chapter 1 overview of network video surveillance technology
1.1 the development process of video surveillance technology随堂测验
1、the main application of network video surveillance technology is security prevention, which includes the main security elements ( ) a、goals to protect/person in charge of safet b、the physical prevention measures of the target encircling c、the extension mechanism of human visual perception (equipment) d、policies and regulations
2、the special function of "piercing eye" in the myth story is the remote video transmission function in the network video surveillance technology. ( )
3、the special features of the mythical story, "thousand-mile eye" and "wind-accompanying ear", correspond to the remote transmission of video and audio that can be realized in the widely used network video surveillance technology. ( )
1.2 the core technology of video surveillance technology随堂测验
1、the composition of analog video surveillance systems includes ( ) a、video signal acquisition part b、signal transmission part c、switching control part d、display and recording section
2、in the switching control part of the analog video monitoring system, its main function is to switch the video image and control the front-end equipment, mainly including ( ) a、matrix controller b、control keyboard c、control code generator d、monitor
3、the display and recording portion of the analog video surveillance system is mainly used to display and record the video signal transmitted by the front-end camera, and the display and recording equipment mainly includes ( ) a、monitor b、multi-screen divider c、multi-screen processor d、video cassette recorder
4、the digital video recorder is mainly composed of ( ) a、video capture card b、coding compression program c、storage device d、network interface and software system
5、the advantage of the digital video surveillance phase ( ) a、long recording time b、support multiple simultaneous recording c、image quality does not deteriorate over time d、complex system structure
6、in network video surveillance technology, the abbreviation cctv is a closed-circuit television monitoring system in the stage of analog video surveillance. ( )
7、the main function of the video signal acquisition part of the analog video surveillance system is to compress and encode the information. ( )
8、the signal transmission portion of the analog video surveillance system is responsible for the upstream transmission of the video signal and the downstream transmission of the control signal. ( )
9、the equipment that simulates the signal transmission part of the video surveillance system includes signal transceivers, signal amplifiers, coding compression chips, fiber optic cables, and so on. ( )
10、digital video surveillance began in the 1990s with a core device: digital video recorder (digital video recorder, dvr). ( )
11、the product form of the dvr includes pc and embedded, where pc software is built on the windows (or linux) operating system, so the structure is single and the performance is stable. ( )
1.3 the development direction of video surveillance technology随堂测验
1、the function of video encoding compression algorithm is to reduce the amount of video data under the premise of ensuring visual effect as far as possible, which is the premise of the digitalization and networking of video surveillance system. ( )
2、the core of video encoding compression is the algorithm, but the implementation of the algorithm is based on the computing processing chip. the algorithm is constantly improving to reduce the flow of code and improve the image quality, at the cost of improving the complexity of the algorithm, but does not require improve the processing power of the chip. ( )
1.4 abbreviations of terms随堂测验
1、based on the advent of high-definition network cameras, there are many advantages over traditional analog cameras and ordinary network cameras, including ( ) a、high definition, megapixel level sensor, and could get more video information; b、progressive scanning technology can make the picture clearer, natural and smooth without distortion; c、digital head control function, no mechanical parts, more stable and durable; d、it can replace many ordinary cameras for surveillance, saving cable, installation and maintenance costs.
2、the current status of network video monitoring system is that the coding equipment, platform software, storage and control equipment of different manufacturers cannot be interconnected, and the system needs secondary development and a large number of later integration. therefore, it is urgent to build an open video management platform to realize zero development interconnection. ( )
chapter 2 analog video surveillance system
2.1 composition of analog monitoring system随堂测验
1、typical analog video surveillance system structure includes ( ) a、front end: signal acquisition part b、middle: signal transmission part c、back end: matrix switching and control part d、display and video parts
2.2 video capture equipment随堂测验
1、the angle of view of the wide-angle lens is above ( ) a、20° b、30° c、40° d、50°
2、the main parameters of the camera ccd size refers to the diagonal size of the photosensitive surface of the ccd image sensor, the ccd area is different, the size of the photosensitive point is also different. the photosensitive point is responsible for photoelectric conversion. the larger the area, the weaker the sensitivity to light and the less rich the image hierarchy described. ( )
3、resolution refers to the image quality index used in the process of video recording, transmission and display, or the inherent screen structure of the display device to express the fineness of the image, that is, the scanning format or display device of the single image signal pixel specifications. ( )
4、0.25lx / f1.4 / 50ire / agc on means that the low illuminance of 0.25lx is measured with f1.4 luminous flux lens and video signal measurement voltage under 50ire (350mv) and agc is on. ( )
5、the camera has a video amplifier that amplifies the signal from the ccd to a "usable level". automatic gain control (agc) is to control this video amplifier to weaken the signal under low light and work under strong light, so that the camera can work in a larger illumination range. ( )
6、the focal length of the lens determines the size of the image formed by the subject on the ccd. the shorter the focal length, the smaller the shooting range, and the longer the focal length, the greater the angle of view of the lens. ( )
7、the selected lens should be consistent with the size of the target surface of the camera, and the ccd of the large-size target surface can use a small-size lens, and vice versa. ( )
8、the c-type lens is equipped with a c-type camera, the cs-type lens is equipped with a cs-type camera, and the cs-type lens with a 5mm adapter is equipped with a c-type camera. ( )
2.3 signal transmission equipment随堂测验
1、the function of the video distributor is one channel of video input and multiple channels of video output, with the functions of impedance matching and signal amplification. ( )
2、the power supply of the network video surveillance system generally requires that the power cord and signal cord be as short as possible. ( )
2.4 matrix control equipment随堂测验
1、the matrix switcher can realize the selection and output of the image of any camera on any designated monitor. through the keyboard, you can control the front-end camera, lens and auxiliary equipment. ( )
2.5 display and video equipment随堂测验
1、the multi-screen splitter still plays back the split screen after playback, and the single-screen playback is as clear as the original image. ( )
chapter 3 video coding and compression technology
3.1 basics of multimedia technology随堂测验
1、in a multimedia system, it must involve using different color models to represent the colors of an image. for example, the yuv color model is used for computer display, the rgb color model is used in the color tv digitization system, the cmyk color model is used for color printing, and so on. ( )
2、the rgb color model, that is, the three primary colors, 8-bit coding of the rgb three primary colors each constitutes about 167,000 colors, which is what we often say is true color. ( )
3、the yuv color space is composed of a luminance signal y and two color difference signals and chrominance signals u and v. the separation of y, u and v is to realize the color signal received by black and white tv. ( )
4、the hsl color model refers to the hue, saturation, and brightness color models, where h represents the wavelength of the color, called hue, which refers to the purity of the color, or the depth of the color. ( )
3.1 basics of multimedia technology随堂测验
1、the display resolution of an image is a measure of the density of pixels that make up an image. ( )
2、pixel depth refers to the number of bits used by each pixel and determines the number of colors that each pixel may have. ( )
3.2 data compression methods随堂测验
1、the premise of data compression is that there is more or less redundant information in the data, and for multimedia information such as video and audio, humans can use their own perceived redundancy (distortion) characteristics to achieve a higher compression ratio. ( )
2、human vision is sensitive to color changes and weak to brightness resolution, so video coding algorithms need to make full use of the "weakness" of the human eye for "deceptive" design. ( )
3.2 data compression methods随堂测验
1、the principle of coding is to convert the codes that are used many times into codes with a long length, while those with few usages can use shorter codes, and keep the codes only solvable. ( )
3.2 data compression methods随堂测验
1、the principle of run-length coding is to replace a continuous string with the same value with its string length and a representative value. this continuous string is called a run-length. for example, aaaaaaaaabbbbbbbbbbccddddeeee, after encoding is 9a10b2c4d4e. ( )
3.2 data compression methods随堂测验
1、the idea of lzw encoding is to build a string table of the encountered strings, each string in the table corresponds to an index, and the index of the string in the string table is used to replace the original string when encoding. ( )
3.2 data compression methods随堂测验
1、the essence of discrete cosine transform is to convert a set of frequency data into light intensity data. ( )
2、the dc coefficient (dc) after the discrete cosine transform is also called the high-frequency component and represents some details of the image, not the most important information. ( )
3.2 data compression methods随堂测验
1、in jpeg encoding, the dc coefficient encoding reflects the main information (average brightness) of the 8*8 data block, and generally has a large correlation with the adjacent block, so the dc coefficient is differentially encoded, and then the actual value and prediction of the current block are calculated. the difference of the values is finally huffman encoded. ( )
2、in jpeg encoding, before the dct change of the image, the color mode conversion of the image is required. jpeg is required to be performed in the rgb color mode. ( )
3.3 dynamic video compression随堂测验
1、dynamic video compression, that is, there is "opportunity" for redundant data, lies in ( ) a、spatial redundancy b、time redundancy c、thinking redundancy d、visual redundancy
2、spatial redundancy in dynamic video compression refers to the large correlation between two adjacent images in the image sequence. ( )
3.3 dynamic video compression随堂测验
1、generally, the video coding algorithm divides the input cif video into a series of "block" based hierarchies, including: ( ) a、picture b、gob c、mb d、block
2、the demand of image universal format is to make all kinds of current tv systems (pal, ntsc, secam images) can be easily converted into tv phone images. ( )
3、cif format is based on ycrcb color mode. there are 352 horizontal pixels and 288 vertical pixels in component y, cr and cb. ( )
4、block is the basic unit of motion compensation. ( )
5、block is the basic unit of dct. ( )
3.3 dynamic video compression随堂测验
1、the standard resolution of standard digital pal tv is: ( ) a、720×576 b、720×625 c、1024×768 d、1920×1080
2、the advantage of interlaced scanning is that the image drop is not much and the channel efficiency is doubled. ( )
3、frame rate is the number of frames transmitted and displayed in one second. it can also be understood as the data flow size of video data in unit time. ( )
3.3 dynamic video compression随堂测验
1、the output of the time domain model is the residual image obtained by subtracting the current frame from the predicted frame and the motion model parameters (such as motion vector): ( ) a、residual image b、motion model parameters c、motion vector d、dct quantization coefficient
2、the main function of dynamic video compression time domain model is to eliminate the redundancy between consecutive video frames. ( )
3、difference (residual image) refers to the difference between the corresponding pixels of the two frames. ( )
3.4 mainstream video coding technology随堂测验
1、the mpeg standard is a series of standards for moving image compression. so far, the standards that have been developed and are being developed are: ( ) a、mjpeg compression b、mpeg-1-digital tv standard, officially released in 1992 c、mpeg-2-digital tv standard, became a draft international standard in 1994 d、mpeg-4-multimedia application standard, released in 1999
2、evaluation criteria of video image coding and compression technology ( ) a、bit rate b、reconstructed image quality c、encoding / decoding delay d、the capability of error repair
3.4 mainstream video coding technology随堂测验
1、mjpeg encoding compression technology is a dynamic image compression method based on the development of static image compression technology, which can compress continuous video streams to produce an image sequence. its advantages are: ( ) a、relatively simple to implement b、encoding delay is small c、the picture can be spliced arbitrarily (the picture does not matter directly) d、can flexibly adjust the compression frame rate and resolution
3.4 mainstream video coding technology随堂测验
1、in order to obtain high compression ratio and high-quality images that can be randomly stored under the condition of efficient encoding and compression, mpeg defines three frame types, namely: ( ) a、i-frame b、p-frame c、b-frame d、t-frame
2、the i-frame is implemented using a jpeg-like coding method. it does not use any other frame as a reference, but only performs spatial redundancy compression within the frame. ( )
3、since the i-frame image needs to refer to other image frames, the information of this frame is not used for encoding, so the amount of data is small. ( )
4、the characteristic of the p-frame is that it is the forward prediction result of the previous i-frame or p-frame, and it is also the reference reference image for the next p-frame. ( )
5、p-frame can provide the highest compression ratio. it can use the past image frame (i-frame or p-frame) or the subsequent image (i-frame or p-frame) for motion-compensated bidirectional predictive coding. ( )
6、since the video encoding process requires unidirectional or bidirectional reference prediction, the order of image compression, transmission, and display is not consistent. ( )
3.4 mainstream video coding technology随堂测验
1、the incorrect description about mpeg-1 is ( ) a、the standard was published in 1992 b、it is mainly used for dvd, mp3 music c、mpeg-1 uses block motion compensation d、mpeg-1 uses discrete cosine transform
3.4 mainstream video coding technology随堂测验
1、the incorrect description about mpeg-2 is ( ) a、it was released in 1994 b、it is usually used to provide video and audio encoding for broadcast signals c、mpeg-2 is the core coding technology of dvd products d、forward compatible
3.4 mainstream video coding technology随堂测验
1、the incorrect description about mpeg-4 is ( ) a、it was released in 1998 b、the core of the algorithm is to support "content-based" encoding and decoding functions c、it specifies natural audio and video objects d、it specifies including text, 2d and 3d graphics and synthesized speech
2、because mpeg-4 encodes each object independently, it can achieve a high compression ratio, and at the same time, it also provides the possibility to operate the content on the receiving end as needed, adapting to the needs of "human-computer interaction" in multimedia applications. ( )
3、the advantage of mpeg-4 technology is that it treats images equally. ( )
4、the traditional video encoding method is to process the entire video signal as a whole content, which can not be divided anymore, mpeg-4 encoding can achieve the complete extraction of a video information from the video signal, to meet human recognition habits of visual information. ( )
chapter 4 hard disk video recorder (dvr) technology
4.1 dvr product introduction随堂测验
1、the core functions of dvr are ( ) a、digitalization of analog audio and video b、code compression c、storage d、network transmission
2、as can be seen from the composition of dvr, apart from the computer system equipment as the basic load, such as cpu and memory, there are two main core chips necessary for dvr: ( ) a、a / d chip b、network card c、back-end processing chip d、hard disk
3、dvr configuration and interface need to consider the following elements: ( ) a、support resolution b、number and capacity of hard disks c、number of video input and output d、alarm interface, etc.
4、the difference between hard compression and soft compression in dvr is "who completed the encoding compression?" if it is done by the hardware chip on the board, it is called hard compression. if it is handed over to the cpu to complete, it is called soft compression. ( )
5、the compression algorithm is provided by the asic chip manufacturer and is solidified on the asic chip at the factory. it has advantages in cost and performance, but lacks flexibility and scalability. ( )
6、dsp is a general-purpose media processor, with software programmable features that can fully support a variety of encoding compression algorithms, but product expansion and upgrade is more difficult. ( )
7、dvr recording file management has two management methods: video streaming (v type) and file packaging (f type). the efficiency of v storage playback is high, but the video cannot be directly recognized by other computer equipment, and the software needs to be extracted and converted. f-type storage and playback efficiency is poor, but the standard format is used, which is basically universal. ( )
8、dvr's discussion on the number of channels believes that the more channels supported, the better, and it is a manifestation of the manufacturer's strength. ( )
4.2 dvr hardware and software composition随堂测验
1、the description of the a/d conversion device in dvr is correct ( ) a、convert the analog video signal into a standard digital signal b、provide encoding or compression chip dsp or asic for encoding c、video and audio require different a / d conversion equipment d、the video and audio signals must be synchronized
2、the software composition of the embedded dvr includes ( ) a、application software program b、operating system kernel part c、device driver d、encoding compressor
3、advantages of pc-style dvr ( ) a、complete interface b、low development cost c、short development cycle d、powerful network
4、embedded dvr function advantage ( ) a、small software code b、highly automated c、fast response d、suitable for applications requiring real-time and multi-task
5、compared with pc-type dvr, embedded dvr has an advantage in that it has a friendly interface. ( )
6、pc-type dvr is equivalent to pc plus video capture card. ( )
7、the embedded dvr is stable. the operating system and software are solidified in flash or rom, there is basically no possibility of system files being destroyed, and the reliability is high. ( )
4.3 dvr software functions随堂测验
1、dvr video management includes ( ) a、manual start-stop video recording b、dynamic trigger recording c、alarm event recording d、schedule recording
2、the alarm management mode of dvr (non-manual alarm) includes ( ) a、external contact alarm mode b、external api alarm mode c、vmd alarm mode d、timing alarm mode
3、entity rights in dvr user rights include ( ) a、manage camera video channels b、audio channel c、video recorder d、storage device
4.4 dvr application architecture随堂测验
1、dvr video management includes ( ) a、manual start-stop video recording b、dynamic trigger recording c、alarm event recording d、schedule recording
2、the alarm management mode of dvr (non-manual alarm) includes ( ) a、external contact alarm mode b、external api alarm mode c、vmd alarm mode d、timing alarm mode
3、entity rights in dvr user rights include ( ) a、manage camera video channels b、audio channel c、video recorder d、storage device
4、dvr's multi-stream technology is implemented in the following ways ( ) a、double coding chip b、stream dilution c、high performance single chip d、qos (quality of service)
5、in dvr application of digital-analog hybrid architecture, dvr is generally only used as an independent video recording device. ( )
6、in dvr application multi-level networking mode, the system usually has multiple dvrs and a central data server. due to the large number of dvr, it is necessary to set up a global central database in order to complete the unified management of equipment and flexible distribution of rights. ( )
7、in dvr multilevel networking mode, relevant operations always pass through the central server. ( )
4.5 highlights of dvr随堂测验
1、what are the highlights of dvr selection ( ) a、video analysis technology b、hybrid dvr technology c、intelligent retrieval and playback d、video encryption technology
4.6 dvr product selection随堂测验
1、which is the key issue to consider when selecting dvr ( ) a、system stability b、image resolution c、coding compression algorithm d、image retrieval function
2、the standards for measuring the advantages and disadvantages of coding and compression algorithms are ( ) a、definition of image b、real time c、mosaic effect d、smoothness, etc.
3、at present, dvr products are mostly distributed and cross-regional, so the stability of the system will be the top priority. ( )
4、the image definition of dvr products is the most concerned problem for users, without considering cost factors such as equipment cost, bandwidth, storage, etc. ( )
5、when considering dvr network functions, it depends not only on whether the product provides ethernet network interface, but also on whether it provides supporting centralized monitoring and management system software and related functional support. ( )
4.7 common faults of dvr随堂测验
1、pc type and embedded dvr, common fault is board looseness. ( )
4.8 dvr practical application operation随堂测验
1、which of the following video traffic needs to be considered in dvr bandwidth design ( ) a、browse video stream in real time b、real-time storage of video streams c、archive backup video stream d、display device video stream
chapter 5 digital video server (dvs) technology
5.1 dvs product introduction随堂测验
1、as the core hardware product of network video monitoring system, which of the following key indicators does dvs have ( ) a、image quality b、delay c、network adaptability d、qos
2、video encoder is also called video server, or dvs (digital video server) for short. it is mainly used to encode and compress analog video signals and provide network transmission function. the difference with dvr products is that dvs focuses on the "video recording" function. ( )
3、dvs can be seen as a transition product of video surveillance system from analog era to network era. using dvs, you can upgrade to network system without abandoning the existing analog equipment. ( )
4、compared with dvr, dvs is not suitable for application in projects with scattered points. ( )
5、dvs can be seen as a function split of dvr in essence, that is, the coding and compression devices are completely independent from dvr and distributed and deployed at the front end. ( )
6、dvs itself is a video capture and encoding device, which has the same "individual combat" capability as dvr. ( )
7、the weakness of dvs lies in its strong dependence on network. ( )
5.2 dvs software hardware composition随堂测验
1、from a functional perspective, the software architecture of dvs client can be divided into 3 modules ( ) a、equipment control module b、network receiving and feedback module c、display module d、memory module
2、the network interface part of dvs is responsible for packaging and uploading the encoded and compressed data stream to the network. ( )
3、when dvs is applied to network transmission, the common system adopts two communication protocols, tcp/ip protocol to transmit video data and udp/ip protocol to transmit communication control data. ( )
5.3 dvs system application architecture随堂测验
1、the application mode of combination of matrix and dvs is mainly applied to the upgrading of the original analog video monitoring system. ( )
2、the architecture of "dvs nvr" is a network video monitoring system composed of part of digital and part of analog, which is generally adopted for newly-built projects. ( )
3、under the "dvs nvr" architecture, all devices (dvs, nvr, storage and decoding display devices) are not limited by physical conditions. the only consideration is "user deployment location and application requirements" and resource allocation is based on the network bandwidth designed in advance. ( )
5.4 dvs highlight function随堂测验
1、anr technology, namely automatic network replantation, also known as "breakpoint resume technology", is a technology that combines local storage and network storage, and is mainly used to solve the problem of video loss when the network fails. ( )
2、in case of dvs failure, the redundant encoder will start and perform coding compression, and the video stream will be recorded in the "account" of the redundant encoder. ( )
3、poe(power on ethernet) power supply technology is a technology that transmits data and power required by equipment simultaneously through a network cable.users do not need to separately lay power cables, which can effectively simplify the deployment of front-end cables and save costs. ( )
5.5 dvs product selection随堂测验
1、the video analysis based on the front-end encoder is completed at the front end, which can not only reduce the pressure of network real-time transmission, but also reduce the pressure of back-end server's operation processing, and make the video content analysis more distributed and real-time. ( )
2、the back-end service (or nvr server) mode is adopted to analyze the internal users of the video. since the video signal has no distortion compression, more false negatives and false positives are avoided. ( )
chapter 6 network video recorder (nvr) technology
6.1 nvr product introduction随堂测验
1、the pc nvr has the following advantages: ( ) a、universal hardware interface b、open c、standardization d、good compatibility
2、nvr, the full name of network video recorder, is the storage and forwarding part of the network video surveillance system. nvr works with the video encoder (dvs) or network camera to complete the video recording, storage and forwarding functions. ( )
3、nvr is a network-based all-ip video surveillance solution, but it cannot be deployed anywhere on the network due to physical location constraints. ( )
4、nvr can be understood as software in essence, but the realization of its complete function is inseparable from the carrier of computer platform. ( )
5、similar to dvr, nvr can also work independently and form its own system. ( )
6、nvr software product (software only) means that the manufacturer provides the nvr software plus license mode, but it needs to be installed on specific hardware. ( )
6.2 nvr technical indicators随堂测验
1、nvr is a centralized storage device. the more channels a single device can support, the lower the cost. therefore, the system channel capacity is a very important indicator to measure nvr. ( )
2、nvr is a centralized storage device. the more channels a single device can support, the higher the cost. therefore, the system channel capacity is a very important indicator to measure nvr. ( )
3、the nvr needs to manage the allocated disk space and write to the video stream. the disk capacity supported by each nvr is also limited. the storage space supported by a single nvr will become a bottleneck. ( )
6.3 highlights of nvr随堂测验
1、the characteristics of middleware are correctly stated ( ) a、runs on a variety of hardware and os platforms b、supports standard protocols and interfaces c、supports distributed computing d、provide transparent application or service interaction
2、middleware is to solve this distributed heterogeneous problem. middleware is a large category of basic software and belongs to the category of reusable software. ( )
3、middleware is under the "infrastructure" of hardware, operating system, network and database, and above the application software. ( )
6.4 nvr product selection points随堂测验
1、the storage system of nvr is developing towards mass storage, centralized storage and reliable storage. requirements: ( ) a、the storage time of nvr recording needs to be longer and longer b、multi-channel nvr system concurrent storage or playback requires higher and higher disk i/o indicators c、requires that the storage system cannot be shut down d、able to perform hard disk replacement online
2、the advantage of software only-style nvr is that users can have more choices of hardware platforms. the disadvantage is that performance may not be guaranteed, and after-sales service may need to coordinate multiple solutions. ( )
3、the function of nvr is video storage, but the number of video recording channels supported by a single nvr will not directly affect the construction cost of the system. ( )
6.5 nvr application case analysis随堂测验
1、when deploying an nvr project, you first need to understand the specific characteristics of the project, including: ( ) a、industry characteristics and special needs of users b、number of cameras, distribution of points c、storage system architecture d、network construction, etc.
chapter 7 network camera (ipc) technology
7.1 introduction to ipc products随堂测验
1、ipc, full name ip camera, namely network camera, is a real ip monitoring equipment. it works together with network video recorder or media server to form a complete network video monitoring system, and together complete video coding, transmission, storage and forwarding functions. ( ) a、industry characteristics and special needs of users b、the number of cameras, point position distribution c、the architecture of the storage system d、network construction and so on
2、ipc, ip camera, is a real ip monitoring device. the most important feature is that the camera supports the network protocol. ( )
3、ipc can be regarded as "analog camera video encoder" in terms of function, but the image quality is smaller than "analog camera video encoder". ( )
4、megapixel cameras are usually equipped with megapixel image sensors, whose high pixel level brings higher requirements for network bandwidth and storage. ( )
5、ipc is more than analog camera signal conversion (4:1), so the image quality is reduced. ( )
6、the highest resolution of the analog camera is at the level of 400,000 pixels, so it can meet the application requirements for some large-scale scene monitoring or situations where detailed features need to be displayed. ( )
7、ipc technology itself makes it easy to integrate audio capabilities. ( )
7.2 the composition and working principle of ipc随堂测验
1、ipc's hardware configuration typically does not include which of the following options ( ) a、shot b、image/sound sensor c、network and control interface d、store the hard disk
2、the software components of ipc generally include ( ) a、operating system b、internet applications c、encryption algorithm d、bottom-driven
3、ipc software uses a layered architecture, including ( ) a、device driver layer b、operating system layer c、media layer (multimedia library and network protocol stack) d、application layer
4、from the external situation, ipc is integrated into video acquisition, image processing, video and audio coding and compression, network transmission, control, alarm and other functional modules on a circuit board to achieve video coding and uploading. ( )
5、in ipc's independent chip cpu architecture, the coding and compression work is done on the same chip as the system master. ( )
6、ccd sensor is poor in terms of sensitivity and image quality. the reason is that each pixel of ccd needs an a/d, which reduces the photosensitive area of each pixel. in addition, the use of pixel equivalent a/d converter will also cause high noise interference. ( )
7、cmos based image sensor is generally built with a/d module, which can output digital signals directly, so no analog/digital converter is needed. the image sensor module based on ccd mode needs an independent a/d conversion device. ( )
8、ipc has a hardware coding compression mode, that is, the coding compression algorithm is solidified on the chip. ( )
7.3 ipc core technology随堂测验
1、when it comes to the core technology of ipc, in terms of hardware, ipc is mainly composed of ( ) a、optical element b、photosensitive imaging device c、ic chip d、circuit board
2、when it comes to the core technology of ipc, in terms of software, it mainly includes ( ) a、video coding and compression algorithm b、video analysis algorithm c、a computer software program d、encryption algorithm
3、different companies use different imaging devices, different chips, and different compression algorithms, resulting in ipc devices with very different performance. ( )
7.4 highlights of ipc随堂测验
1、there are generally three ways to protect the data security of ipc: ( ) a、ip filtering mode b、username and password method c、data encryption d、information hiding
2、ipc is similar to dvs in that one of ipc's weaknesses is that it is too dependent on the network, so it needs ipc to have temporary local video data storage capacity. ( )
3、alarm frame rate change technology refers to that ipc adopts low resolution and frame rate to record video in normal state, but once an event or alarm occurs, the system automatically switches to high resolution and frame rate to record video, which can save a lot of storage resources and ensure high quality recording of important videos. ( )
4、vmd (video motion detection), a video analysis function, is mainly used to monitor a video scene or an area to determine whether there is a change and send an alarm. vmd function is suitable for outdoor environment application, indoor environment false alarm is higher. ( )
7.5 ipc selection points随堂测验
1、video image quality is the soul of the camera and the most important indicator of the video surveillance system. without good image quality, any other rich functions are meaningless. in terms of optical devices, the image quality is closely related to the lens and sensor. ( )
2、the image quality of ipc is only composed of optical devices, and there is no difference in the image quality obtained by different coding and compression algorithms. ( )
3、network adaptability of ipc mainly refers to the network latency of ipc and whether ipc can still perform well in the case of poor network environment (such as packet loss and jitter). ( )
7.6 ipc application design随堂测验
1、ipc application design, first, needs to be specific to the requirements of the project, including ( ) a、the number of points b、point position distribution c、the architecture of the storage system d、network construction
2、monitoring requirements and scope factors together determine the type of ipc, fixed or ptz, installation location, megapixels, and so on. ( )
3、ipc design needs to consider the installation environment, the installation environment is to determine the sensitivity of the camera, and the choice of protective cover is irrelevant. ( )