1. 2003. 8. 28 Tae-wan You, Seoul National University, Korea
Design and implementation of IPv6 multicast based High-quality Videoconference Tool (HVCT)
Tae-wan You,
Seoul National University, Korea

2. Outline HVCT and Features Software design Implementation Details
Experimental result
Future work

3. HVCT & Feature

4. HVCT a High-quality Video Conferencing Tool
Works on Windows 2000, SP 1 with IPv6 stack
Microsoft DirectX 8.0 or Higher
Video data be en/decoded using MPEG-4 Codec
Video : 320x240 pixels, 15fps
Audio data be en/decoded using MP3 Codec
Audio : 44kHz, 16bit, 2 channel

5. Feature (1/2) IPv6 capability Multicast Support
Working on MSR and MSDN IPv6 stack
Multicast
Efficient use of network resources via multicast
Support
High-quality multimedia data using MPEG4 codec and MP3 codec
Show a statistics that be measured traffic
Can chat using multicast

6. Feature (2/2) Main dialog of HVCT Traffic monitoring
Show screen of
participants
Traffic monitoring
total number of
bytes received
packets lost
packets misordered
represent a bandwidth
using graph
Chat with participants
by multicast protocol

7. Software Design

8. Software Components Encoding Manager Decoding Manager Network Manager
MPEG4 Video
Software Encoder
MP3 Audio
MPEG4 Video
Software Decoder
MP3 Audio
A/V
MUX
RTP over
UDP/IPv6
Network Manager
A/V
DEMUX
The Encoding Manager
This part is to process the multimedia data acquired from a video camera and a microphone
… transmitted to A/V MUX (Audio and Video Multiplexer).
A/V MUX makes video stream and audio stream into one stream and sends it to network manager.
The Network Manager
This part takes charge of role that sends to or receives from destination multimedia data that receive through A/V MUX using RTP and RTCP protocol
The Decoding Manager
This part is to process multimedia data received through network. A/V DEMUX (Audio and Video De-multiplexer) separates stream received from network manager into video stream and audio stream

9. Software Components Encoding Manager Network Manager Decoding Manager
Make an one stream with video data, which be encoded using MPEG4 codec and audio data, which be encoded using MP3 codec.
Network Manager
Add RTP header with stream and send it as udp packet to multicast address for IPv6
After receive a packet, remove RTP header and pass data to DM (Decoding Manager)
Decoding Manager
decode the each of the stream and play both audio and video using Render filter

10. Software Architecture
User Interface
DirectShow
Filter
(Capture)
DirectShow
Filter
(Display1)
DirectShow
Filter
(Display2)
DirectShow
Filter
(Display3)
RTP/RTCP & Buffer
SocketThread
(for send data)
SocketThread2
(for receive data)
Control Message
Data Stream

11. Implementation Details
Multimedia Data Transfer

12. Sender Component Capture Driver MPEG4 Encoder Video Tee MPEG4 Decoder
Video Renderer
Sound Driver
MP3 Encoder
Audio Tee
MP3 Decoder
Sound Driver
Audio/Video
MUX
Video Stream
RTP/RTCP
Audio Stream
A/V Muxed Stream
UDP/IPv6
IPv6 Multicast Network

13. Receiver Component Video Source MPEG4 Decoder Video Renderer
Audio Source
MP3 Decoder
Sound Driver
Audio/Video
MUX
Video Stream
RTP/RTCP
Audio Stream
A/V Muxed Stream
UDP/IPv6
IPv6 Multicast Network

14. Implementation Details
RTP/RTCP Data Transfer

15. RTP, RTCP Library The library be implemented on the basis of RFC 1889
Define data type by structure in C++
RTP, RTCP, RR, SR, SDES etc.
Made functions that can achieve accomplishments that is supported by RTP, RTCP using defined data types

16. … InitRtp SetRtpSdes SendRtpCtrl SendRtpData OnRecvRtp UpdateRtp
MySSRC …
Create Session
Rtp socket Rtcp socket
InitRtp
SetRtpSdes
Participant db
Create db
SendRtpCtrl
SendRtpData
APAN-SNU
Multicast data/ctrl
KOREN
SEOUL AP
IPv6 Host
IPv6 Router
OnRecvRtp
UpdateRtp
SendRtpBye
done

17. Join Session & Start Talk
Participant 1
ff0e::1:2:3 / 5002
Participant 2
Join Session
RTCP (RR,SDES)
RTCP Interval of Participant1
RTCP (RR,SDES)
RTCP (RR,SDES)
Start
Send Data
RTP (MPEG, MP3 payload)
RTCP (SR,SDES)
Start Playing / Participant 1 := Active Source
RTP (MPEG, MP3 payload)

18. Experimental result & Future work

19. Experiment environment
ATM S/W
ETRI
ATM S/W
Daejeon AP
ATM S/W
Seoul AP
ATM S/W
SNU AP
ATM S/W
PC Router 1
PC Router 2
Host 1
Host 2
Subnet A (ETRI)
Subnet B (SNU)

20. Result – bandwidth Video by MPEG-4 Codec Audio by MP3 Codec
Input data : 15 frame per second, I420 format
Output data : 350 ~ 400Kbps
Audio by MP3 Codec
sample 16bit, two stereo, sampling rate 44.1kHz
16 * * 2 =~ 1.3 Mbps
Output data : 56 kbps

21. Bandwidth compare with vic
UCL’s vic
H.261, 10fps
RGB24 format
HVCT
MPEG4, 15fps
I420 format

22. Result – delay (1/2)
Video Delay

23. Result – delay (2/2)
Audio Delay

24. Future Work Reduce end-to-end delay
Experiments with other conferencing tool
VIC from UCL, ISABEL from Agora Systems etc.
Performance Test
You can get more information from

25. Thank You !! & Any Questions ?