order to upload to the internet an account with an ISP
(internet service provider) may be required.
Unlike personal computer
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
s, being multi-application devices, a video server
Server (computing)
In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients"...
is designed for one purpose; provisioning video, often for broadcasters
Broadcasting
Broadcasting is the distribution of audio and video content to a dispersed audience via any audio visual medium. Receiving parties may include the general public or a relatively large subset of thereof...
. A professional grade video server records, stores, and 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...
of multiple video streams without any degradation of the video signal. Broadcast quality
Broadcast quality
Broadcast Quality is an term stemming from quad videotape to denote the quality achieved by professional video cameras and time base correctors used for broadcast television, usually in standard definition...
video servers often store hundreds of hours of compressed audio and video (in different codecs), play out multiple and synchronised simultaneous streams of video by, and offer quality interfaces such as SDI
Serial Digital Interface
Serial 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...
for digital video and XLR for balanced analog audio, AES/EBU
AES/EBU
AES3 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...
digital audio and also Time Code
Time code
A timecode is a sequence of numeric codes generated at regular intervals by a timing system.- Video and film timecode :...
. A genlock
Genlock
Genlock 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 is usually provided to provide a means of synchronizing with the house reference clock, thereby avoiding the need for timebase correction
Timebase correction
Time base correction is a technique to reduce or eliminate errors caused by mechanical instability present in analog recordings on mechanical media. Without time base correction, a signal from a videotape recorder or videocassette recorder cannot be mixed with other, more time stable devices...
or Frame synchronizers.
Video servers usually offer some type of control interface allowing them to be driven by broadcast automation
Broadcast automation
Broadcast automation incorporates the use of broadcast programming technology to automate broadcasting operations. Used either at a broadcast network, radio station or a television station, it can run a facility in the absence of a human operator...
systems that incorporate sophisticated broadcast programming applications. Popular protocols include VDCP and the 9-Pin Protocol
9-Pin Protocol
The 9-Pin Protocol is a two-way communications protocol for the RS-422 D-sub electrical connector interface, in which a bi-direction signal is transmitted over a single, four wire, serial cable to allow the remote control of a wide variety of devices including, reel-to-reel type C videotape video...
.
They can optionally allow direct to disk recording
Direct to Disk Recording
Direct-to-disk recording refers to methods by which analog signals and digital signals such as digital audio and digital video are digitally recorded to optical disc recording technologies such as DVDs, and CD optical discs...
using the same codec
Codec
A codec is a device or computer program capable of encoding or decoding a digital data stream or signal. The word codec is a portmanteau of "compressor-decompressor" or, more commonly, "coder-decoder"...
that is used in various post-production
Post-production
Post-production is part of filmmaking and the video production process. It occurs in the making of motion pictures, television programs, radio programs, advertising, audio recordings, photography, and digital art...
video editing software
Video editing software
Video editing software, is application software which handles the post-production video editing of digital video sequences on a computer non-linear editing systems...
packages to prevent any wasted time in transcoding.
Broadcast automation
In the TV broadcastBroadcast
Broadcast or Broadcasting may refer to:* Broadcasting, the transmission of audio and video signals* Broadcast, an individual television program or radio program* Broadcast , an English electronic music band...
industry, a server is a device used to store broadcast quality images and allows several users to edit stories using the images they contain simultaneously.
The video server can be used in a number of contexts, some of which include:
- News: providing short news video clips as part of a news broadcast as seen on networks (like CNNCNNCable News Network is a U.S. cable news channel founded in 1980 by Ted Turner. Upon its launch, CNN was the first channel to provide 24-hour television news coverage, and the first all-news television channel in the United States...
and Fox News). - Production: enhance live events with instant replays and slow motionSlow motionSlow motion is an effect in film-making whereby time appears to be slowed down. It was invented by the Austrian priest August Musger....
and highlights (sport production) (see OB VansOutside broadcastingOutside broadcasting is the electronic field production of television or radio programmes from a mobile remote broadcast television studio. Professional video camera and microphone signals come into the production truck for processing, recording and possibly transmission...
) - Instruction: delivering course material in video format.
- Public Access: delivering city specific information to residents over a cable system.
- Surveillance: deliver real-time video images of protected sites.
- Entertainment: deliver film trailers or music videos.
Features
Typically, a video server can do the following:- Ingest of different sources : video cameras (multiple angles), satelliteSatelliteIn the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
data feedData feedData feed is a mechanism for users to receive updated data from data sources. It is commonly used by real-time applications in point-to-point settings as well as on the world-wide web. The latter is also called Web feed. News feed is a popular form of Web feed. RSS feed makes dissemination of blogs...
s, disk drives and other video servers. This can be done in different codecs. - Temporary or definitive storage of these video feeds.
- Maintain a clear structure of all stored media with appropriate metadataMetadataThe term metadata is an ambiguous term which is used for two fundamentally different concepts . Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at...
to allow fast search : name, remarks, rating, date, time codeTime codeA timecode is a sequence of numeric codes generated at regular intervals by a timing system.- Video and film timecode :...
, etc. - video editingVideo editingThe term video editing can refer to:* Linear video editing, using video tape* Non-linear editing system , using computers with video editing software* Offline editing* Online editing...
of the different clipsVideo clipVideo clips are short clips of video, usually part of a longer recording. The term is also more loosely used to mean any short video less than the length of a traditional television program.- On the Internet :... - Transfer those clipsVideo clipVideo clips are short clips of video, usually part of a longer recording. The term is also more loosely used to mean any short video less than the length of a traditional television program.- On the Internet :...
to other video servers or playoutPlayoutIn 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...
direclty (via IPInternet ProtocolThe Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...
interface or 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...
)
Generally, they have several bi directional channels (record and ingest) for video and audio. A perfect synchronisation is necessary between those channels to manage the feeds.
Video Surveillance
In the surveillance context, an IP video server converts analog video signals into IPInternet Protocol
The Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...
video streams. The IP video server can stream digitized video over IP networks in the same way that an IP Camera
IP Camera
An Internet protocol camera, or IP camera, is a type of digital video camera commonly employed for surveillance, and which unlike analog closed circuit television cameras can send and receive data via a computer network and the Internet...
can. Because an IP Video server uses IP protocols, it can stream video over any network that IP can use, including via a modem for access over a phone or ISDN connection. With the use of a video server attached to an analog camera, the video from an existing surveillance system
Closed-circuit television
Closed-circuit television is the use of video cameras to transmit a signal to a specific place, on a limited set of monitors....
can be converted and networked into a new IP surveillance system.
In the video security industry a video server is a device to which one or more video sources can be attached. Video servers are used to give existing analog systems network connectivity. Video servers are essentially transmission/ telemetry / monitoring devices. Viewing is done using a web browser or in some cases supplied software. These products also allow the upload of images to the internet or direct viewing from the internet. In order to upload to the internet an account with an ISP
Internet service provider
An Internet service provider is a company that provides access to the Internet. Access ISPs directly connect customers to the Internet using copper wires, wireless or fiber-optic connections. Hosting ISPs lease server space for smaller businesses and host other people servers...
(internet service provider) may be required.
See also
- Broadcast automationBroadcast automationBroadcast automation incorporates the use of broadcast programming technology to automate broadcasting operations. Used either at a broadcast network, radio station or a television station, it can run a facility in the absence of a human operator...
and playoutPlayoutIn 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... - CentralcastingCentralcastingIn terrestrial radio and television broadcasting, centralcasting refers to the use of systems automation by which customised signals for broadcast by multiple individual stations may be created at one central facility.- :...
- Media serverMedia ServerA media server refers either to a dedicated computer appliance or to a specialized application software, ranging from an enterprise class machine providing video on demand, to, more commonly, a small personal computer or NAS for the home, dedicated for storing various digital media .-Purpose:By...
(Consumer) - XT
[2] Xt(2)The XT[2] is a video server built and designed by the Belgian company EVS Broadcast Equipment which allows broadcasters to record, control and play media.The XT[2]+ is a newer model of the server...
video server