1. Challenging 5 Common Assumptions about Videoconferencing Milton Chen Computer Systems Lab Stanford University Presented at Internet2 Advanced Applications Track 10/28/2002
6. Your PC outperforms all dedicated systems $700 Pentium 4 computer $7000 systems outperforms
7. Comparison of videoconferencing solutions * CUSeeME, iVisit, Yahoo messenger have unacceptable latency 400 Kbps 720x480 many AccessGrid, VRVS 3000 Kbps 720x480 1 WIDE DVTS 200 Kbps 352x288 4 Polycom, Sony, … 16 to more than 100 1 1 Max number of links 2000 Kbps 720x480 Vbrick 100 Kbps 720x480 Stanford Video Auditorium 200 Kbps 352x288 NetMeeting BW required at 352x288 15fps Max video resolution
15. Balance between size and head movements * 12 people viewed 9 and 36 students on a large and immersive display. Immersive display requires head movements to see all the students. 9 ° 14 ° 7 ° 4 °
30. An anatomical explanation looking at you looking sideways looking up looking down eye closing Illustrations from The Artist’s Guide to Facial Expression [Faigin ’90]
31. Sensitivity is less in conversation * 16 observers judged videos of 1 looker (down) recorded conversation
32. Sensitivity is less in video * 16 observers judged 1 looker in conversation (down) face-to-face video
33. We are biased to perceive contact angle eye contact (%) sideway, up down down & video down & video & conversation Snellen Acuity Conferencing Acuity 0 100
34. Maximum camera to eyes distance * Assuming a sensitivity of 7 ° 12” 8’ Wall size 3” 2’ Desktop 1.5” 1’ Palm held camera to rendered eyes distance minimum viewing distance device
47. Threshold of quality for the 2nd revolution first mobile phone, 1924 first handheld phone, 1973 1 st Revolution: Possible 2 nd Revolution: Practical first videoconferencing system, 1927
48.
49. You already have a one-click high-fidelity multiparty videoconferencing system We are at the dawn of a videoconferencing revolution that will fuel the demand for a 1000X increase in available bandwidth