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9 ask digital video light upright chance
From;    Author:Stand originally



Ask 4: What is PCM encode

PCM (arteries and veins piles up modulation Pulse Code Modulation) . It is a kind of sampling technology that digitlizes to imitate signal, basically include to sampling is quantified and code 3 processes. Sampling is a time successive imitate signal is changed into the sampling signal with time disperse successive extent; Quantifying is the digital signal that changes the sampling signal with time disperse successive extent into disperse of time disperse extent; Encode is to will quantify the signal encode after to form output of group of a binary code. OT Systems light carries product of machine the whole line to be 10 PCM encode. ? ?


Ask 5: What is video bandwidth

Video bandwidth is video the very main index in transmitting. The bandwidth of smooth end chance is like the driveway of highway, driveway can appear not quite traffic jam phenomenon, create traffic block, bandwidth is insufficient, picture detail part is not quite clear, horizontal resolution is low, appeared even lack fidelity or colour is missing. Groovy video bandwidth is in 8M above, the demand is a few lower also should be in 6.5M above. For chance of smooth to the number end, video bandwidth basically is the sampling frequency that points to digitlization. Frequency of sampling of smooth end chance is taller, processing and transmission data bulk are greater, the cost of smooth end chance is higher. If the user uses definition to compare tall camera, can differentiate with the eye different bussiness trip. Chance of end of OT Systems light is 16M sampling frequency, can offer 8M video bandwidth. In bandwidth the bring to sb's attention of the everybody in this index, the video bandwidth of intended exaggerated product cheats very much illegal manufacturer client, the multichannel number video that some manufacturer produces is smooth upright machine alleges its video bandwidth is 8M, but the video sampling frequency that its announce external is 12.5M. According to Nai Kui this special sampling is mensurable, want bona fide reductive signal, double its sampling frequency should be signal frequency at least. Calculate so come, its inspect the smooth end chance of this manufacturer theoretically frequency bandwidth exceeds 6.25M impossibly also anyhow. Apparent, this is the crammer of client of deceit of an exaggerated function, the manufacturer that does not have commercial reputation so should be not put in the consideration limits of choose and buy. But not all client can accurate identifying the crammer of the manufacturer, proposal project business and user had better be the detail that observes image, the definition that carries image judges the video bandwidth of equipment roughly.


Ask 6: What is APL limits enough wide
Namely picture is average n, a lot of project business are familiar with this index not quite. But, if respecting project is medium,encounter so one resembles now: Video signal is transmitted through smooth end chance, when the white that there should be large area in the picture (when be being shot by strong illumination like camera) the picture on monitor shakes with respect to meeting level, so engineering personnel scarcely is unfamiliar. The APL range of the engine of video light end that this produces because of some manufacturers namely is too narrow, when there is large area white in picture signal, the dc heft in every picture signal increases, APL will lift, cause a synchronous signal to extent is reduced or be lost thereby, monitor cannot detect produce picture flutter to travel synchronism.
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