1. Uncompressed HD Media Transport System: Progress from GLORIAD-KR
JongChurl
JongWon
Jinyong

2. Outline Overview (GLORIAD-KR system) Research efforts Future works
Multiple streams (bi-directional)
OpenGL(SDL)
Sender-view
Networked tiled display
Future works

3. Overview Ultragrid (USC/ISI) extension
XENA HS (AJA Video systems) – Rx & Tx
1920x1080i (25,50,29.97,59.94,30,60 fps)
6-channel audio (24-bit/48KHz)
Video out
XENA HS, SDL, xVideo
Audio out
XENA HS, ALSA
Platform
Redhat 9, Mandrake 10.1, and Fedora Core 5
Open-source :

4. Hardware Sony HVR-Z1N HD display HD-SDI converter
6-channel audio
Audio embedder
A/V transport over IP networks
HD-SDI signal converter
HD display
Speakers
HD-SDI interface
Audio D/A
Audio A/D

5. Software

6. Demo. iGrid 2005, Stereoscopic & uncompressed HD video conferencing
DancingQ 2006, Real-time commercial culture event, “I don’t know”
ELSA 2006, Laparoscopic liver surgery
SC 2006, Software-based A/V playout
Others (2006~)
Experience sharing & real-time experiments with CNIC, TsingHua Univ., EVL, and so forth.
CNIC(Computer Network Information Center) in China  

7. Collaborators

8. Research Efforts Multiple stream (bi-directional) support
Handle incoming/outgoing streams with one machine  Reducing implementation cost.
Downing CPU load is a KEY point
OpenGL(SDL) & sender-view
Smooth display and user facilities
Networked tiled display
Increased sense of presence

9. A Scenario over our Efforts

10. Downing CPU load
Bottleneck tracing & Code-level analysis (with vtune performance analyzer)
Source-code optimization to ream the bottleneck

11. Downing CPU load (for example)
Result of tv_diff() optimization
File name
Function name
CPU load
decoder.c
decode_frame()
18.87%
main.c
main()
11.30%
tv.c
tv_diff()
8.52%
rtp.c
rtp_recv_data()
7.02%
pbuf.c
pbuf_decode()
4.42%
File name
Function name
CPU load
decoder.c
decode_frame()
19.65%
main.c
main()
13.57%
rtp.c
rtp_recv_data()
7.63%
rtp_callback.c
rtp_recv_callback()
4.20%
tv.c
tv_diff()
3.81%

12. Multiple stream support
Apply port-based stream selection
Share one IP address - Use different ports
10 Gbps interface
Use different IP addr.
Two 1 Gbps interface

13. OpenGL (SDL) & Sender View
Add SDL module
Sender View module (Sender-side view)
Init library
display
index change
Finalize
Display Module
loop
OpenGL API
Main
HD display
Receiver
Main
Frame grab
Transport
1. Store captured frame
2. Make pipe to forward frame for sender’s view display
3. Display video on sender’s screen
Forward Frame
OpenGL API
HD display

14. Multiple stream support & Sender-side view
Receiver view
Receiver view
Sender view
Sender view

15. Networked Tiled Display
To link video out to tiled display
Convert YUV to RGB
Frame delay

16. Tiled Display – Performance Issue
Problem: Permits only one frame and is forwarded at one time.
They causes frames delay
Solution: Insert condition at critical section
While one packet is being transmitted, the subsequent packet is thrown by conditional without waiting.

17. Tiled Display
Increased Quality

18. Future Works Keep optimizing software bottleneck
Support multiple XENA HS interfaces
Full rate playout over tiled display
Protocol bridging (TCP and UDP)
Uncompressed HDTV and Tiled display

19. Thank you! Contact jcpark@nm.gist.ac.kr http://www.gloriad-kr.org/hdtv