Difference between NVR, HD-SDI DVR, HVR, DVR, HDCVI

Introduction to NVR

Network video recorder (NVR) is advanced video recorder which is designed to record compressed video footage to hard disk drivers (HDD). The NVR can receive the video/images or even audio through an Ethernet network (cat5/cat6) from IP cameras. Typically, NVR can support high definition recording including 1280x720 (720P) and 1920x1080 (1080P), some advanced NVRs with capability to record 3 megapixel and 5 megapixel resolutions for ultra HD video surveillance applications. Therefore, when compared to a DVR and analogue cameras system, an NVR and IP cameras is more expensive, however, it provides much higher resolution and superior image qualities.

Since the NVR need to record the HD video footage, majority of NVRs are equipped with e-SATA interface which is used to extend the unlimited storage space. Additionally, with HDMI video output to work with HDTV or HD monitor. Moreover, without extra audio cable, the NVR can do two-way communication which can be used for audio broadcasting, as well as performing remotely configuration to the IP cameras.

Currently, there are two major standards for IP surveillance; Onvif and PSIA. Making sure to get the NVR with either Onvif or PSIA compatibility. Since NVR doesn't compress the video footage, a typical NVR can support much more channels which can be up to 64CH.

You may find some PoE NVRs with PoE integration. Power over Ethernet technology can achieve centralized management system which allows IP cameras receive power supply from NVR through single Ethernet cable. A PoE NVR and PoE IP cameras are perfect IP system which can reduce installation cost and allow users to setup a hassle-free system.

What’s HD-SDI DVR?

High Definition Serial Digital Interface (HD-SDI) is another standard interface which complied with SMPTE 292M standard. The HD-SDI DVR can be used as video footage recorder for HD-SDI cameras. With the compliance of SMPTE (Society of Motion Picture and Television Engineers) 292M standard, the camera can deliver uncompressed 720P or 1080P resolution video over at least 100 meters using standard RG59 coaxial cable.

Hence the traditional CCTV system is using same standard coaxial cable for video transmission, this allows user to upgrade their existing CCTV systems with HD-SDI equipment without having to re-install cables. However, the HD-SDI with its own standard, that means the HD-SDI DVR doesn't support traditional analogue cctv cameras. Due to the hardware limitations, only 4 channels and 8 channels HD-SDI DVRs are available in the market, it’s hard to find the 16CH or even 32CH HD-SDI DVR.

Introduction to hybrid video recorder

A hybrid video recorder (HVR) is another type of video recorder which is used to record video from both analogue and digital formats. It can work with analogue cctv cameras and IP cameras. Therefore it has both analogue BNC inputs and RJ45 internet interface for working with IP cameras. HVR can bring flexibility to your video surveillance systems, you can use your existing analogue security cameras, at same time expanding your system to IP system through using HVRs and IP cameras. That means you can keep the standard quality system while expanding the system with megapixel resolution IP cameras.

Traditional digital video recorder

A digital video recorder (DVR) is widely used video recorder for video footage recording. Since DVRs have very mature technology and affordable price, it’s one of major used security recorder in security & protection industry. Similar to HD-SDI DVR, the traditional DVR also receives the uncompressed video footage from analogue cctv cameras, then recording to hard disc drivers (HDDs). DVR has advantages of easy to install and offering cost effective solution. Unfortunately, it has limited recording capabilities, the maximum recording resolution is 960H (960x480) resolution. A DVR and analogue cameras system is very suitable for small video surveillance applications.

What's HD-CVI DVR?

HD-CVI is the abbreviation of High Definition Composite Video Interface, which is in-house technology from Dahua. This is a new technology and standard which provide another alternative for high definition video surveillance. The HD-CVI technology can achieve 720P and 1080P analogue video resolution which solved the resolution limit to analogue CCTV security industry for many years. Currently, the highest resolution is 960H (960x480) for analogue CCTV cameras. Besides the high resolution, the connection between HD-CVI cameras and HD-CVI DVRs can be up to 1600 feet away without visible degradation in video quality.