High-definition applications need to be improved. Multi-faceted selection analysis of hybrid DVR

Hybrid DVR can capture the video stream of encoder or IP camera through the network and store it on the hard disk space of DVR. Hybrid DVR is to adapt to the transition from DVR to NVR. Since both exist in the short term, especially for the original system deployed with DVR, when IP cameras are to be added, hybrid DVR is a good choice without changing the system architecture and equipment. When the product enters the market, what performance should we pay attention to when purchasing? In addition, in the process of product promotion, what kind of improvement and upgrade will the hybrid DVR product make?

A wide range of options:

The choice of hybrid DVR is multifaceted, including the security and reliability of the overall application. Regarding the analog encoding part, since the system is already very mature, the common performance options are as follows:

High-definition application capabilities

In consumer video applications, the demand for video clarity has always been an eternal topic. In security video surveillance, the demand for "high definition" is also increasingly mentioned. Full compatibility with high definition also puts higher requirements on video surveillance products. That is, not only does the network video acquisition require high definition, but the storage, preview display, and playback also need to be high definition.

The current mainstream hybrid DVRs often have HDMI high-definition output interfaces to enable high-definition display capabilities. At this time, it is also necessary to consider the video processing capabilities of the hybrid DVR, that is, how many channels of high-definition video decoding and display are supported at the same time, and how many channels of high-definition video synchronous playback are supported, which are also key parameters for measuring the performance of the hybrid DVR.

At the same time, in actual applications, especially phased projects or renovation projects, it is often necessary to connect to network cameras of multiple brands. Therefore, the compatibility of hybrid DVR with multi-brand network cameras is also a factor that must be considered in equipment selection.

At the same time, since the access to network cameras is more complicated than that to analog cameras, the ease of access to network cameras, whether it can support automatic search and addition of network cameras, simple configuration, etc., are also issues that need to be considered in actual applications.

Network front-end management capabilities

On the one hand, with the development of security products such as high-definition network cameras, network cameras, hybrid DVRs, and NVRs have achieved great development. On the other hand, we also realize that the access and management of network cameras lack unified industry standards. This phenomenon is more obvious in NVR products. Due to the differences in market positioning and technical accumulation of manufacturers, NVR products have diverse forms and obvious application differentiation. However, most customers still have relatively limited knowledge and lack of experience in network video surveillance systems. Such product differences not only fail to provide users with diverse choices, but also bring confusion in product functions and forms and confusion in user choices. Hybrid DVRs are also more or less affected, bringing confusion and confusion to users. From the perspective of actual monitoring applications, network access not only requires the access of network videos, but also better management of videos.

The management of general network cameras should include the following functions: support for configuring the encoding parameters (resolution, bit rate, frame rate, etc.) and video input signal parameters (brightness, contrast, chroma, saturation, etc.) of encoding devices such as network cameras through the network; support for configuring motion detection (motion detection area, sensitivity), alarm signals (deployment time, signal type), and video masking (masking area, sensitivity) of front-end network devices; support for receiving and linking various alarm information of front-end network devices; support for pan/tilt control of network cameras and network dome cameras.

That is, we also need to realize that hybrid DVR should not only be satisfied with the access and storage of network cameras, but also realize the management of network videos. This point is also the part that is easily overlooked when choosing a product.

Otherwise, compared with mature analog systems, online video applications will be greatly discounted and it will be difficult to truly impress users.

Network camera access and forwarding capabilities

The first thing to note is the access capacity of the network camera, that is, how many 1080p HD access channels and how many 1080p HD remote preview channels can be simultaneously supported. This point is relatively easy to understand. However, the network throughput capacity of the hybrid DVR must also be considered.

High-definition network video occupies a lot of network bandwidth. One channel of 1080p video usually requires 6-8Mbps network bandwidth, and one channel of 720p video usually requires 3-4Mbps network bandwidth. Taking a 16-channel hybrid DVR as an example, 16 channels of 720p and 8 channels of 1080p network video access to network cameras require 64M access bandwidth. Forwarding one channel separately also requires at least 64M access bandwidth. In addition to the 16 analog channels, the network output also requires 32M, that is, 160M bandwidth throughput is required. In actual applications, the network output of hybrid DVRs is often more than one channel per channel, which also puts forward higher requirements on bandwidth throughput. That is, in the selection of hybrid DVRs, it is necessary not only to pay attention to the access capability of network cameras, but also to confirm the network throughput capability of hybrid DVRs.

Product promotion improvement direction:

Compatibility of network equipment access

At present, it is also a problem that must be solved in the promotion of network video surveillance. First of all, due to the different network communication protocols of various manufacturers, most manufacturers' hybrid DVR systems can only be compatible with their own brand of network cameras, or the compatible brands are limited, which will undoubtedly hinder the development of the market, especially in phased construction or system transformation projects. In addition, in terms of video and audio encoding and decoding, there are also obstacles due to different encoding methods.

Although the mainstream encoding algorithms at home and abroad are H.264 and MPEG-4, the same encoding method may have different code stream encapsulation and encoding levels. It still requires manufacturers to spend a lot of work to achieve unified access and compatibility of network devices. Although the standard protocol organizations ONVIF and PSIA are committed to solving the standard issues of communication protocols, due to the relatively imperfect definition of the protocol, they can only meet the access of basic functions and are still slightly insufficient. At the same time, since each manufacturer has a different understanding of the standard protocol, how to better achieve the compatibility of network coding equipment has also put forward higher requirements for hybrid DVR manufacturers.

Network security

In terms of network security, network video surveillance systems often use network cameras and network dome cameras, which will inevitably lead to the problem of private network address leakage, and the security of video code streams is also questioned. How to avoid and how to ensure the security of network code streams also require hybrid DVR manufacturers to consider and improve.