1. HD video in teaching environment
Eva Hladká, Ludek Matyska
CESNET, Prague, and
Masaryk University, Brno
Czech Republic

2. Overview Two Collaborative Concepts Virtual Classroom Concept
Collaborative Technologies
HD Video
Introduction to HPC class
Participating institutions
Network setup
Site Setup
Time-Shift Problem and its Mitigation
Lessons Learned
San Diego, October 9th 2007 I2

3. Two Collaborative Concepts
“In” and “Out”
“In” – collaborate in a virtual world (on line games, Second Life etc.)
System (virtual world) explicit and important part
“Out” – bridge the physical distance (classical videoconferences)
Invisible system
San Diego, October 9th 2007 I2

4. The Learning Process The teacher as the focal point
Verbal expression
Non-verbal expression
Empathy, …
We should not “hide” the teacher
Virtual classroom – implementation of the “Out” concept
San Diego, October 9th 2007 I2

5. Virtual Classroom Concept
“In” concept: strictly digital classroom, avatars
“Out” concept: several physical classrooms sharing one teacher
The problem:
To make teacher’s presence as natural as possible in all “instances”
Use of advanced collaborative technologies
San Diego, October 9th 2007 I2

6. Collaborative Environment
High Definition (HD) Video
High picture quality
Able to record and display classical screen without any distortion
Both a screen/blackboard and a teacher as seen in a single classroom
Huge amount of data, difficult to process (compress/decompress) in real time
Use of uncompressed video
Accompanied with uncompressed audio
San Diego, October 9th 2007 I2

7. HD Video Formats
San Diego, October 9th 2007 I2

8. HD Video Parameters Used
Basic parameters
Effective resolution 1920x1080 pixels
60 interlaced fields per second
4:2:2 color space sampling with 10b per color plane
Packetizing
8500 B Jumbo Ethernet frames
Data rate of 1.5 Gbps one stream
Processing: UltraGrid software
San Diego, October 9th 2007 I2

9. Actual Class Taught Introduction to High Performance Computing
Prof. Thomas Sterling, LSU, LA, USA
Five participating institutions
Masaryk University, Czech Republic (Europe)
University of Arkansas
Louisiana Technical University
MCNC, North Carolina
North Carolina State University
Spring semester 2007 (January till June)
San Diego, October 9th 2007 I2

10. Data Distribution
San Diego, October 9th 2007 I2

11. Data Distribution II Based on a set of packet reflectors
Located in appropriate places in the network
Create a logical overlay network
Used instead of Multicast (higher reliability)
Minimizing the data actually transmitted over any physical link
1:N and N:1 video distribution
Only teach sees everybody
N:N audio distribution
San Diego, October 9th 2007 I2

12. Data Distribution III
San Diego, October 9th 2007 I2

13. Site Setup
HD camera
Plus processing hardware/software
Only LSU (Johnston) needed several projection screens
LCD/Plasma or full HD projectors
Stream capture (MU)
RAID0 disk array (needs >200MB/s)
1TB per 1.5hour lecture
San Diego, October 9th 2007 I2

14. Audio Using RAT from MBone Tools Uncompressed stream
16 b quantization, 48 kHz sampling rate
Data rate 1.6 Mbps
N:N distribution
Most important—the microphone quality
Changes several times during the semester
Bad audio could cancel the lecture
San Diego, October 9th 2007 I2

15. LSU Setup
San Diego, October 9th 2007 I2

16. MU Web Pages (Materials)
San Diego, October 9th 2007 I2

17. MU Web Pages (Videos)
San Diego, October 9th 2007 I2

18. Problems Time-shift problem
Different time zones
Different beginnings of a semester
Actual interaction among different students’ groups
Problem sets and homework
Similar environment is necessary
Computing cluster, high performance network, batch system, compilers, …
San Diego, October 9th 2007 I2

19. Time Shift Mitigation Different time zones
Negotiations
Did not work for this case
LSU started at 3pm  MU at 10pm
With truly global collaboration always somebody “out of usual working hours”
Different start of a semester
Those starting later must catch the delay
Necessity—access to stored lectures
San Diego, October 9th 2007 I2

20. Time Shift Mitigation II
MU started to capture HD video stream when the lectures at LSU started
TA time intensive, twice a week, 10pm till midnight
Students agreed to watch more than two lectures per week
However, problem with homework
Hints in “future” lectures
Lesser time available (overlap of problem sets)
Actual lectures started at 7pm
When delay removed, students invited to stay for the real time lectures
San Diego, October 9th 2007 I2

21. Lessons Learned Lot of manual work Setting/tearing networks
Both recording time and the re-play
Setting local environment and adapting problem sets to it
Sharing the evaluation process (points)
San Diego, October 9th 2007 I2

22. Lessons Learned II Adaptation to problems
Not so hot for recorded lectures
Real time adaptation very difficult
We run a back up solution using AccessGrid and Webcasting in Quick Time format
Need to develop more detailed monitoring of the network and automatic reaction to any problems (including change of the collaborative environment)
See CoUniverse information sheet
San Diego, October 9th 2007 I2

23. Lessons Learned III Students and teacher interaction
Must be directly incorporated in the materials
Interactive feedback required
Some mitigation for delayed groups
Problem sets to be solved by group of students (from different institutions)
General enough not to be thwarted by the time shift (esp. different start of semester)
San Diego, October 9th 2007 I2

24. Conclusion
The Introduction to HPC class ran during the Spring semester 2007
Using collaborative environment based on uncompressed HD video and audio
At 5 institutions, almost 100 students attended and passed the class
Including all the homework, projects, …
We plan to repeat the experience next Spring for some 15 institutions round the globe
San Diego, October 9th 2007 I2

25. Thank you for your attention
Questions?
San Diego, October 9th 2007 I2