| Currently, most of video recorders in China are still the broadcast video recorders whichwere produced in the1980s or1990s. The General video bandwidth is at5MHz, used acomponent video signal to divide analog signals into three-way-Y, U, V. Here Y represents thebrightness, U, V represent the chromatic aberration. According to the three wires, video taperecorder transmits and records information in analog tape three roads on magnetic mark. Due tothe high cost of maintenance and expensive price of this kind of tape to record the data, VTRneeds improving and modifying. The content of the article will emphasize on the research anddevelopment process which are based on SATA hard disk (DVR).The cost of storage will reduce by90%, if SATA hard disk instead of the traditional tape, andthe video recording way changed into RGBA（U88-channel analog signals）of the JPEG, andeven into RGBA (U1616-channel analog signals). Through the u8or u16which transmits theRGBA and their gamma data to SATA hard disk, DVR will receive wider bandwidth and higherquality, more accurate color replay, and more vivid human visual.The system of Digital Video Recorder (DVR) is topic of this paper. The topics are based onwavelet compression technology and cross-compiler technology. Using it, we can get maximumextent possible to restore the video images, and in noise reduction, can maintain the energy of thegraphics by deleting the form of the upper and lower limits. With the rapid development ofcomputer technology, especially in digital transmission and digital compression technology,DVR technology indicators are fully satisfied with the needs of radio and television recordingprogram. Thus DVR had gained its share because of its convenient features, and will eventuallyphase out VTR.Compared with the VTR, DVR has the following advantages:1. Avoided Linear edit mode of VTR, DVR uses the non-linear editing and recording way, sothat brings facilitation and convenience to people to operate the post editing and production.2. Using a digital storage format, people can easily deal with data to improve the reductiondegrees of the signal and to guarantee the quality which is still consistent with the original videodata after repeatedly playback. Through SATA hard drive, video data can get long-termpreservation and playback without the bad affection to the video data quality. 3. DVR can help to reduce VTR’s shortcomings which are always failed in the physicaldevice.DVR broadcast system can be divided into two stages which are the Independent andnetwork stage:1. Independent stage of DVRThe independent stage usually adopts automatic broadcast system. For the voice frequency,people use88.2kHz of sampling frequency,32single-frequency output signal, and90dB noiseratio of CD quality under the standard of CCIR712. For the video signal, they use16bitprocessing way,6.0MHz bandwidth, and80dB SNR. This DVR is primarily used in advertisingstring Code, to store a large number of advertising programs by re-use of non-linear way ofstorage on the hard drive. By the main computer Dynamic control system, People can controlthrough the remote control interface broadcast. As the early hard disk video recorder, the systemis simple, affordable. With the traditional mode of operation, the recorder has been widely used,and thus used in ad string knitting. However, the non-linear string editing system is a generallack of a digital interface, and left the inconvenience for the future to update and development ofnetworks and all-digital.2. Network stage of DVRIn order to treat the video server as dominant, Network stage of DVR with automaticallybroadcast system uses a multichannel parallel hard disk video technology. Through theadvertising department of the local area network video servers and fiber, Sub-control systemswill connect advertising sector with other sectors (the network using the protocol of TCP/IP).The Sub-control systems through the network server, send the video data to the total serverthrough a digital network to implement the interaction of multiple functional departments(advertising, news, etc.), to achieve multi-port input and output and sharing of informationresources. This structure is widely used in the ad. Multi-channel DRV system has a very distinctadvantage in this regard; Making process reduced to the minimum and greatly enhancingfunctionality and flexibility and Just putting video data entry in the database, the variousdepartments will feel convenient to operate the video processing after the recording. It is alsoconvenient to modify the Video data on a Personal Computer, and to change the order of playing.The main function of the realization of the system is to compress the code sent bymulti-channel high quality Video and audio in DM6467T application in image processing chipindependently. Digital images will be compiled in a coded form stored in the SATA hard drive.Stored image coding with panel or remote control, can be displayed or playbacked on displayer or Broadcast frequency way. This system can meet the needs of large data storage capacity,frequent backups of data, quick and easy retrieval, backup, and playback, delete the hard drivedata. |
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