Megapixel Networking 101. Why Megapixel?

Transcription

1 Megapixel Networking 101 Ted Brahms Director Field Applications, Arecont Vision Why Megapixel? Most new surveillance projects are IP Megapixel cameras are IP Megapixel provides incentive driving the leap to IP surveillance High resolution of megapixel improves image quality and can reduce cameras needed to cover wide fields of view 1

2 Move to Multi-Megapixel is Accelerating $8,000,000,000 $7,000,000,000 $6,000,000,000 $5,000,000,000 $4,000,000,000 $3,000,000,000 Multi-Megapixel Cameras Standard Def. Cameras IP Camera Market $2,000,000,000 Analog Camera $1,000,000,000 Market $ Manufacturer Value (Arecont Vision Estimates 5.12) Megapixel Means Bigger Images Standard Definition Megapixel 2

3 How Big is It? Resolution Megapixels JPEG High Compression JPEG Low Compression H.264 High Compression H.264 Low Compression CIF 352x k 180k 88Kbps 115Kbps VGA 640x k 420k 272Kbps 353Kbps 720p 1280x k 1024k 350Kbps 1.6Mbps 1080p 1920x k 2175k 490Kbps 2.3Mbps 3mp 2048x k 3210k 740Kbps 3.6Mbps 5mp 2592x k 4685k 1.1Mbps 5.5Mbps 10mp 3648x k 9290k 3Mbps 14.5Mbps Note: there are many variables that will effect bitrate. For the purpose of comparison, this is based on 5 frames per second (fps) frame rate, low activity, 500lux average scene illumination. All resolutions were sampled with the same 10MP camera by image cropping. 10MP 5MP 1080p 720p VGA Coverage Map Drawn to Scale Resolution Benefit: Faces 100 PPF 330 PPM 80 PPF 260 PPM 60 PPF 195 PPM 40 PPF 130 PPM 20 PPF 65 PPM 10MP Camera, 90 lens 36 ft 11.1 m 46 ft 13.9 m 61 ft 18.5 m 91 ft 27.8 m 182 ft 55.6 m 5MP Camera, 90 lens 26 ft 7.9 m 32 ft 9.9 m 43 ft 13.2 m 65 ft 19.8 m 130 ft 39.5 m 1080p Camera, 90 lens 19 ft 5.9 m 24 ft 7.3 m 32 ft 9.8 m 48 ft 14.6 m 96 ft 29.3 m 720p Camera, 90 lens 13 ft 3.9 m 16 ft 4.9 m 21 ft 6.5 m 32 ft 9.8 m 64 ft 19.5 m VGA Camera, 90 lens 6 ft 2.0 m 8 ft 2.4 m 11 ft 3.3 m 16 ft 4.9 m 32 ft 9.8 m Distances from Camera with 90 Lens 3

4 Coverage Map Drawn to Scale 10MP 5MP 1080p 720p Resolution Benefit: Plates 100 PPF 330 PPM 80 PPF 260 PPM 60 PPF 195 PPM 40 PPF 130 PPM 20 PPF 65 PPM VGA 10MP Camera, 90 lens 36 ft 11.1 m 46 ft 13.9 m 61 ft 18.5 m 91 ft 27.8 m 182 ft 55.6 m 5MP Camera, 90 lens 26 ft 7.9 m 32 ft 9.9 m 43 ft 13.2 m 65 ft 19.8 m 130 ft 39.5 m 1080p Camera, 90 lens 19 ft 5.9 m 24 ft 7.3 m 32 ft 9.8 m 48 ft 14.6 m 96 ft 29.3 m 720p Camera, 90 lens 13 ft 3.9 m 16 ft 4.9 m 21 ft 6.5 m 32 ft 9.8 m 64 ft 19.5 m VGA Camera, 90 lens 6 ft 2.0 m 8 ft 2.4 m 11 ft 3.3 m 16 ft 4.9 m 32 ft 9.8 m Distances from Camera with 90 Lens 3 Basic Elements of a Video Network Camera and Power Server, Clients, and Storage Network and Infrastructure 4

5 What Happens in the Camera Megapixel IP Camera Concepts Bitrate Control and Image Compression Bitratecontrol is a method of maintaining consistent bitrates for MPEG compression It can help control bandwidth usage but often at the cost of reducing video quality Works by compressing images as bitrates increase, and reducing fps to maintain limits 5

6 Types of Bitrate Control 2 approaches to bitrate control Variable bitrate (VBR) Constant bitrate (CBR) Variable Bitrate(VBR) Allows higher bitrate for more active video scene while less space is allocated for more static video segments This yields lower average bitratebut allows bitrate variation when scene content has high amount of change Problems can occur if bitrate exceeds the throughput of the network carrying it 6

7 Constant Bitrate(CBR) Maintains a constant bitrate value that can be pre-configured As scene activity increases so does image compression maintain bitrate below defined limit High activity = higher compression which results in lower image quality when it counts the most Compression Reference Low Compression High Compression 14 7

8 Compression Basics Large blocks of like color and texture are combined to a common numeric value Removal of redundant information results in smaller images and less fine detail Compression Basics Areas of the image are analyzed and rendered as single color and brightness values 8

9 Compression Basics Original image was 310kb, compressed now its only 25kb Both images are 1041x1097 pixels See effect in the large blocks of color? Fine detail in the image is lost in the process Understanding Video Compression The two main types of compression technology used for surveillance video: Temporal Compression H.264 (MPEG-4 Part 10) Frame-by-Frame MJPEG 9

10 Temporal Compression I-frames are the least compressible but don't require other video frames to decode B-& P-frames use data from previous frames to decompress and are smaller than I-frames I-frame B-frame P-frame I-frame MPEG Considerations To reliably decode and reproduce a video segment, the entire GOP needs to be received If packets for any one I-, B-, or P-frame are lost or delayed, the entire GOP segment is affected 10

11 H.264 Profiles for Megapixel Profile Type Typical Applications Video Quality Bandwidth High 4:4:4 Predictive Profile High Quality broadcast applications that demand lossless video Highest High High Profile (HiP) Hi Definition and Megapixel applications (Blu-ray uses HiP) Medium Medium Extended Profile (XP) Applications that require high compression and reliability Medium Medium Main Profile (MP) Mainstream consumer broadcast and storage applications Medium Low Baseline Profile (BP) Applications that require additional error checking Lowest Low MPEG standard is managed by the Video Coding Experts Group (VCEG) Information about MPEG standards can be found online at the Moving Picture Experts group website, H.265 standard is a collaboration between the VCEG and ISO/IECMoving Picture Experts Group MJPEG Used for surveillance since the industry began using digital imaging and storage If a frame is lost or corrupted, video segment loses the frame but remains intact (other frames are not affected) Requires more storage and bandwidth than MPEG for equivalent video quality 11

12 MJPEG Continued Simple and mature standard, plug and play Tolerates rapid motion change in video (MPEG can have quality loss with rapid scene changes) More bits to deliver equivalent quality vs. MPEG MJPEG standard is managed by thejoint Photographic Experts Group Information about MJPEG and JPEG2000 standards can be found online at the JPEG committee website, MJPEG & H.264 Image Compression Differences MPEG: More efficient transport and storage More commonly implemented for megapixel IP solutions Sensitive to congested and lossy network conditions MJPEG: Reliable and commonly integrated Every frame captures the entire scene Uses more bandwidth and storage than MPEG 12

13 A Word about Bandwidth Compared to standard resolution video, megapixel bitrates are proportionally larger H.264 offers better average bitrates than JPEG but bitrates are variable and can be subject to spiking in low light or when monitoring high activity Planning sufficient overall bandwidth into the project infrastructure is critical for the success of your project Wire Management Matters! 13

14 Network Speed With more traffic headed to the same destination the potential for congestion becomes greater Plan throughput for maximum load + overhead Consider the traffic destination and potential bottlenecks Planning Large Megapixel Projects Large megapixel surveillance projects can involve hundreds of megapixel cameras on a single campus or distributed across several locations The size and complexity of these projects requires attention in planning and implementation to be successful 14

15 Keeping the Flow Flowing Common Mistakes 15

16 Common Mistakes Scaling it Up 16

17 Managed vs. Unmanaged Switches Unmanaged Passes data between ports as quickly as possible Bandwidth is controlled at the network port Equal priority for all data ports Suitable for a majority of small to medium megapixel installs Managed Managed switches allow control of each port or group of ports Ports can be turned on or off which allows a user to remote hard reboot the camera Ports can be assigned to a VLAN so multiple networks can exist on a single switch Ideal for large enterprise class systems that need a great deal of control over their network environment Layer 2 vs. Layer 3 Both Layer 2 and Layer 3 switches can be used in megapixel IP video networks The choice between them will be determined by the size and needs of the project Simple deployments with less then 200 cameras can use Layer 2 for low cost and simplicity Large networks requiring multiple VLANs require Layer 3 switches (possibly in combination with Layer 2 switches) VLAN 1 VLAN 2 VLAN 3 17

18 Balancing the Load Network Traffic Peak performance 50% Collisions +50% Packet loss +80% Design your video network at 50% H.264 offers reduction in average bitrate but is subject to fluctuation with high activity Planning overhead into the design can accommodate occasional spikes in bandwidth usage Common IP Video Transfer Protocols Thetransport protocolestablishes communication between the camera and VMS It is responsible for delivering video data across the network to the video management software The 2 most commonly used transport protocols used in video networks are TCP & UDP Transmission Control Protocol(TCP) User Datagram Protocol(UDP) 18

19 TCP When problems happen because of network congestion, or other unpredictable behavior, packets can belost, duplicated, or delivered out of order TCP detects problems, requests retransmission of lost data, rearranges out-of-order data UDP UDP uses a simple transmission model with a minimum of protocol exchange There is no guarantee of delivery, ordering or duplicate packet protection VMS applications use UDP because loosing vs. waiting for packets may be preferable in a real time system 19

20 TCP and UDP for Streaming Video RTP over TCP for H.264 Positive: Great for use on busy and enterprise networks (Reliable) Limitation: Multicasting is not supported RTP over UDP Multicasting, quick transport for real time applications Limitation: Not recommended on slow or busy networks Video Management Software Video Management Software can be classified into four categories: Digital Video Recorder Hybrid DVR Hybrid NVR Network Video Recorder Pure VMS Software Appliance based Analog cameras Megapixel cameras Encoded analog 20

21 ONVIF & PSIA Integration ONVIF and PSIA are security industry initiatives that promote plug-and-play interoperability with all certified components Positive: Easy and standardized integration Limitation: They do not include operation of some proprietary vendor features Compression: H.264 & JPEG Documentation on these standards can be found at and Test and Confirm Confirm cameras selected are integrated in the VMS platform chosen for the project and all components play well together Testing and pre-addressing cameras, switches and server hardware before bringing them onsite saves time and eliminates surprises Make sure all cables and connections are certified before plugging in and powering on 21

22 Common Megapixel System Design Challenges Insufficient bandwidth Power and switch setting issues Integration challenges Communication between install and IT team Unrealistic end user expectations Takeaway You can implement megapixel in enterprisesize surveillance systems Success requires understanding the technology, leveraging its benefits, and appropriate system design 22