As video compression technology improvement and development of computer technology, video server has been widely used in the television broadcast system, video server in the comprehensive application of channel system, make the broadcast system is one of the most important part of a product, which can greatly improve the efficiency of the television. Actually, the video server still has many traditional video equipment possesses the advantages, also can develop many new applications.

A video server, concept

Video server is a visual audio data compression, storage and handling of special computer equipment, it in spots, multi-channel circular pad, delay, hard disk video broadcast and broadcast on demand, etc are widely used. Video server using M -- -- such as JPEG compression or MPEG format, in 2 cases with technical indicators of video data compression coding, storage and transmission to meet the requirements. It USES SCSI hard disk or interface FC interface as audio data online storage. Has the multichannel input/output, various audio formats interface. Can be equipped with SCSI, FC in networking, network interfaces as realization audio data transmission and sharing.

Second, video server

Video server is a kind of compression, storage and handling of special computer audio and video data, it consists of audio and video compression encoder, large

Amount storage device, input/output channel, the network interface, audio interface, RS422 interface, serial interface, agreement, software interface

Audio intersection matrix, etc, and provide the lock and video processing function.

Audio compression encoder: because after video digitizing, because of the large amount of data, and to use the mature technology, video data compression

In the technical indexes meet the requirements under the condition of high compression ratio compression, storage and transmission requirements. Video server generally USES M

-- -- such as JPEG compression or MPEG encoder, 2 according to the actual situation of the users can choose compression rate and compression, suitable for all kinds of no

On the occasion, with both save disk space, increase program storage, and can ensure the quality of air.

Mass storage device: video server using high-speed broadband interface, the SCSI hard disk or the most advanced FC disk as visual interface

Frequency material storage media. While audio data disk expansion is flexible.

Input/output channels: video server has multichannel input/output system, make multiple entry, broadcast can simultaneously, realize

Multiple tasks.

Network video server interface: all with network interface, easy, realize the sharing data networking. General video server with FC

And the Ethernet interface. FC fiber network using IP video server as fast, real-time copy and between the exchange network, moving material

Ethernet is used to transfer data and control of detecting state information.

Audio video server interface: all standard audio interface with video surveillance, and to monitor the interface video channel

Signal. Input/output signal can be simulated, and select SDI.

RS422 serial interface: video server with multiple RS422 interface, serial communication each interface can be passed RS422 communications lines

Computer controlled by external record and playback.

In video server protocol interfaces: provide various control hardware interface, protocol interfaces. If RS422 interface besides support

RS422 Profile of the agreement, also support Louth, Odetics BVW, such agreement by RS422 control.

Video server software interface: provide open-source software interface, user or third-party vendors development and construct new application.

Audio video server intersection matrix: in visual and audio, visual and audio intersection matrix, and flexible operation channel can be guaranteed

Card technology index is not damaged.

In addition, video server provides the video processing functions, lock and convenient construction of professional audio system application.

Third, video server features

Video server with traditional equipment has many characteristics, specific as follows:

(1) will be recorded and broadcast channels, such functions of traditional equipment, have multiple input and output devices are characteristics

Audio switching matrix, and has the function of recording and playback of equipment is self-evident, video server VCR, if can replace in the system

Do a video and a small switching matrix.

(2) video server disk recording media, as the non-linear characteristics, thus has the advantages of nonlinear equipment all,

If material lookup conveniently, Material can be Shared by multiple output channel, One can also play out or.

(3) in the disk material records yet, forming a complete documents by the output channel, which broadcast out very applicable to delay

Video vod broadcast and etc.

(4) video server easier to achieve forward or backward traditional video broadcast transmission, to realize this, should pass the price

Expensive stunt equipment.

Four, video server application in television

Due to the video server has the advantage, therefore it will create many innovative application in order to meet the needs of TV media,

And can greatly improve productivity and reduce maintenance and manpower cost. Video server in the application fields of television has two main aspects

Using video server: one is building broadcast system, Video server is realized using video ordering.

1. Use video server construct broadcast system

Previous broadcast system based on magnetic tape for major media video compression technology, but with the improvement and development of computer technology,

In video broadcast system using server has become may also has many TV in China, established in use today is broadcast

When the video server ec choose as a signal has become inevitable. In video server disk broadcast system as the main body, full

The hard disk drive storage swing, avoids video equipment malfunction to broadcast the impact of multi-channel, give full play to the resource sharing

Each program, easily between broadcast and various commercial alligator, broadcast, to control and management of the zip-file shape

The program of hard disk, in can achieve without distortion from all programs, create, edit, thus simplifying the port upload from the system

Do the work flow, to broadcast to improve work efficiency.

The hard disk broadcast systems, programming material is compressed digital broadcast and stored. System can adopt the MPEG - 2 or M - JPEG

Compressed format. Hard disk broadcast system can adopt local storage, mirror backup of disk storage RAID. Also known as 1 - RAID

"Mirror image", namely, adopt double disc completely copy method to protect data, to avoid the hard disk failure data loss and system, its

The redundancy can achieve 100% recovery of data. Each video server disk storage is independent of the local store, the video

Server noninterference, between the mirror backup system, high reliability.

Hard disk broadcast system can be used in combination with Ethernet FC double net structure, use audio signal transmission, FC with Ethernet transmission control

Signal.

Hard disk broadcast system consists of audio and video server, database server, collecting workstation, workstations, broadcast stations DengZi prison

Series. Two audio data backup servers. Server through the optical fiber network interconnection. The server of audio materials through the optical fiber

Nets to complement the server. By a set of automatic control system of two broadcast on the server audio workstation are broadcast simultaneously. this

Sample system is very reliable. At the same time, the system according to the different user setting different security levels, can not enter the system; unauthorized persons. have

To ensure the validity of safety, system data broadcast system, automatic locking various other illegal operation, timely warning signal

.

In video server for the hard disk broadcast system of the specific application way has the following kinds:

(1) automatic broadcast advertisement

Video server first used in the replay number, time is short of commercials. In this way, the video server application in a wide

Against the special equipment, it is controlled by broadcast system of automatic control by video server software, undertake according to order a broadcast only

A, advertising materials by advertisement on computer control, editor of the order of broadcast advertisement layout and control by advertising

A computer is responsible for, and the starting point and end aired by automatic computer implementation of broadcast control computer control of ads. this

Application without the need for the broadcast system has changed greatly, the original seeding of the automatic control system and the software can continue to use, video

Server here more video tape recorder (depending on the equivalent of the input video server) and more FangXiangJi (depending on the video

The server output channel number). Therefore the original seeding of the automatic control system software can like VCR video server control as control

Do advertisement.

(2) much channel broadcast system

Using video server multi-channel characteristics can build cycle mat, multiple channel broadcast system of common room. Broadcast In this application

In each of the first channel broadcast material through the VTR + entry MATS, video server to each room occupied video channel

Service of one output channel, video server can broadcast every material. In this way, can use a application configuration

The same video server broadcast system. Lord, video server for the use of one output channel, as mutual backup

The broadcast channels, main, prepare video server between the fibre nets (fc-san) Internet, audio and video footage sharing, mobile and copy,

Ensure the video footage of the server, prepared. By a set of automatic control system of two broadcast video broadcast stations in the server

Line.

(3) TV broadcast system. Delay

Using video server TV broadcast system using video is the delay in the server, hard disk, written material

Need not fully formed a material document circumstance, can be Shared disk broadcast system, make calls have recorded so-called namely is sowing (to slightly

After a delay before the function can be broadcast). This scheme is suitable for the live broadcast important programs. Will live broadcast first entry hard disk, as required

To be broadcast live broadcast time delay appropriate director and the attendant use this time playing computer control rate adjustment

On the field of broadcast is suitable for cutting and other material, or in the eye to distinguish rate, such as 0.8-120

Times as fast or slow play, in order to maintain the corresponding late. On the basis of advanced techniques, improper control can dodge

The broadcast, broadcast effect and has no effect.

Using video server disk broadcast system and a variety of specific application, here no longer list on the comparison

Traditional video broadcast, hard disk broadcast system of the signal and material is not exist, so YouLing frame cartridges, nonlinear beforehand

Retrieval and material use repeatedly, sharing resources, etc. Specific advantages are: to improve work efficiency and better security, information

A sharing of resources and the progressiveness of system.

2 use video server realize video ordering

There are two ways to video VOD VOD video: namely NVOD (VOD) and video (VOD)

(1) must video ordering (NVOD)

Video server is realizing prospective video vod broadcast NVOD () the core equipment, using its multi-channel characteristics and material can be Shared

Implement a program, a time interval, viewing the replay in shortest time watching vod himself for the program. Such as: in the video

Within a length of time for server program, the N eight output channel output, the second passage were relatively the first channel delay N / 8

A third time, relative to the second passage channel 8 time delay N/play, and so on. Each channel programs that looping

Yao played the first channel next time relative eighth channel is broadcast time delay N / 8. Such adjacent channel broadcast

Is the same programs, but time interval is N / 8. User demand, the demand information via computer programs, after treatment for broadcast programs

Put the control computer will immediately to broadcast channels, such information to users to authorized users receive equipment in N / 8 hours can see

To their demand.

(2) video ordering (VOD)

Video server can be used not only in quasi video VOD system, also can used for video ordering (VOD) system. VOD Video called the whole

Video On Demand, vod technology, also known as interactive TV vod system, according to the need of the video playback. "Want to see

Want to see the syndrome "show, the user can choose according to their television, fundamentally change the passive

TV, fully realized by users grasp the initiative to obtain information. Still can realize the Internet, VOD E-mail

Shopping, family, travel, booking tickets booking, stock trading and other functions. Therefore say, this technology enables a user

According to their needs to arrange jobs and entertainment time, really realized by users grasp the initiative, greatly improving ratings and improved

The quality of people's lives and work efficiency.

VOD system by head-end system, network system and customer system, which is composed of three parts by video server front-end system of general and various

Archives management server and network equipment of controlling part. Some of the main server user archives information management and billing

Work, as well as the film materials management and security and confidentiality, etc. The main parts of control network server in various information

Pass the film and background materials and data exchange. Video server consists mainly of storage systems and establish its various controller management

System, and its goal is to realize the compression of the data storage media and press the request for the retrieval and media information transmission. Video server

With the traditional data servers significantly different in many ways, need to solve many problems, to support various new functions. At the same time, it

High-speed data transmission ability of a film that a user program, video, game, business information and other service near instantaneous

Q. It is the biggest characteristic is to realize people from different starting point to watch the same programs, to avoid a wonderful program is a user monopoly

.

This application scope is big, must be more video server components of multi-channel can share the large capacity hard disk storage and can handle

Transmission flow of broadband network, can satisfy all sorts of numerous users demand for program needs. User demand information can have two paths to

Vod accepts the server: one kind is through the city of catv HFC network vod accepts the uplink channel to the server. Another kind is

Through the general browser on the Internet for the program will choose, vod vod accepts the message to the server. Vod accepts the server

Relevant information processing, to play computer control, by its users of vod broadcast programs, and through HFC downlink channels

To user terminals. Users receive has two kinds: one kind is ordinary TV + STB, another kind is receiving card, using computer +

The computer display.

Based on the video server multi-channel digital broadcast system based on video tapes with traditional broadcast system simulation is incomparable

Many advantages, video server hardware platform and the open standards or common interface protocols, strong ability to expand, and

The future of digital and networked, multi-channel and mode of resource sharing program broadcast system, create, edit and connected. Dish of

Based on the combination of video taping or server multi-channel digital broadcast system can realize error isolation and fault isolation broadcast, also can achieve

Broadcast TV, delay transition from analog to digital broadcast the best solution. But in the long run, video vod has great potential

In the market and the development prospect profoundly, because from deep, VOD VOD video program is not the problem, it represents the future

Function of network and application of digital interactive information, is a development trend of content, form from deeper interactions, and count

Word cinemas, interactive video news, advertising and other new applications, the foundation has wide development potential, VOD is the information superhighway

The plane is an important part of the information service of the soul of broadband. So be sure, along with the digital technology, multimedia technology

With the development of computer technology, video server on TV the application fields will have more outspread.

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