Video Conferencing : Essentials and Application Prof. J Mukhopadhyay Dept. of Software engineering and Building, IIT Kha.


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By and large, feature conferencing is the following best thing to an eye to eye ... EBaithak: Multiparty Desktop Video Conferencing over Internet ...
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Video Conferencing : Fundamentals and Application Prof. J Mukhopadhyay Dept. of Computer Science and Engineering, IIT Kharagpur

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VIDEOCONFERENCING THE POWER OF VISUAL COMMUNICATION To See, Hear and Share Information utilizing Video and Audio Technology

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Modes of Interactions Email. Fax. Phone. Online Chat. Video Conferencing. Up close and personal. Much of the time, video conferencing is the following best thing to an eye to eye meeting.

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Why Video Conferencing? Spare cash and time. Construct connections. Impart "eye to eye" where it would some way or another be inconceivable. Stay away from ventures. Educate. Work together.

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MODES OF VIDEO CONFERENCING Point-to-Point A videoconference that interfaces two areas Multi-point A videoconference that associates more than two areas through a Multi-point Control Unit ( MCU )

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COMPONENTS OF A VIDEOCONFERENCING Camera Codec intuitive whiteboards Display Devices Streaming & Archiving Equipment Microphone

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Technologies Involved Video and Audio signal securing. Information Communication. Presentation and propagation of transmitted sign.

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CAMERAS TYPICAL FEATURES AT A GLANCE : High Speed, Wide Range Pan/Tilt & Zoom 40x Optical Zoom, High Speed and Auto-Focus Lens S-Video & Standard Composite Output 12 or more Position Preset Auto Tracking/Motion Detector RS-232 Serial Control Via Your Computer Through The Internet IR Hand Held Remote Control 9600 Baud Data Pass-Through Mode Time/Date Generator

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MICROPHONES OMNI DIRECTIONAL UNIDIRECTIONAL An Omni Directional Microphone which grabs sound similarly well from all bearings. It has 360 degrees of voice get and an Integrated Mute catch A Unidirectional amplifier is touchy to sounds from one and only course.

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Typical elements of a LCD TV Viewing edge :  176º (H)/176º (V) Diagonal screen size (inch) :  42 inch Display screen sort :  LCD WXGA Active Matrix TFT Panel determination :  1366 x 768p Sound Output power (RMS) :  2x12W + 1x24 W Loudspeakers Built-in speakers :  5 Loudspeaker sorts :  Integrated subwoofer, Dome tweeter Picture in Picture :  HDMI-Component PIP Playback Formats :  MP3, Slideshow records (.alb), JPEG, Still pictures Mains power :  AC 110 - 240 V +/ - 10% Power utilization :  263 W

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Bandwidth/Data Rate Requirement Frame Rate. Outline Size. Shading. Mono/Stereo Audio. Test every second. Bit per test. 15-30 fps. QCIF( 176x144) , 4CIF (480x330) and so forth 14 KHZ Audio 8-12 bit for sound, 24 bit for video

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Data Size: Voice Band width: ~ 4 Khz Minimum Sampling Frequency: 8 Khz Bits for every specimen: 8 bits (for 256 levels) Minmum information rate: 8000x8 bits for every second = 64 Kbps

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Data Size: Video Number of edges every second: 15 fps Resolution of an edge: 480 x 640 pixels Bits for each pixel: 24 bits (for shaded video) Data Rate: 480x640x15x24 bits for each second = 110.6 Mbps

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Compression Standards Lossy and Lossless Compression Audio: G.711, G.722.1, G.728, MPEG-4 Still Image: JPEG, JPEG-LS, JPEG-2000 Video: MPEG-2, MPEG-4, H.263, H.264

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Type of Multimedia Data Bandwidth Usual data 100bps~2kbps Image 40 Kbps~150 Kbps Voice 4 Kbps~80 Kbps Stereo Audio 125 Kbps~700 Kbps VCR quality video 1.5 Mbps~4Mbps 3D therapeutic images 6 Mbps~120 Mbps HDTV 110 Mbps~800 Mbps Scientific Visualisation 200 Mbps~1000Mbps Band-width prerequisites of various compacted mixed media information

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Protocols for VC H.320 ( 1990) ISDN H.323 (1996) IP SIP (Session Initiation Protocol) Used by most Voice Over IP ( VOIP ) arrangements

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H.323 contains a few conventions: H.225.0 : Call Signaling between two H.323 endpoints Registration, Admission, and Status (RAS) . RAS is utilized between an endpoint and a Gatekeeper. H.245 :control convention for opening and shutting intelligent channels for sound, video and information, capacity trade, control and signs. H.450 : for different supplementary administrations

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H.323 (Contd.) H.235 : for security inside H.323, including both flagging and media security H.239 : depicts double stream use (normally for live video, the other for presentation.) H.460 : discretionary augmentations that may be actualized by an endpoint or a Gatekeeper. Notwithstanding those ITU proposals, H.323 uses different IETF RFCs for media transport and media packetization, including RTP .

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H.323 (Contd.) Codecs Video codecs: H.261 , H.263 , H.264 . Sound codecs: G.711 , G.729 , G.729a , G.723.1 , G.726 Text codecs: T.140

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OPTIONAL ACCESSORIES Data Solution Box Streaming/Archiving Equipment Interactive Whiteboard LCD Projector & Laptop Interactive Whiteboard : Using an Interactive whiteboard recorder, notes and drawings on a whiteboard can be electronically changed over and afterward moved continuously to remote destinations to be shown on a screen. LCD Projector & Laptop : A projector utilizing LCD innovation and s shopping center compact PC. Information Solutions Box: Transfer screen shots in XGA determination from your PC to remote destinations through a system or an ISDN line. Gushing/Archiving : A gear for spilling/documenting the addresses/interviews/classes and so on

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Challenges in Internet VC Firewalls Port Blocking NAT Hidden IP Address Bandwidth NOT! Dial Up Modem MAYBE… Cable Modem/DSL Yes!!! Internet2

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Network Servers for VC Gatekeeper Allows task of static numbers Allows utilization of MCUs, and Gateways MCU Allows more than two members to be in the call in the meantime. Passage Allows calls to and from phones. Ridgeway Server Firewall/NAT arrangement.

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MCU GateKeeper H.323 Real Video Web Browser H.323 Videoconferencing H.320 Telephone ISDN POTS line Gateway INTERNET H.323 Clients

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A run of the mill VC Class Room

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A TYPICAL BOARD ROOM SET-UP

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EBaithak: Multiparty Desktop Video Conferencing over Internet Developed at Dept. of CSE, IIT, Kharagpur

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Video Servers Progressive Video records are kept at an area on the server. Records can be downloaded at a later stage for survey in an appropriate player The issue is entire documents must be downloaded before really playing Any Server can have multi-media records. Gushing Video records are kept at an area on the server. Video record is played as it is being downloaded. Video record need not to be spared at the customer Special gushing servers to be utilized for facilitating documents RED5, WOWZA, FMS, DARWIN, MICROSOFT MEDIA SERVER are illustration.

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Protocols Used RTMP Available as an open particular to make items and innovation that empower conveyance of video, sound, and information in the open AMF, SWF, FLV, and F4V groups perfect with Adobe Flash Player RTMPT Basically is a HTTP wrapper around the RTMP convention Send POST asks for from the customer to the server. Customers to survey for upgrades occasionally so as to get told about produced occasions Four conceivable solicitation sorts can be sent to the server Initial interface (order "open") Client redesigns (charge "send") Polling asks for (summon "idle") Disconnect of a session (order "close") RTMPS works simply like RTMPT, however over a safe HTTPS association

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eBaithak – Server Part eBaithak utilizes Red5 as its Media Server Red5 is Open Source Flash Media Server written in Java Protocols Supported: RTMP/RTMPT/RTMPS RTMP : Real Time Messaging Protocol is a restrictive convention of ADOBE Systems. RTMP in light of top of TCP and utilizations 1935 port RTMPT is RTMP typified inside HTTP asks. RTPMS is RTMP typified with in secure HTTP asks for

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eBaithak - Client Flash Application Flash is a mixed media illustrations program uncommonly for use on the Web Flash empowers you to make intuitive Applications on the Web Flash uses vector design, which can be scaled to any size without losing clarity/quality ActionScript v3.0 is utilized for programming convoluted Flash Applications

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eBaithak & Flash Software Client Side : Adobe CS4 for creating GUI Uses Action Scripting 3.0 Adobe Flash Player for showing GUI Across-stage program module that conveys sight and sound substance. Implanted inside html pages which can be served through Red5 Server.

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eBaithak & Flash Software Server Side : Embed Flash Application inside server-side scripting program like JSP/ASP for Client Access: <object width="550" height="400"> <param name="movie" value="somefilename.swf"> <embed src="somefilename.swf" width="550" height="400"> </embed> </object> This can be spared a HTML document and must be put on the site alongwith "somefilename.swf" Flash application

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Client Requirements Installed Webcam, Head-Phones Any web-program with blaze player introduced. Web association for interfacing Video Server User certifications for interfacing the server.

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Red5 Application (Server Side) In Simple structure, it is a server side java program, facilitated on the Red5 Server. It contains techniques, for example, interface, appConnect, begin, stop and so on. Confirmation and so on are connected in appConnect strategy If any VOD information is there, it can be facilitated in the streams index.

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Video Quality Parameters Quality of Video Depends on the accompanying components:- Frame Rate : This parameters characterize what number of edges are shown in one second. Outline Resolution : Dimensions of every edge. Outline Quality : Compression of every edge. Bitrate : Supported on particular Video Formats Quality of pictures in the video rely on upon Frame Resolution & Quality. Smoothness of Vid

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