VOD is video on demand Video On Demand, was the recent years emergingmedia way, this technology was the computer technology, the networkcommunication, multimedia technical, the television technology and thedigital compression technology and so on multi-disciplinary, themulti- domains fusion overlapping union product. The VOD technologyenables the people to be allowed to act according to own interest,does not use with the aid of the videorecorder, the video compact diskmachine, the cable TV but on the computer or the television freely inthe selection and broadcast program storehouse video frequency programand the information, is may carry on the free choice to the videofrequency program content the interactive system, was variouscountries software researches and develops the personnel in recentyears the key research application domain.
The VOD essence is the information user acts according to own demandto obtain the multimedia
information on own initiative, itdistinguishes greatly differently between the information issue
most:One is the initiative, two is the selectivity. From some kind ofsignificance said this is the
information receiver carries on theself-perfection and the self- development way according to own
need,this way more and more will conform to the information resourceconsumer's in-depth need in the now
information society, will beallowed to say V O D will be the information acquisition futuremainstream
way in multimedia regards the audio frequency aspect theperformance. The VOD concept will be able in
the informationacquisition domain fast expansion, to have the infinite broadprospects for development.
The VOD system by the video frequency server, the correspondencenetwork, the customer end equipment, the manufacture management systemmanagement system and so on four major part is composed.
1) video frequency server: Massive memories video frequency programinformation; Processing user's interactive order informationtransmission video frequency data
2) corresponds the network: Branch net: Requests a higher band width,the connection video frequency server and the manufacture managementsystem management system sub- net: As branch net next level ofnetworks, information transmission each customer end equipment.
3) customer end equipment: Completes the video frequency programinformation automatic broadcast; Provides the user the simpleoperation contact surface, receives the interactive order information.
4) manufactures the management system management system: Completes thevideo frequency program the edition and the manufacture; Videofrequency image storehouse management, video frequency databasemanagement; VOD system user's management; Account service management.
VOD system model application domain: The video on demand system maywidely apply to the computer local area network, WAN, the wide bandsynthesis turns on the net, the wired television network and so on,all has the broad application prospect in many domains.
1) KTV nobody engine room entire automatic computer song, film andtelevision song selection and
broadcast, Kara OK singsong housecomputer selection and broadcast, wired television station
telephonepronunciation selection and broadcast
2) multi-purpose internet bar
3) campus net multimedia classroom
4) multimedia library, multimedia information issue, electroniclibrary, government enterprise
5) interacts the type survey demonstration system
6) interactive multimedia demonstration that, Airport, trainstation, theater exhibition hall, museum advertising industry market,guesthouse, department store
7) hotels guest room computer automatic selection andbroadcast, on international interconnecting
8) residential district
9) enterprise interior training 10) educates and training, the long-distance teaching, thehospital
pathology analysis and the long-distance medical service(diagnosis)