Ajhua Basic Knowledge of Video Surveillance System User Manual

Basic Knowledge of Video Surveillance System

CONTENT

1

2

6

3

4

5

Camera Introduction

System General Introduction

Recorder Introduction

Transmission Introduction

Display Introduction

VMS Introduction

Page3

Copyright © 2017 Dahua Technologies Co., Ltd. All rights reserved.

Remote System – Topology

Legend

Coaxial Cable

Network Cable

Audio Cable

Data Cable

HDMI

HDCVI Recorder

HDCVI Camera

HDCVI PTZ

Pickup

Sensor

NVR

IP Camera

IP PTZ

Pickup

Button

Storage

Client

Controller

Management
Platform

TV Wall

HDCVI Monitoring

IP Camera

IP Monitoring

IP Monitoring

Monitoring Center

Network

Product Selection Overview

1. Camera

Selection

2. Recorder
Selection

4. Display
Selection

5. VMS

Selection

3. Transmission

Selection

Camera

Accessories

Recorder

Accessories

Transmission

Accessories

Display

Accessories

VMS Accessories

CONTENT

1

2

6

3

4

5

Camera Introduction

CCTV General Introduction

Recorder Introduction

Transmission Introduction

Display Introduction

VMS Introduction

Camera Selection Overview

– The Installation Environment

• Angle of view, Focal length, DORI Distance, Light condition, Protection, etc.

– The Image Quality

• Lens, Sensor, Resolution, Frame rate, Image processing, etc.

– The Appearance

• Bullet, Dome, etc.

– The Interface

• Audio, Alarm, SD card, etc.

– The Intelligent Video Analysis

• IVS, Face detection, etc.

Camera Working Principle

• The working principle of camera is similar to the human vision system.

• It is mainly composed of three parts: the lens, the sensor, and the processor(DSP,ISP).

Human Vision System

Retina

(Feel the light and imaging)

ISP

DSP

Camera

Lens

(Cornea+Pupil+Lens)

Sensor

(Retina)

Processor

(Brain)

Brain

(Control, Analysis)

Cornea+Pupil+Lens

(Focus the light to retina)

Camera – Sensor Type

• Common sensor type: CMOS, CCD.

– CCD: image effect is better, but the power consumption is large, and wide dynamic performance is poor,

and the price is higher.

– CMOS: high integration, and price advantage is very obvious, and wide dynamic performance is good.

Sensor Type

Power

consumption

Illumination effect

Dynamic Range Price

CCD Large Better Bad High

CMOS Small Normal Better Economical

Camera – Lens Focal Length & Angle of View

Manually adjust the focal length
adjustment ring.
WIDE (W)<-->TELE (T)

It’s convenient for installation.

Fixed focal length camera
always be installed in a fixed
scene and the target object is

in a fixed area. (e.g. 8.5mm)

Zoom camera supply power for
motorized lens

The focal length can be adjust

by motor remotely in operation
menu to realize optical zoom
in/ zoom out

Fixed Lens

Focal Length

Distance

f=2.8mm

WIDE (W)

f=3.5mm f=8mm f=30mm

TELE(T)

2m

Varifocal Lens

Motorized Zoom Lens

Lens focal length can be
searched in specifications:

E.g. The lens is motorized zoom lens, 7mm~35mm(35/7=5x optical
zoom). When the focal length is 7mm, the Angle of view is
H(horizontal) 38°, V(vertical) 22°. When the focal length is 35mm,
the Angle of view is H(horizontal) 14°, V(vertical) 8°.

Why the FOV-H is different from FOV-V? Because the sensor is

rectangle, not a square.

Camera – Lens Focus

• The focus function can make the light focused to give the clear object imaging on the sensor.

Manually adjust the focus
adjustment ring
NEAR (N)<-->FAR (∞)

FAR too much NEAR too muchAppropriate Focus adjustment

Manual Focus

Motorized focus camera supply
power for motorized focus lens
The focus can be controlled

remotely in operation menu

Motorized Focus

Lens Focus mode can be searched in specifications:

Camera – Iris/Aperture

• The lens Iris can control the light which get through the lens so that images can be sharp, clear and correctly

exposed with good contrast and resolution. Generally speaking, the larger aperture opening means the

camera has better anti-shake performance.

OPEN too much CLOSE too muchAppropriate Iris adjustment

Manually adjust the Iris
OPEN (O)<-->CLOSE (C)

Manual Iris

Auto iris camera supply power for auto Iris lens

The iris can be controlled automatically to adapt
for different environment.

Auto Iris

Fixed Iris

The PFA (Predictive Focus Algorithm) adopts Dahua newly-developed focus algorithm, which ensures the
camera image stays focused while zooming, and greatly improves user experience and enhances product
value.

PFA

Camera – Different F-number Effect

• F-number = focal length / diameter of aperture.

– The smaller f-number, the larger aperture opening, the higher brightness, need less shutter time, and the

narrower depth of field, give the more contrast of the clear and vague.

F-number

Larger

Depth of field

Lower

Higher

Aperture opening

Smaller

Wider

Narrower

Lens F-number can be searched in specifications:

 Camera Video Performance

 Resolution

 DORI distance

 BLC/HLC/WDR

 White Balance

 ICR

 Low-light picture performance

 Protection

 …

Camera – Resolution

• A camera’s resolution is defined by the number of pixels in an image provided by an image sensor.

• The higher the resolution of the lens and sensor, the clearer the picture, the larger the output image size.

(Generally, the lens resolution should be larger than sensor so that the sensor performance won’t be

wasted.)

• Common resolution: CIF, D1, 960H, 1M (720P), 1.3M, 2M (1080P),3M, 4M, 4K.

Resolution

Pixels

960H

960

*576P (480N)

1M

(720P)

1280*720

2M

(1080P)

1920*1080

4M

2688*1520

4K

3840*2160

Camera – Resolution Comparison

• You can get more detailed information in a higher resolution picture even you

zoom in the picture in digital zoom mode.

– Digital zoom means enlarging the particular sections of a high-resolution image.

4K Camera 1080P Camera

Lens resolution can be searched in specifications:

Camera – DORI Distance

• The DORI distance is to define the camera Detection/ Observing/ Recognition/
Identifying capability. It’s useful in camera selection and installation guide.

If you want to realize

___________ the object

You need the min. object size in the picture

Detect

25PPM (Pixel Per Meter)

1 meter object in the picture correspond to at least 25 pixels to make the camera detect it. (E.g.

Realize motion detection to trigger the alarm)

Observe 63PPM

Recognize

125PPM

(E.g. Realize license plate recognition)

Identify

250PPM

(E.g. Realize face features identifying)

 E.g. A camera DORI distance is show as follows:

 The camera focal length can be adjusted from 2.7mm(W--WIDE) to 13.5mm(T--TELE).

 If you adjust the camera focal length as 2.7mm, the object in 46/18/9/5 meters away from the camera can be detected/observed/recognized/identified.

Camera – BLC/HLC/WDR

• Sometimes the environment is complex such as backlight environment, and the pictures do work

well. So we need do some compensation for these application scenario.

• We can select the compensation mode for different requirements: BLC for backlight environment,
HLC for spotlight environment, WDR for a scene with a large difference between light and dark,

etc.

– Note: If we select the BLC mode of a camera, we can’t use HLC/WDR mode at the same time. The

function is switchable for different application scenarios.

Camera – BLC

• BLC (Back Light Compensation) technology is to enhance the picture brightness so that we can

see the object even in back light.

BLC off

BLC on

Camera – HLC

• HLC (High Light Compensation) can reduce the brightness of the entire to suppress the strong spot in the
picture and use the additional illuminator to make the dark areas get compensation to get a clear image.

This function is often used to see the license plate number at night to suppress the car light effect.

HLC off HLC on

Camera – WDR (1/2)

• WDR (Wide Dynamic Range) cameras often incorporate an image sensor that takes different

exposures of a scene (e.g., a short exposure for very bright areas and long exposure for dark

areas) and combine them into one image, enabling objects in both bright and dark areas of a
scene to be visible.

• WDR does not apply to scenes that move objects quickly.

WDR off

WDR on

Camera – WDR (2/2)

High

shutter speed

Ordinary

shutter speed

Synthetic effect

Combo

 120dB true WDR principle: take 2 pictures (a high light picture to see the dark object, a low light picture to

see the bright object) and combine them to 1 picture.

 140dB WDR camera takes 3 pictures , so we call it ultra WDR, which is better than 120dB true WDR.

Camera – DWDR

• DWDR (Digital WDR) is for the camera which don’t support true WDR. It’s achieved through the internal

DSP algorithm, mainly for the brightness curve to do some correction, the dark curve will be raised and the

bright curve down, such as the right part of the dotted line, the overall effect

• The effect of true WDR is better than DWDR.

Camera – BLC/HLC/WDR

• Sometimes the environment is complex such as backlight environment, and the pictures do work

well. So we need do some compensation for these application scenario.

• We can select the compensation mode for different requirements: BLC for backlight environment,
HLC for spotlight environment, WDR for a scene with a large difference between light and dark,

etc.

– Note: If we select the BLC mode of a camera, we can’t use HLC/WDR mode at the same time. The

function is switchable for different application scenarios.

Camera – Color/Black and White

• The camera can be switched in Day/Night mode.

– In the day mode (color mode), the camera will give you a color picture.

– In the night mode (black and white mode), the environment is dark, the color effect is poor, so the camera will give

you the black and white picture to see the object clear.

– The camera DSP can switch the color/black and white mode automatically that the camera can judge whether it’s

day or night by analyzing the picture brightness or using the photo resistance to sense the environment brightness.
Also we can switch the color/black and white mode manually in operation menu.

Analyze the picture brightness

using the photo resistance to sense

the environment brightness

Day(C

olor)

Night(Black

White)

Day/Night info can be searched in specifications:

Camera – ICR

• The sensor can sense the infrared light so that the picture will look red and purple. The camera can use the

ICR dual filter to solve the problem.

• The ICR dual filter consists of an Infrared Cut-off Removal filter and a full spectrum optical glass.

– Day: The infrared cut-off filter works, the IR light will be cut, so the sensor restores the true color.

– Night: The environment is dark, there’s little visible light, camera will switch into the black and white mode, The DSP

will remove the infrared cut-off filter and make full-spectrum optical glass work to pass the infrared light through so
that the sensor takes full advantage of all the light, thus greatly improving the low-light performance.

ICR (color) ICR (night)

Camera – Low-light Performance

• In the night, Low illumination makes the camera difficult to focus, the image will be blurred and dark. To

solve the problem, we will take some method to improve camera low-light performance:

– Use a lens with large aperture, and use low speed electronic shutter to make more light pass through.
– Use a big sensor and improve the sensor performance to sense more light.

– Use the AGC technology to amplify the electric signals.

• We will use the min. illumination value(Lux as unit) to judge the camera low-light performance. The lower

the Lux value, the better the camera's sensitivity.

Low-light info can be searched in specifications:

Camera – Starlight Technology

• The Starlight Technology can improve the camera low-light performance and make it deliver usable video

with minimal light. The starlight camera presents high quality colorful image with rich details even under

extreme lowlight environment (less than 0.01lux).

Snapshot by starlight Camera Photo taken by IPhone6S

Camera – Noise Reduction

• In preview, signal and noise exist at the same time. through the DNR (Digital Noise Reduction)

technology can inhibit the noise in the screen, then obtain better quality images.

– 2DNR works by analyzing individual frames of video, identifying algorithmically and correcting those

pixels that likely represent noise. 3DNR additionally analyzes the differences between successive frames

in order to adjust pixels and improve fidelity.

3DNR off 3DNR on

Camera – IR Camera

• IR camera means that the camera with built-in IR illuminator. When the environment is too dark, the

camera will turn on IR light automatically according to the photosensitive resistance feedback signal and

the camera will provide more details in the black and white mode.

– The luminescence conversion efficiency of IR is fixed. The Larger the IR angle, the shorter the IR distance.
– E.g. The following image shows the effect of IR (when the IR distance is 100m).

IR info can be searched in specifications:

Camera – Smart IR

• Sometimes, the picture will have the centralized overexposure problems because the object is near and all

the infrared lights work together. The smart IR technology can detect the brightness change of IR light by

the advanced DSP algorithms, to avoid the centralized overexposure problems.

General IR Camera Smart IR Camera

Camera – Protection

• Sometimes, the camera installation environment is bad, so we need some protection for the cameras.

– E.g. The outdoor camera need water proof to avoid the water from rain, dust proof to avoid the environment dust

and wide working temperature range to avoid hot/cold weather.

– Some protection have the certificated grade so that we can know the performance of the camera for different

installation environment.

Protection info can be searched in specifications:

Camera – Protection

IP 6 7

Ingress Protection

Dust Proof Level

Water Proof Level

Dust

Proof

Level Description

0

No protection against contact and ingress of objects

1

Any large surface of the body, such as the back of a hand, but no

protection against deliberate contact with a body part

2

Fingers or similar objects

3

Tools, thick wires, etc.

4

Most wires, slender screws, large ants etc.

5

Ingress of dust is not entirely prevented, but it must not enter in

sufficient quantity to interfere with the satisfactory operation of
the equipment.

6

No ingress of dust; complete protection against contact

(dust

tight).

A vacuum must be applied. Test duration of up to 8 hours

based on air flow.

Water

Proof

Level Protection against

0

None

1

Dripping water

2

Dripping water when tilted at 15

°

3

Spraying water

4

Splashing of water

5

Water jets

6

Powerful water jets

7

Immersion, up to 1

m depth

8

Immersion, 1

m or more depth

9

Powerful high temperature water jets

Outdoor Scenarios Requirement : ≥IP65

Camera – Protection

IK 10

Impact Protection Vandal Proof Level

Vandal Proof

Details IK10

Impact energy (joules) 20

R mm (radius of striking

element)

50

Material steel

2

Mass kg 5

Pendulum hammer Yes

Spring hammer No

Free fall hammer Yes

Vandal Resistance means the housing protect device against mechanical collision.

Camera – Protection

• Special Housing

– Adapt to the installation requirements of different environments.

Anti-Explosion

Anti-Corrosion

 Camera Interface

 Video

 Audio

 Alarm

 Power

UHD video

Audio

Control data

P WER

Camera – Video

• Video: made up of continuous pictures for a time.

– 1 picture in the video is called a frame.

– Frame Rate (FPS) → Frames per second Higher Frame, more fluent video, more realistic

Frame 1

Frame 2

Frame 3 Frame 4 Frame 5

1s Video

Frame rate: 6fps

Frame 6

Interval 0.2s 0.2s 0.2s

0.2s 0.2s

Frame 1 Frame 2 Frame 3

1s Video

Frame rate: 3fps

Interval 0.5s 0.5s

Camera – Video Standard

• The camera video standard can be set as PAL mode or NTSC mode.

– PAL (Phase Alternating Line)

• Used in the countries whose power frequency is 50Hz.

• We should set the camera video standard mode as PAL in China, Russia, Europe, Egypt, etc. Otherwise the video will flicker and

out-of-step.

– NTSC (National Television System Committee)

• Used in the countries whose power frequency is 60Hz.

• We should set the camera video standard mode as NTSC in USA, Japan, etc. Otherwise the video will flicker and out-of-step.

• Generally, the frame rate should be more than 25fps(PAL—in China, Russia, Europe, Egypt), or

30fps(NTSC—in USA, Japan), can realize the real-time effect that the video looks continuous and fluent.

Camera - Analog Camera Video Output

• The ANALOG system always use the coaxial cable to transmit the analog video signal.

Coaxial cable(point to point connection-camera

connect with recorder directly)

Recorder Display

Dahua HDCVI Cam

(Up to 4K resolution)

Traditional Analog Cam

(Up to 960H resolution)

Camera - Network Camera Video Output

• The NETWORK system always use the network cable to transmit the digital video stream.

IPC

NVR Display

IPC

Network

IPC: Network Camera

NVR: Network Video Recorder

Network cable(the device

connect with switch)

Page41

Copyright © 2017 Dahua Technologies Co., Ltd. All rights reserved.

Analog System Features

 No Delay

 As analog system, HDCVI can present

vivid image quality without delay.

 Lossless

 Without encode/decode process, no

image loss of preview

 Data Security

 As analog system, HDCVI can best

prevent cyber-attacks

HDCVI

IPC

HDCVI Recorder

NVR

HD image

Blur image

P2P

transmission

Video encoding

The 2ndvideo processing

& encoding/decoding

The 2ndvideo decoding

HDCVI Follows analog system advantage features

Camera - Network Camera Video Stream

• What is stream?

– It’s the compressed image data, used to evaluate video data volume in an instant time. The stream unit: Bit Rate (bps -- bit

per second)

– Higher resolution, higher frame rate means more data and greater stream

– Stream Type: Video Stream, Audio Stream, Composite Stream(Video Audio)
– Some IPC can give more than 1 video stream in different resolution for different device, such as PC, Mobile Phone.

• Why we need compress the image data?

– Reduce data volume to realize convenient transmission and storage, and save the storage space. (E.g. 1MB file transmission

and storage need less time and space than 1GB file)

• How to compress the image data?

– Use the encoding technology. (H.264, H.265)
– Use the stream control technology. (CBR, VBR)

Stream info can be searched in specifications:

Video Encoding Technology

• H.264 Compression(international standard) take the difference between the former and the latter

pictures into consideration, and only compress the changed part. If there’s a small rectangle moves, H.264

will record the direction and distance, and the rectangle itself will not be compressed twice.

Object

P FrameI frame

Motion

Vector

Searching

Area

Correspon
ding
Object

Compression info can be searched in specifications:

Noise Suppression Technology

• Adopts different noise reduction levels

Video Encoding Based on the Video
Contents Analytics

• Dynamic ROI(Region of Interest) & dynamic GOP(Group of Pictures)

• Flexible reference frame structure

Video Encoding Technology

• H.265 Compression(international standard) is better than H.264 with higher compression rate.

• Smart H.265+ Compression(proprietary standard) is intelligent encoding algorithms developed by

Dahua technology based on H.265. (Smart codec, lower bit rate, less storage)

H.265+

HD

D

90%

H.264

HD

D

FULL!

H.265

HD

D

50%

01

02

03

Advanced Bit Rate Control Algorithm

• Scene adaptive encoding strategy

Stream Control Technology

• We can set a referenced stream value so that the encoding processor will adjust the compression

rate to control the stream in the required range.

– E.g. For indoor scenes, due to less moving objects, the configuration stream is 2Mbps to meet the requirements. For

road monitoring scenarios, due to the scene changes, you may need to configure the bit rate to 4Mbps.

• We can set different stream type for different application scenarios.

– CBR(Constants Bit Rate) means the stream will be controlled in a constant range.

• Advantage: The stream is steady.

• Disadvantage: The picture quality will go down when the video has a lot dynamic information.

– VBR(Variable Bitrate) means the stream is variable according to the video dynamic information.

• Advantage: The picture quality is good even the video has a lot dynamic information.

• Disadvantage: The Stream will be large and need more storage when the video has a lot dynamic information.

Stream control info can be searched in specifications:

Camera – Audio

• Sometimes, when we look at the video, we need the audio information to know what happened.

– E.g. At the retails checkout counter, in the lift, in the meeting room, etc.

• The camera audio function can be realized by several modes: Camera connect with the pickup; Camera with

a built-in mic.

• The audio signal can be output with the video signal, which called composite stream.

Built-in mic camera always be used in the
small room or where the camera is nearby
the sound source.

Built-in Mic

Pickup always be used in the big room or
where the camera is not nearby the sound
source.

Pickup Connection

Audio Interface info can be searched in specifications:

Camera – Audio Output

Traditional Audio

Broadcast Quality Audio

IPC

Video + Audio

Network

Analog Camera

Video + Audio(Broadcast Quality Audio)

Note: In the analog system market, only the Dahua

HDCVI camera support audio coaxial transmission

Camera Audio

Output Interface

Recorder

Monitor

Speaker

Camera – Alarm

• Sometimes, when we look at the video, we need the alarm information to warn us what happened.

– E.g. At the chemical plant, in the safeguard system, etc.

• The camera alarm function can be realized by several modes: Camera analyze the video to give the alarm

signal; Camera connect with the alarm detector; Camera with built-in alarm sensor.

• The alarm signal can be output with the video signal.

Alarm sensor always give the additional

information that we can’t get from the

video.

Alarm Detector Connection

The camera can detect some exception
event by video analysis, such as motion
detection.

Video Analysis

IoT camera is very convenient for alarm
and video monitoring because of the built-

in sensor.

IoT Camera (Built-in Sensor)

Alarm Interface info can be searched in specifications:

Camera – Alarm Output

IPC

Network

Analog Camera

Video + Alarm

Camera Audio

Output Interface

Video + Alarm

Recorder

Monitor

Siren

Camera – Power Input

• The camera need power to start work.

• Generally, we have several modes to supply power for camera: Power adaptor( Some camera support

12VDC input; Some camera support 24VAC input); PoC(Power over Coax)/ PoE(Power over Ethernet) power

supply, which can make installation more convenient and save the labor cost.

• If we use the power adaptor for different cameras, please pay attention for these notes:

– The power adaptor output voltage(unit: V) should be the same as the camera input, otherwise the camera may be

damaged.

– The power adaptor output power (unit: W)(the product of voltage and current(Unit: A)) should be more than the

camera power consumption, otherwise the camera may can’t work normally.

Power supply info can be searched in specifications:

Camera – Power Input

IPC

In network system, camera is
supplied power from PoE

switch or recorder through

the network cable

Network

Analog Camera

Note: In the analog system market, the Dahua HDCVI support PoC but the traditional

analog system doesn’t support PoC

Recorder

In analog system, camera is supplied power from

recorder through the coaxial cable

Camera Power

Input Interface

12VDC Power Adaptor 24VAC Power Adaptor

 Camera Categories

 Classified by output signal

 Classified by appearance

 Classified by application scenarios

 …

Camera - Categories

• In the video surveillance industry, we have traditional analog camera, traditional SDI camera, HD analog

camera, network camera, etc.

– Traditional analog camera/SDI camera use the coaxial transmission, the resolution is low, so they’re instead by HD

analog camera and network camera.

– HD analog camera use the coaxial transmission, can easily instead of the traditional cameras. In the HD analog

industry, the HDCVI (up to 4K, developed by Dahua, leading the HD analog development)/ TVI/ AHD(up to 5MP) is
the most used system.

– Network camera use the network transmission, can support higher resolution and more intelligent functions, can

realize convenient system expansion.

PTZ Cam

Mobile Cam

Eyeball

Dome Cam

IR Bullet Cam

Box

Cam

Speed Dome

Cam

Vandal-proof

Dome Cam

Camera - Appearance

Panoramic Cam

Small

PIR IoT

Parking

lot

Camera - Application Scenarios

Entrance

Corridor

Corner

Panoramic

ATM

PIR

Long Distance Monitoring

Camera Calculator – Tool Use

• Use the Camera Calculator Tool to help the camera
installation and deployment.

– Select the Camera Type

Camera Calculator – Tool Use

• Use the Camera Calculator Tool to help the camera

installation and deployment.

– Select the Camera Model->Set the Installation parameters to see

the result.

Camera Calculator – Tool Use

• Use the Camera Calculator Tool to help the camera

installation and deployment.

– Select the Camera Model->Set the Installation parameters to see

the result.

PPM Introduction

2D View

3D View

Image View

CONTENT

1

2

6

3

4

5

Camera Introduction

CCTV General Introduction

Recorder Introduction

Transmission Introduction

Display Introduction

VMS Introduction

Recorder Selection Overview

– The Signal type

• NVR (only for IP system), HCVR/XVR (IP, HDCVI, CVBS, TVI, AHD), etc.

– The Signal resolution

• 4K@15fps, 4M@30fps, etc.

– The HDD capacity

• The video stream size, the record time, etc.

– The Interface

• Audio, Alarm, USB, Network Port, etc.

– The Intelligent video analysis

• IVS, Face detection, etc.

General Recorder Working Principle

• The general recorder include DVR (Digital Video Recorder ) and NVR ( Network Video Recorder ).

– The main function of recorder is to preview/ playback the video and record the video data.

AD

Encode

EncodeAD

NVR

DVR

Network

Analog Camera

IP Camera

Network

DVR Working Principle

• DVR ( Digital Video Recorder ) is suitable for analog system, connected with analog cameras(via coaxial interface).
DVR has video capture, coding compression, recording, decoding, transmission functions, etc.

• Because the DVR support decoding, so it can also connect with network cameras(via Ethernet interface) .

• Dahua DVR called XVR.

Analog Camera

(Preview)

Video Capture

Coding Compression

Network Surveillance

(Preview)
Decoding

Display

(Playback)

Decoding

Network

Web DSS

IPC

Real-time Preview

Real-time Recording

Real-time Playback

Recording

• NVR ( Network Video Recorder ) is suitable for network system, connected with network cameras(via

Ethernet interface) . NVR has recording, decoding, transmission functions, etc.

• Because the NVR don’t support encoding, so it can NOT connect with analog cameras.

NVR Working Principle

(Preview)
Decoding

Display

(Playback)

Decoding

Network

Web DSS

IPC

Realtime Preview

Realtime Recording

Realtime Playback

Recording

 Recorder Video Management

 Device Management

 Video Preview

 Video Storage

 Video Playback

Recorder – Device Management

• A recorder can connect with several cameras so that realize a local management system, so we can monitor

more than 1 video at the same time.

– For the DVR, it can support analog camera & IPC input.
– For the NVR, it can only support IPC input.

– We use “channel” to define the device number.

DVR device input capability can be searched in specifications:

NVR device input capability can be searched in specifications:

Recorder – Video Preview

• For the DVR, the analog video signal from camera can be convert to VGA/ HDMI signal to display on the

screen directly without encoding/ decoding. No compression means less resolution loss and no delay. So

the DVR and analog system always be used in casino, sports broadcast scenarios.

• For the NVR, the network video signal will be decoded and display on the screen. The decoding technology

should be the same as encoding.

– E.g. If the NVR support H.265 decoding, the camera can use H.265 encoding. If the NVR only support H.264 decoding,

the camera should use H.264 encoding even it can support H.265.

Compression info can be searched in specifications:

Analog Camera

(Preview)

Video Capture

Display

Network Camera

Encoding(H.265)

(Preview)

Decoding(H.265)

Display

Recorder – Video Preview

• The recorder input capability should be better than the camera output performance.

– E.g. If the recorder support 30fps@4MP camera input, the camera output should be set less than or equal to

30fps@4MP even it can support 30fps@4K.

NVR decoding capability can be searched in specifications:

XVR decoding capability can be searched in specifications:

Dahua XVR support penta­brid input (HDCVI, AHD, TVI
is HD analog technology

developed by different

manufacturer)

HDCVI

CVBS

IPC

AHD

HDTVI

Recorder – Video Storage

• For the DVR, the analog video signal should be convert to digital signal by A/D module and compressed by

encoding technology, then the data can be recorded in the HDD. The encoding technology has been

mentioned before in the camera introduction.

• For the NVR, the network video signal has been encoded in the camera, so the video stream can be

recorded in HDD directly.

NVR/ XVR recording capability can be searched in specifications:

The video can be recorded

manually, automatically

(continuously or triggered by some
event)

Recorder – Local Video Storage

• The video is always recorded on the HDD.

– In video surveillance industry, the video will be recorded frequently, so we should use the surveillance HDD instead

of the PC HDD, to make the recording stable and reliable.

– The HDD capacity, size, interface should match with recorder.

– More cache memory means better HDD performance.

• Also we can select the SSD as storage medium.

– Less noise, higher reading/writing rate, higher antiknock performance.

NVR/ XVR HDD compatibility can be searched in specifications:

Recorder – Network Video Storage

• Besides the internal HDD storage, the network storage is always used in some project because the network

storage can realize large capacity, high data security, good Read/Write performance.

– There are many ways to realize network storage: DAS (Direct Attached Storage)/ NAS (Network Attached Storage)/

SAN (Storage Area Network)/ Could Storage.

EVS

010110011010110101010101000001110010101010010101000110101011110001010101

Network Video Transmission Technology

(ONVIF/PSIA/RTSP/iSCSI )

Professional network storage

Recorder – Cloud Video Storage

• Consumer cloud storage is very convenient for consumers to monitor the video anywhere from cloud via

network without HDD installation.

• Professional cloud storage is very convenient for big project to realize higher performance and reliability.

Home & SME Cloud Surveillance

Web-based cloud storage and video
services, a new profit recourse for SIP

Safe City Cloud Surveillance

Massive storage capacity with high
availability and efficiency

Intelligent Traffic Surveillance

Combined with cloud structured analysis,
enabling fast vehicle and individual targeting

Recorder – Video Storage Capacity

• The video storage capacity depends on the channel number, video stream per channel and the storage

duration.

– The HDD capacity unit is TB.

• 1TB=1024GB，1GB=1024MB，1MB=1024KB, B(Byte) = 8bit, bps = bit/s

Code format

Resolution

Bit Rate

Video

Compression

Bit stream size (ma

x)

960H

960*576

25/30

fps

H.265

1Mbps

720P

1280*720 1Mbps

1080P

1920*1080 2Mbps

4MP

2688*1520 4Mbps

4K

3840*2160 8Mbps

Storage capacity per channel s (unit TB)

Video stream per channel v(unit Mbps)

Video recording day d

Video recoding hour per day h

The calculation is as following:

s = v÷8×3600×h×d÷1024÷1024 (reference only)

v÷8 Mbps-->MBps, ×3600×h×d MBps--> MB, ÷1024÷1024 MB-->TB

Then we can calculate the HDD quantity we need.

How to know the video storage capacity?

How to know the video stream per channel?

It’s related to the resolution, bit rate, video compression (reference only)

Recorder – Video Storage RAID Technology

• RAID(Redundant Array of Independent Disks)

technology combine several disks as a disk group to make

the storage more stable, faster and realize data redundancy.

– There are many different RAID technology for different

combination of disks.

– Redundant data can help user to retrieve the data when

some HDDs got broken to make data safe.

– RAID has better storage performance than single disk.

RAID

RAID 0 RAID 1 RAID 5

RAID 6

RAID 10

Some recorder support RAID0、RAID1、RAID5、RAID6、RAID1 and one-key setup

RAID info can be searched in specifications:

Recorder – Video Storage RAID Technology

• RAID0 (Stripe)

– RAID0 combine all the disks and do

virtualization but without redundancy

check, which makes the whole system with
great performance but unable to afford
the risk of destroy of disk. RAID0 capacity

is the total of disk capacity.

• RAID1 (Mirror)

– RAID1 copies all the data from one disk to

another, which makes the data absolutely
stable but the user ratio lower and the
storage cost higher.

RAID 0

RAID 1

 RAID5

 Support proper functioning when one disk doesn’t work. Use ratio is

high (N-1), Read/Write Speed is fast. RAID5 is most common used RAID
level.

 Q: How many HDD to set RAID5?

---A: At least 3 HDDs.

Also we can set hot spare HDD to make the RAID group work more reliable.

Private hot spare is spared for the one RAID 5 group and the public hot
spare is spared for all the RAID 5 groups.

Recorder – Video Playback

• Sometimes, if something happened and we need playback function to find the evidence from the recorded

video. Some recorder support multi playback mode for different requirements.

• The recorder will decode the storage data and then convert to the VGA/HDMI signal to display on the
screen.

Display

(Playback)

Decoding

External storage

(eSATA, USB disk)

Playback info can be searched in specifications:

 Recorder Interface

 Video

 Audio

 Alarm

 PTZ Control

 Debug

 Power

NVR

XVR

Recorder Interface Overview

Recorder - Video Input

• XVR connect with HD analog cameras directly

via BNC interface. XVR connect with IPC via

Ethernet interface.

Ethernet interface

Network

PoE Ethernet interface

NVR

 NVR connect with network

cameras via Ethernet interface. If

the NVR support PoE output, the
IPC can connect with the NVR

PoE Ethernet port directly to

realize plug&play.

XVR

BNC Video Input

Network

Recorder - Video Output

• Recorder use the VGA/ HDMI port to display the

video on screen.

– HDMI can transmit the video with audio together but

the VGA can only transmit video signal.

– HDMI support higher resolution than VGA.

VGA Video Output

HDMI Video Output

Display info can be searched in specifications:

Recorder - Audio Input

• There are several audio input mode:

– The audio signal can be input together with video signal from the camera.

– The audio signal can be input individually from the RCA audio input port.

RCA Audio Input

Audio input info can be searched in specifications:

Recorder - Audio Out

• There are several audio out mode:

– The audio signal can be output together with video signal from the HDMI output to the screen which with built-in

speaker so that we can combine the video and audio signal to know what happened.

– The audio signal can be output individually from the RCA audio output port.

RCA Audio Input

Audio output info can be searched in specifications:

Recorder - Audio Two-way Talk

• The recorder can support audio input and audio output, and the recorder can realize two-way talk with web
manager or platform via network for communication.

• The two-way talk function is always used for different security staffs.

Network

Two-way Talk

Recorder - Alarm Input

• The recorder can manage the alarm signals, the input alarm signals can be used to trigger recording, alarm
out, etc. There are several alarm input mode:

– The alarm signal can be input together with video signal from the camera.
– The alarm signal can be input individually from the alarm input port.

• There are two types; NO (normal open)/ NC (normal close). If the alarm input device use external power, the device and the

NVR should the same ground.

Alarm input info can be searched in specifications:

Alarm input port

NO: Normal Open

Normal

Abnormal

NC: Normal Close

Normal

Abnormal

Recorder - Alarm Output

• The recorder can manage the alarm signals, it can be triggered by alarm in, video analysis, etc. There are
several alarm output mode:

– The alarm signal can be output individually from the alarm output port.

• Some recorder only output a passive signal, so we need supply power for the external alarm device.

• NO：Normal open alarm output port.

• C：Alarm output public end.

Alarm output info can be searched in specifications:

Alarm output port

Recorder – Power Input

• The recorder need power to start work.

– For some light models with less HDDs, we always use the DC power input. For some big models with more HDDs, we

always use the AC power input.

– When we select power adaptor, we should consider about the input voltage. The voltage should in the support range

of the device, otherwise the power will damage the device.

– Also we should consider about the power consumption. The recorder itself need power, the installed HDDs also need

power supply, and the PoE output need power supply. So the recorder with more HDDs and more PoE device

connections need more power consumption( more current). If the current is not enough, the device can’t work

normally.

Power supply info can be searched in specifications:

Recorder – Power Output

• The recorder can supply power for the cameras via PoE/PoC or some power output port, which can make
installation more convenient and save the labor cost.

• If we use the recorder supply power for cameras, please concern about the limitation of output

consumption: DO NOT exceed the limitation, otherwise it may damage the recorder.

PoE Power output info can be searched in specifications:

PoC Power output info can be searched in specifications:

PoE camera connection is via individual PoE port: (Point to
point connection)

PoC camera connection is via BNC port just like non-PoC

camera connection: (Point to point connection)

Recorder Storage Capacity Calculation

• Use the Disk Calculator Tool to help the storage capacity
calculation.

– Install the DiskCalculator Tool in ToolBox

1. Add Streaming: Add channels

2. Select the Channels number, Compression,

Environment, Resolution, Frame Rate, Audio to
calculate the Bitrate

3. Select the Recording Day

4. Click the Calculator button

5. The Request Capacity is as following:

CONTENT

1

2

6

3

4

5

Camera Introduction

CCTV General Introduction

Recorder Introduction

Transmission Introduction

Display Introduction

VMS Introduction

Transmission Selection Overview

– The Interface

• Video interface, Audio interface, Network interface, etc.

– The Transmission Cable

• VGA, HDMI, Coax, Network Cable, etc.

– The Communication Protocol

• HDCVI, Private, ONVIF, etc.

– The Switch

• POE, POE+, ePOE, etc.

BNC&SDI

VGA

DVI' HDMI

Video Cable Introduction

• PS: Please avoid the excessive curve such as fold/twine, which will destroy the cable.

You can obey the vein of cable to tidy them up.

Video Cable – Coaxial Cable

• Impedance 75Ω cable can reach to 500m

• Impedance 50Ω cable can reach to 185m

• PS: the distance in reality due to many factors such as interference and also the consumption lost

Thick (75Ω)

Diameter

Coaxial Cable

Thin (50Ω)

Application

Baseband (50Ω)

Bandwidth (75Ω)

TV analog signal

Digital signal

Transfer BNC SDI VGA DVI HDMI

VGA Converter

Video Cable – VGA

• VGA

– VGA transmission distance is decided by the workmanship. The good cable can reach to 50m and

usually we use VGA extender to get far distance transmission

• Transmission Signal

– Analog signal

• Transmission signal

– Doesn’t support audio

– Different structure decide to

transmit analog or digital signal

Transfer BNC SDI VGA DVI HDMI

DVI

DVI-I

Converter

Video Cable – DVI

 Structure

 DVI-A (12+5) analog signal

 DVI-D (single 18+1 or dual 24+ 1 ) digital signal

 DVI-I (single 18+5 or dual 24+5) analog signal

 PS: DVI-I can change to VGA/BNC , DVI-D can’t change to VGA/BNC

Transfer BNC SDI VGA DVI HDMI

HDMI Converter

Video Cable – HDMI

• HDMI

– digital signal transmission based on TMDS technology, compatible with DVI and support audio

• Material

– High density non-ferrous nylon braided mesh + high quality injection molding iron powder core + double-sided 4-layer aluminum

junction and high density double-layer shielding net + pure copper plating tin anti-oxidation wire core + copper shell gold-plated

15U"

Network Cable Introduction

• Overview

– Network Cable is to connect the network from one network device to another. Network cable is the

basic part of network

• Classification

– Twisted-pair: the most common type of network cable, general cable is twisted pair, and the

transmission distance is 100 m, the theory of maximum distance is 150 m, but and line quality,
especially the crystal head production level has a lot to do

– Coaxial cable: The maximum transmission distance between the transmission distance of 75Ω is 500m

and the maximum transmission distance of 50Ω is 185m

– Optical fiber: transmission distance is 2 – 120KM

Network Cable – Twisted Pair

• Classification

– UTP=Unshielded Twisted Pair

– STP=Shielded Twisted Pair

Video Manage Server

Network Cable – Twisted Pair

• Now most RJ45 device support the automatic flipping function, it means that it will adjust the receive/send

function of the port.

Traditional hundred megabyte network use 4 cables to transmit network. But the thousand megabyte

network, it requires 8 cables.

Type Straight Through cable Crossover cable

TIA/EIA 586A

TIA/EIA 586B

Network Cable – Optical Fiber

• Overview

– An optical conduction tool used to make a full reflection of light in a fiber made of glass or plastic

• Structure

– Fiber core, package layer, coating layer, tight cover

• Classification

– SMF

– MMF

Network Cable – Optical Fiber

• Transmission distance

– MMF (Multi-mode Fiber) 2KM-5KM

– SMF (Single-mode Fiber) 20KM- 120KM

Fiber Attenuation

Coefficient (dB/km)

850nm 1300nm 1310nm 1550nm

Multi-mode 3 1 -- --

Single-mode -- -- 0.3 0.2

 Factors

 The medium used by the transceiver

 The transmitting power of the transceiver

 Sensitivity of receiver

 Wavelength

 Attenuation coefficient

Network Cable – Optical Fiber

SMF

 Transmit one mode light
 Yellow cable

 Wavelength 1310nm/ 1550nm

 Transmission band is wide,
 transmission distance is far

Single mode

MMF

 Transmit multiple mode light
 orange cable

 Wavelength 850nm/1300n m

 Transmission band is narrow
 Transmission distance is short

Multiple mode