CCTV installation Melbourne reducing the amount of data transferred and stored in a network video system. There are advantages and disadvantages to each, so it is best to consider the goals of the overall surveillance system when deciding which of the two standards is most appropriate. Due to its simplicity, Motion JPEG is often a good choice. There is limited delay between image capturing, encoding, transfer, decoding, and finally display. In other words, Motion JPEG has very little latency, making it most suitable for real-time viewing, image processing, motion detection or object tracking. Motion JPEG also guarantees image quality regardless of movement or image complexity. It offers the flexibility to select either high image quality (low compression) or lower image quality (high compression), with the benefit of smaller file sizes and decreased bandwidth usage. The frame rate can easily be adjusted to limit bandwidth usage, without loss of image quality. However, Motion JPEG files are still typically larger than those compressed with the MPEG-4 standard. MPEG-4 requires less bandwidth and storage to transfer data resulting in cost savings. At lower frame rates (below 5 fps) the bandwidth savings created by using MPEG-4 are limited. Employing Motion JPEG network cameras with video motion detection built in, is an interesting alternative, if a higher frame rate is only required a portion of the time when motion is in the image. If the bandwidth is limited, or if video is to be recorded continuously at a high frame rate, MPEG-4 may be the preferred option. Because of the more complex compression in a MPEG-4 system, there is more latency before video is available at the viewing station. The viewing station needs to be more powerful (and hence expensive) to decode MPEG4, as opposed to the decoding of Motion JPEG streams. One of the best ways to maximize the benefits of both standards is to look for network video products that can deliver simultaneous MPEG-4 and Motion JPEG streams. This gives users the flexibility to both maximize image quality for recording and reduce bandwidth needs for live viewing. One other item to keep in mind is that both MPEG-2 and MPEG-4 are subject to licensing fees, which can add additional costs to the maintenance of a network video system. It is important to ask your vendor if the license fees are paid. If not, you will incur additional costs later on.
Other Considerations another important consideration is the use of proprietary compression. Some vendors don’t adhere to a standard 100 percent or use their own techniques. If proprietary compression is used, users will no longer be able to access or view their files should that particular vendor stop supporting that technology. Proprietary compression also comes into consideration if the surveillance video will potentially be used in court. If so, using industry standard compression ensures that video evidence will be admissible. Some courts believe that evidentiary video should be based on individual frames, not related to each other or manipulated. This would eliminate MPEG because of the way the information is processed. The British court system, which has been leading digital video admissibility, requires an audit trail that describes how the images were obtained, where they were stored, etc., to make sure the information is not tampered with in any way. As digital video becomes more widely adopted, the issue of admissibility in court will be one to watch.
Compression is one of the most important factors to building a successful network video system. It influences image and video quality, latency, cost of the network, storage, and can even determine whether video is court admissible. Because of these considerations, it is important to choose your compression standard carefully … otherwise, the video may be rendered obsolete for your purposes.
Does one compression standard fit all? When considering this question and when designing a network video application, the following issues should be addressed:
• What frame rate is required?
• Is the same frame rate needed at all times?
• Is recording/monitoring needed at all times, or only uponmotion/event?
• For how long must the video be stored?
• What resolution is required?
• What image quality is required?
• What level of latency (total time for encoding anddecoding) is acceptable?
• How robus/secure must the system be?
• What is the available network bandwidth?
• What is the budget for the system?
Corner Thin/Wide Box Mounting The corner thin/wide box is designed to be installed with a gooseneck tube.
• Dome Camera
• Gooseneck Tube and other equipped items (optionalaccessory)
• Corner Thin/Wide Box (optional accessory)
• Waterproof Rubber (standard accessory for the outdoordome)
• Screws and Screw Anchors for fixing the Corner Thin/Wide Box (not supplied)
• Tool for drilling
• Tool for screwing
Follow the steps to mount the dome with the corner box and gooseneck tube.
- Make a cable entry hole on the wall to recess the cables. Otherwise, cables can be threaded through the cable entry hole on the tube.
- Fix the Corner Thin/Wide Box on corner wall with proper screws and screw anchors (not supplied).
- Attach the gooseneck tube to the fixed corner box with the supplied screws and washers.
- Attach the waterproof rubber to the gooseneck tube.
- Thread the cables through the gooseneck tube and the top holder.
- Fix the top holder to the gooseneck tube with the supplied screws and washers. Then adjust the waterproof rubber to the junction of straight tube and top holder.
- Connect the cables to the dome camera. Then attach the dome to the top holder and fix them with the supplied screw.