1. Challenging 5 Common Assumptions about Videoconferencing Milton Chen Computer Systems Lab Stanford University Presented at Internet2 Advanced Applications Track 10/28/2002

2. The Stanford Video Auditorium desktop interface 15’ x 5’ video wall

5. 1. High-fidelity low-latency AV requires dedicated hardware

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

8. demo

9. A scalable AV streaming architecture * TrueSpeech 8.5 * MPEG-4 * Encrypted, AES (Rijndael), streaming * Simultaneous AV recording * Perceptual streaming adapts to network conditions audio capture audio compress audio send audio receive audio decompress audio render video capture video compress video send video receive video decompress video render

11. 2. Videoconferencing systems are difficult to install and use

13. 3. Life size displays are ideal

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 °

16. 4. Effective floor control requires interactive frame rate

18. Gesture Detection Algorithm input image frame difference after erosion Visualization of algorithm

19. Requires 10% of full motion bandwidth full-motion (10 fps) gesture-sensitive (0.2 fps) * MPEG4 encoded at 320x240

20. Gesture sensitive allows dynamic discussion 15 fps ~0.2 fps 0.2 fps * 8 groups of 4 people during a discussion

21. 5. Eye contact is difficult

22. Eye contact fires up our brain [Kampe et al. ’01]

23. Eye contact is difficult Looking into the camera Attempting eye contact

24. Solutions to eye contact Half-silvered mirror [Rosenthal ’47] MAJIC [Okada, et al. ’94] ClearBoard [Ishii, et al. ’92] GazeMaster [Gemmell, et al. ’00]

25. A simple solution Hydra [Sellen, Buxton, and Arnott ’92]

29. Sensitivity is asymmetric * 16 observers judged recorded videos of 1 looker

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

35. Eye contact in the Video Auditorium

36. Why is videoconferencing essential to distance learning: An evaluation of distance learning at Stanford

38. Students like distance learning * 120 students, 15 TAs, and 41 faculty

39. Learning is less effective * 120 students, 15 TAs, and 41 faculty

40. F2F interaction is important F2F is important for lecturing and crucial for discussions

43. A proposal

45. A prediction

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

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