1. Video Conferencing : Fundamentals and Application Prof. J Mukhopadhyay Dept. of Computer Science and Engineering, IIT Kharagpur

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

5. MODES OF VIDEO CONFERENCING Point-to-Point A videoconference that connects two locations Multi-point A videoconference that connects more than two locations through a Multi- point Control Unit ( MCU )

16. Band-width requirements of different compressed multimedia data 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 medical images 6 Mbps~120 Mbps HDTV 110 Mbps~800 Mbps Scientific Visualisation 200 Mbps~1000Mbps

18. MPEG Introduction For each 8x8 block DCT Quant . RLE { Zig-Zag Scan Huffman …… 011000011010 Intra Frame Encoding

19. Motion Estimation & Prediction to construct Inter Frame (P/B- frames) Reference m’ e = m – m’ MPEG Introduction Back 1 2 3 4 5 6 7 8 9 10 11 m 13 14 15 16 17 18 19 20 21 22 23 24 25 Predicted P

20. MPEG Introduction P-Frame Encoding B-Frame Encoding Back Reference Best Match Motion Vector } Difference DCT + Quant. + RLE Huffman 01101100 Past reference Future reference Target [ + ] = - 0.5 x DCT + Quant. + RLE Huffman coder 01101100 Motion vectors

21. MPEG Introduction INTRA INTRA Motion Compensated Inter Frames Encoding Decoding Details (DCT, Quant., Motion Estimation & Compensation, VLC) (IDCT, IQuant., Inverse Motion Compensation, VLC)

22. A Typical MPEG stream Structure Seq. Header GOP Header GOP GOP Header GOP MPEG End Code ----------------------- Pic. Header PIC ----------------------- MacroBlock header Macroblock Block 8x8 Block 8x8 Block 8x8 I B B P B B P B B P B B I B B . . . I P P P P P P P P P P P I P P . . . I I I I I I …. MPEG Introduction ----------------------- -----------------------

30. NETWORK CHOICES ISDN - Connects sites utilizing the H.320 standard IP - Connects sites utilizing the H.323 standard The most cost effective speed for typical videoconferencing meetings is 384 Kbps or 512 Kbps.

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

36. A typical VC Class Room LCD Projector & Laptop Interactive whiteboard LCD TV 42” with panel speakers Standard PTZ camera Streaming/Archiving Device PRI ISDN Brick Multipoint software (for ISDN) Multipoint software (for IP) Data solution box (transfer screen shots) External (tabletop microphones) Video conferencing unit (Codec Unit) Components

37. A TYPICAL BOARD ROOM SET-UP External (tabletop microphones) LCD TV 42” with panel speakers Video conferencing Unit (Codec Unit) Components

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

56. Over-all View Client’s GUI Stream-1 Stream-2 Stream-3 Streaming-OBJ-2 Streaming-OBJ-2 Stream-n Connection Object OpenLDAP Authentication Authenticated Access Render Stream Acquired Video Streaming-OBJ-1 Fetch Remote Stream & View Acquire Video

57. eBaithak – Local Video Local Audio Video Allow Transmission Modes Video Quality Control (FPS,RES,QLT)

58. eBaithak – Remote Video Local Audio Video Allow Transmission Modes Video Quality Control (FPS,RES,QLT) Connected Users Connected Users ZOOM: Magnifies Video Aud:ON/OFF: Controls Incoming Audio

59. Thank you