: the video server is a kind of visual audio data compression, storage and handling of special embedded devices, the remote monitoring and has wide application in such aspects as video.Using MPEG4 video server or MPEG2 compressed format, such as in the case of conform to the technical index of the video data compress coding, to satisfy the requirement of storage and transmission.
】 【 video server how to choose and buy video server video server buying guide,
the picture quality is the basic premise for remote monitoring, can realize remote monitoring, is the guarantee of the basic elements of unattended.There are generally two kinds of quality on the market at present the CIF and selection D1, respectively is 352 ×And 704 & 288 times;The resolution of 576.Under the condition of no account of other factors, is, of course, D1 DVD quality is the most ideal, but if consider the problem of bandwidth, CIF can cope with the demand of some ordinary occasions.
when buying the product, it is important to note must be through the Internet to see with our eyes.The same D1, some products may be more than good CIF product effect is poor, so can't on the basis of parameter, must see in person, all parameters are to serve you in the eye, must be seeing is believing.
2, different image bandwidth demand
this is one of the important indicators of measuring the overall performance of the network video server.Because of the different image state (stationary, normal activity, high speed movement), image resolution, send image frames, the network bandwidth difference is very big, so many in the network video server manufacturers recommend products, always tries to blur the index.To this, we can set up a state of relatively unified image, namely for the normal activity of image, image resolution 352 ×Number 288, frames of 25 frames per second, a video image of network bandwidth occupied.
3, IE monitoring capability
regular monitoring management software to achieve the integrity of the function, operation is cumbersome, even need special training to learn to grasp skilled.Manufacturers should provide suitable for leadership or non-professional monitoring management using a simple WEB version of the monitoring management software to choose from, to offer Internet explorer WEB form single frame image monitor, video, control and professional users do not need to install the software, monitor the image when the choice does not need to input the complex of different network video server IP address, only need access to the system of the WEB server to download a set of configuration information such as the name of point to point control, the mouse to click select the relevant image name can realize monitoring function.
to buy the product, the network environment first to see need products are used in what place, network environment?Rather than blindly to buy.If the network environment is not very good, chose the product with high requirements for network, in practice, has no practical significance.Like Benz cars crawling on the dusty mountain road, there is no room for enduring.
5, remote video transmission delay of
transmission delay of any a kind of network video server is inevitable, but different time delay value of network video server.Time delay value will directly affect the effect of digital surveillance.Therefore, to ensure that the signal of timeliness, general bandwidth without limit, for products in a microsecond.That is to say, in the absence of bandwidth limit factors, the time delay of the video server itself to ignore, so it's best to within the local area network (LAN), given enough bandwidth, test its performance.
6, front-end capture function in
under the condition of low bandwidth, transmission via FTP is high-definition pictures.Namely USES the MPEG/H series compressed format image transmission, watch and storage after compression, video have move trigger, keep out of regularity alarm trigger behavior and artificial cognizance of alarm information, instantaneous in front JPEG format high-definition capture, a very short interval, can be used as evidence in court, considering the M - JPEG and MPEG/H series two series of advantages.In the field of some monitoring, in the case of insufficient bandwidth, in order to preserve evidence, after the accident event is a good choice.
7, alarm trigger video recording
all kinds of network video server in the video on the market are fairly perfect on the function, such as real-time video, timing, video, video alarm, can be divided into the mobile video trigger, manual alarm video trigger video, external sensors (such as infrared detector) trigger video, etc.There are a few manufacturers of network video server has alarm trigger video function, can save the alarm trigger a few seconds to tens of seconds before image signal, a function for the user after the alarm event tracking judgment has a special meaning.
8, support local store
at present, with the development of video server, the application in many places require video server has the function of the local storage, ensure that under the condition of the network is not smooth, and insufficient bandwidth, save some local alarm video, provide necessary evidence for after the accident.
9, POE function at present,
"Peace throughout the city &;And "Throughout the global eye &;The project, under the propulsion of video server has been widely used., because the monitoring network, decentralizing the distance is far away, some may take electricity is very difficult, if the network video server with POE function, so can save the wiring and take the trouble of electricity, but also can save electricity.
single video server system integration application, is only a primary application of the real is the powerful system integration ability.The soul of
video server is software system integration, in situations where there is no standard, is more of a manufacturer's own system.
the level of system integration and acceptance capability of the scale of software and hardware structure way.Sometimes generally buy video server will send software, it can form a complete set of system application, can not adapt to large-scale application.So large-scale applications, consider good software 'way, under the corresponding distributed solution, etc.That is consider to choose a certain brand of hardware products at the same time, also want to consider the other's software can solve the actual demand of system, or any third party in the development of similar software, because large system software solving the manufacturer request is higher, and more can guarantee the follow-up service.So, when the choose and buy the video server, emphasize the hardware at the same time, also don't ignore software.
in unattended voice intercom function, the best application of the remote control, of course there is also need to choose a on the bandwidth control, audio and video synchronization processing power have a certain level of products is guaranteed.Voice intercom, can realize the exchange with the unimpeded.At present, many products on the market have voice intercom interface Settings, at the time of purchase products, please test the function in the network, if there is a delay test voice.
12, ADSL automatic dialing
regular ADSL broadband application must be driven by and ADSLModem connected computer dial-up Internet access.However, if the ADSL for remote monitoring access purposes only, so for a simple ADSL dial-up function in each monitoring front-end configuration of a computer, there is no doubt that caused the user equipment resources enormous waste.In these cases, whether have ADSL automatic dial-up function will directly affect the user's investment budget.
warranty, the warranty problem problem is one of the most concern for engineering contractor.Due to the engineering contractor directly in the face of the end user, unsatisfactory warranty service will receive effects the reputation of engineering contractor.Accordingly, can choose the famous brand, because small brands tend to price is not reasonable and the subsequent lack of technical support ability, and even some products by entering the market.Generally a one year free warranty for products of the manufacturer.