Hikvision's Turbo HD: Bringing HD quality to an analog system
Editor / Provider: Sponsored by Hikvision | Updated: 9/22/2014 | Article type: Tech Corner
Regardless of whether or not video surveillance is headed toward IP, analog will always have a place in the market. The ease of connection, immediate transmission rate, simple maintenance, and safe and stable application will all keep analog a mainstay in video surveillance. To fit some systems integrators and end users' needs for analog systems, Hikvision launched its first HD analog systems, Turbo HD, ranging from cameras to DVRs.
How does Turbo HD Analog Solution work?
The Turbo HD analog system integrates digital, codecs, modem, and analog transmission technologies, which breaks the limit of 625TVL (not 960H) simulation technology and allows for HD in analog transmission, making it easy for old systems to upgrade to HD.
At the core of Hikvision's Turbo HD analog system is a modem chip that processes HD signals. After the HD signals are captured by the megapixel high-resolution CMOS sensor, the optical image is processed by the image chip and forms uncompressed digital signals, which saves the original information. This imaging principle is basically the same as that of a HD digital camera, but the difference is Turbo HD analog solution adopts analog transmission over coaxial cable, namely, digital signals that are modulated into analog signals by a modulation chip. After HD video signals are transmitted to a back-end DVR, the modulation chip demodulates and uses a codec to compresses them into HD net video signals, which are then stored. The DVR modulation chip can modulate four Turbo HD signals in order to improve efficiency of demodulation.
• HD visual effects: Currently, Turbo HD analog solution is available in two resolutions: 2 megapixels at 1,080P and 1.3 megapixels at 720P. This allows for 900TVL to 1,100TVL of HD quality, which should be able to satisfy most HD surveillance needs.
• Long-distance transmission: It transmits 1,080P over 300 meters via a 75-5 ohm coaxial cable and 720P up to 500 meters.
• Open platform: Hikvision's Turbo HD analog system is compatible with HDTVI products of same type from third party companies. It can also receive different signals from 1,080P network cameras, 960H cameras, and SD analog cameras.
• Reverse control over coaxial cable: There is no need for customize configured keyboards for the OSD function menu of front-end cameras and dome camera cradle controls—everything can be done through the DVR via coaxial cable, providing the same flexibility as network equipment.
• Multi-functions: Software allows IP cameras to have many functions; however, many of these functions are difficult to realize on an analog camera. With the Turbo HD analog system, there are more functions such as transmission through fog, WDR, backlight compensation, and the intelligent analysis of VQD.
Like other product lines, the Turbo HD analog system is selfcontained. To meet the needs of different customers, it provides a variety of camera series including dome cameras, half-dome cameras, fixed cameras, bullet cameras, integrated cameras, non-spherical camera, etc., all designed with infrared supplementary lighting and are IP66-rated for indoor and outdoor use.
Hikvision also provides several types of Turbo HD DVRs: mainly 4-, 8-, and 16-channel products. From the outside, the Turbo HD DVR looks the same as a traditional DVR. However, once the back cover is opened and you look at the PCB, you will find there are four HDTVI demodulation chips in addition to the video processing chip. In addition, the BNC video input interfaces for the Turbo HD DVR are not separated for SD and HD — the DVR recognizes the signals and resolution after analog video is input though these interfaces. As to DVR, the Turbo HD analog and IP inputs are two individual signals that do not restrict each other. Take DS-8116HQHI-SH as an example. This DVR supports 16 channels of analog video and two channels of network video input and can realize maximum codec storage of 18 channels of 1,080P HD signals.
Eight channels with 1,080P and 720P Turbo HD cameras, as well as one channel with a 2-megapixel HD IP cameras, one channel with a D1 HD analog video, and one channel with a 960H camera; 10 channel signals in total were used for the test. They are tested and stored in a DS-8116HQHI-SH VCR (available with eight Western Digital 4TB hard drives). Turbo HD cameras need one-to-one corresponding modem chips to receive video signals. For this test, the camera was connected directly to the DVR. The video was then uploaded to Skyworth's display's DVR HDMI interface and co-browsed through C/S client from an Internet-connected computer.
Image quality test: 1,080P HD Picture Quality
With the DS-2CE16D5T-AVFIT3 as the video source, the camera was aligned at the sharpness testing card and focus at minimum zoom. The observed local output video showed horizontal 1,050TVL and vertical 1,100TVL. The camera's wide-angle lens caused poor edge sharpness, but still provides up to 800TVL. The results were almost the same with 1,080P IP HD, and even better than some 1,000TVL IP HD.
With the 24-color reduction test card, the reduction was accurate with no partial color. Compared with IP HD images, the color was more transparent, closer to the color performance of HD-SDI digital signals with codec. At the same time, in the gray scale test, the gray-scale performance at the seventeenth and eighteenth levels were not inferior to IP camera either.
In the scenery image quality test, the pictures were penetrating, smooth, and layered—so much so that you would not believe they came from an analog system. The superior color reduction is closer to that of SDI digital pictures without compression loss.
In addition to the transmission test at short range, we also tested 1,080P at 300 meters over a 75-5 ohm coaxial cable. In the sharpness test, after a 300-meter long transmission, the image quality of 1,080P was not reduced: horizontal 1,050TVL; vertical 1,100TVL; and edge 800TVL were all easily distinguishable with accurate color reduction. Meanwhile, in long-distance transmissions, when placing a telephone next to the coaxial cable and camera to cause signal interference, no abnormalities appeared in the picture.
Network Design With Flexible Controls
Although the Turbo HD analog system uses analog signals to transmit signals, it incorporates Hikvision's network advantages into its new generation of Turbo HD products, such as WDR support, defog, backlight compensation, etc. During the test, a fog simulation test was conducted: when the defog function was off the picture was hazy; however, after turning on the function, the outline of the picture was clear, and the effect on the video in terms of penetration, color, and sharpness was close to that in a no-fog situation. Similarly, in the backlight compensation test, when the backlight compensation was turned on under hard light the ambient light was suppressed as well, making the doll easily identifiable.
In the test, the codec parameter was set for 1,080p video to 1,080P/4 Mbps (under real-time 25fps). HD video was previewed at C/S client-side after codec by DVR (the code rate was steadily controlled between 4.4 to 4.5 Mbps). When delayed, focusing the camera on the electronic stopwatch the delayed time of 1,080P Turbo HD from imaging to display according to DVR local display and photo capture was calculated to be about 170 to 220 milliseconds, proving the fast transmission rate of the picture.
Replay: Fast Operation and Smooth Replay
The DVR also has intelligent analytic functions, such as a tripwire test. It can monitor video channel quality in real time, including diagnostic functions for blurry images, abnormal brightness, and crash screens, as well as immediately preserve the monitor screen.
DVR DS-8116HQHI-SH supports a maximum of 18 channels of video recording and a maximum of 16 channels of 1,080P synchronous replay. After four to five hours of constant recording, video can quickly be retrieved via time and/or channel through the replay menu. For this test we replayed 10 channels: observed was no frame loss in the picture and smooth replay. Note that the image quality, color, and sharpness could fully meet the requirements of HD forensics. In the test, the codec parameter was set for 1,080p video to 1,080P/4 Mbps (under real-time 25fps). HD video was previewed at C/S client-side after codec by DVR (the code rate was steadily controlled between 4.4 to 4.5 Mbps). When delayed, focusing the camera on the electronic stopwatch the delayed time of 1,080P Turbo HD from imaging to display according to DVR local display and photo capture was calculated to be about 170 to 220 milliseconds, proving the fast transmission rate of the picture.
Single channel replay, real-time image quality
During single-channel video replay, we called up the data rate testing software. After a long period of observation, we found that the camera used real-time replay buffer technology of 1,080P real-time replay at about .4 to 4.5 Mbps for singlechannel replay, conforming to codec limits and consistent with those in real-time preview. To reduce storage space and bandwidth pressure in remote preview or replay, 1,080P can be encoded and decoded at a rate of 2 to 3 Mbps or 720P at 1 to 2 Mbps, all while ensuring image quality with DVR low-coding technology. There is no obvious decay of image quality between low-code stream and standard-code stream transmission.