This document provides details of an embedded systems project to develop a video chat application. It includes the names and contact details of the team members, an agenda for the progress presentation, and sections on the product concept and design including the video codec chosen, hardware platform, and work allocation among team members. Key aspects covered are the video and audio processing, network testing conducted, and timeline with tasks scheduled till completion.

1. EMBEDDED SYSTEMS PROJECT
TD6109
Video Chat Application
Progress Presentation
Team 2
Name Matriculation
Number
Contact
Mr. Tan Chiew Seng Sean HT035691L H/P:9848 4822
G0308113@nus.edu.sg
Mr. Ravi Kishore Doddavaram HT035687R H/P:90262765
G0303050@nus.edu.sg
Mr. Sunil Gullipalli HT035690Y H/P:98550495
G0303051@nus.edu.sg
Mr. Santanu Bhattacharya HT035673H H/P:98558727
G0308103@nus.edu.sg
Mr. Gaurav Khurana HT035678N G0308105@nus.edu.sg
20th
August 2004

2. Agenda Today
 Product Concept
 Design Overview & Tradeoffs
 Demonstration
 Timeline & Work Allocation

3. Product Concept:
Embedded IR
Sensor
Rotatable base
Embedded
Camera with Digital
Zoom
Embedded VC
Speakers
VC Addon (VCA)
TV
1. Main Menu Call Duration
2. Save No.
3. End Chat
4. Settings
Out of Range Indicator
(LED)

4. ZONING DIAGRAM
VC Addon (VCA)
Embedded VC
Speakers
Embedded
Camera
With Digital Zoom
Rotatable base
Voice
Control
Interface
(VCI)
IR Zone 1
IR Zone 2
IR Zone 3
IR Zone 4
Voice activated range Command based
6 to 8 m
Out of Range Indicator
(LED)
Living
Room
Sofa
TopViewof
VCA

5. System
(From the Network)
CalleeVideo Callee Audio
Input Input
Caller Video Input
Caller Audio Input
Caller Video Output
Caller Audio Output
Network
Stream
User Input from the
Remote control
Callee Video Output
Callee Audio output
Information Stream
Skeletal Functionality

6. INFORMATION TRANSFORMATION / DATA FLOW DIAGRAM

7. Design Trade-offs
1. Video Codec
2. Platform
3. Processor
4. Audio Codec
5. Video Input Capture
6. Software Platform
7. GUI tools
8. Processor

8. Design Tradeoffs :Video Codec
 Criteria
 Bandwidth
 Compression ratio
 Image quality
 CPU Load
 Options
 H261
 H263
 MPEG

9. Selected: Video Codec
 H.263 Video Codec
 Low bit rate :Suitable for dial-up connections
 High Quality transmission :Suited for TV
conferencing
 Interoperable :Standard for present Video
Conferencing Systems.
 Not H.261 : H.263 is Error tolerant.1/2 pel
Motion estimation.
 Not H.264 : H.263 is the existing standard and
is backward compatible with H.264.

10. Design Tradeoffs : Hardware Platform
 Criteria
 Development time
 Cost
 Learning curve
 Available support
 Size of the board
 Suitability such as boot up time, power consumption etc.
 Options
 A single board Computer (SBC)
 Customized PCB (assorted chips)
 Development boards (TI C6X development platform)

11. Hardware Platform
 Intel Celeron Processor (1.26 GHz)
 64 MB IDE FLASH
 256 MB SDRAM
 PS2 IR Receiver
 Ethernet RJ45
 USB1.1 ports

12. Design Tradeoffs : Audio Codec
 Criteria
 Bandwidth
 Jitter or delay
 Echo effects
 CPU Load (not as significant as Video)
 Options
 G711
 G723
 G729
 GSM

13. Selected: Audio Codec
 Codec G 723
 20 bytes/frame
 Frame rate 30 ms/frame =
33.33 fps
 Note 1 frame = 1 packet
 Latency 30 ms
 Raw bandwidth = ( 24 * 8 ) / ( 30
* 0.001) = 6400 bits per second
 With the RTP 17066 bits per
second

14. Design Tradeoffs : Video Input Capture
 Criteria
 Picture quality (perceived)
 Capture rate hence transient response
 Resolution
 Output formats
 Cost
 Complexity and compatibility
 Extra hardware
 Extra space
 Options
 Analog Camera
 USB Camera

15. Video Input
 Web Camera or analog camera
 Analog Camera
 Better quality
 Compact solution
 Requires an expensive ADC (Image Capture Card)
 S-Video or Composite RCA feed (analog)
 Extra volume of the product
 Web Camera
 Simpler solution
 USB interface hence does not require power
 AVI video input (Digital samples hence easier to process)
Logitech
Quickcam Pro 4000

16. Design Tradeoffs : GUI
 GUI : Qt/Embedded
 Compact Library
 Hardware-accelerated graphics: Suited for
Video Conferencing
 Runtime-Memory conservator
 Easy to build and preview user interfaces
 Not SDL: Size does matter!
 GUI requirements using X11
 - X Windows 5 MB RAM, 16 MB disk
 - GNOME 14 MB RAM, 95 MB disk
 - KDE 11MB RAM, 96 MB disk

17. Design Tradeoffs : IR
 Infra red Capabilities:
LIRC
 Open Source ,Easy to
configure
 Can talk to Qt
 Serial port receiver at
38KHz
 Less deployment time
 Easy to test

18. Design Tradeoffs: Processor
 Options
 Celeron
 Pentium III
 Pentium IV
 VIA
 ARM
 TI C64
 Criteria
 Cost
 Application Load
 Platform
 Software Compatibility

19. MIPS Calculation
Operation Before Optimization
Motion Estimation 11187000
Motion Compensation 216150
DCT 141900
Quantization 63525
Interpolation 139425
Reconstruction 255750
Others 429000
Total
CPU Cycles
/Frame (CIF)
12432750
Data Rates of H.263 Codec:
The Uncompressed bit-rate for 30 frames/sec (CIF) = 352 X 288 X 24 X 30
CIF Pixel Bits/Pixel Frame/Sec
= 73 Mbit/sec
Compression rate of 1:100 to 1:400 is achievable by H.263 Codec
The minimum bit-rate for up-stream = 0.8 Mbits/sec
The minimum bit-rate for down-stream = 0.8 Mbits/sec
So, Total bit-rate requirement = 1.6 Mbits/sec

20. Processor load
 CPU load is very minimal for these drivers
 During the start-up they take up 12-15 % of the
kernel processing time
 DMA takes care of these devices using character
interfaces

21. Processor
 Celeron
 Cheap
 MMX
 SIMD
 Meeting Our Application Requirements

22. Possible Solutions for Audio
 ALSA- 1.0.5 (stable release)
 Compatible and under heavy development for the
2.6 kernel
 Modular support built into 2.6.x kernel
 Provides excellent API for interfacing the audio
with the application
 OSS- 0.9
 Ships with the 2.4.x kernel

23. PROPERTIES OF THE OBJECTS IN THE SOLUTION
 Video Codec – H.263
 Video Input Capture
 Hardware Platform
 Infra-red
 Graphical User Interface (GUI)
 Audio Codec
 Audio Input Capture
 Software Platform
 TV Input

24. Video Processing Considerations
 CIF to 4CIF conversion
 Transmitting a CIF (352X288) video stream and
interpolate it into 4CIF (704X576) at Receiver to
display.
 Using Linear Interpolation up to now considering
the CPU load.
 Trade of between the video quality and CPU load.
 The work for still image interpolation is done.
 The work for a CIF video stream to 4CIF video
stream is going on.

25. Video Processing Considerations
Original CIF Image
(352X256)
Linear Interpolated Image 4CIF (704 X 576)
CIF to 4CIF
Conversion
Results

26. H.263 Video and G.723 Codec Testing Over the
N/W
 Testing Inputs
 Terminal 1 (Listener): @ 172.19.79.106
Video Device : /dev/video0 ( Webcam port)
Video Input : From the webcam
Video Size : QCIF
Video Bit rate : 1024Kbps
Video Transmission quality : 4 ( best possible for net meeting)
FPS : 15
Auto- Answer , No Gatekeeper
 Terminal 2 (Caller):@ 172.19.79.175
Video Device : /dev/video0 ( Webcam port)
Video Input : From the webcam
Video Size : QCIF
Video Bit rate : 1024Kbps
Video Transmission quality : 4 ( best possible for net meeting)
FPS : 15
Auto- Answer ,No– Gatekeeper, P-in-P enabled

27. Observations :H.263 Video and G.723 Codec Audio
Testing Over the N/W
 Quality of transmission of audio and video are quite
good.
 Video transmission is successful over H323.
 Audio transmission is successful only on one side.
(Scope for improvement).
 Video transmission on one side is getting mixed up
with unwanted frame, thus adding noise. (Scope for
improvement)
 Possible causes for Audio and Video Fine tuning::
 Camera driver compatibility and /or Portable
Windows Library upgradation required. On the go!
 ALSA core for audio to be installed. Now on OSS!

28. H.263 Video Codec Testing
 Observations
 Transfer rate of 1024 Kbps was achieved (Test) @15fps
 Statistics (for observation period of 2 min 40 sec):

Packets sent : 4201

Packets received : 1275

Packet lost : 0

Average Send time : 45 ms

Maximum Send time : 109 ms

Minimum Send time : 2

Average Receive time : 173 ms

Maximum Receive Time : 310 ms

Minimum Receive time : 1

Average jitter : 135

Maximum jitter : 212

Octets sent : 2640725

Octets received : 981652

29. Ist Half
of
May
IInd Half
of
May
Ist Half
of
Jun
IInd Half
of
Jun
Ist Half
of
Jul
IInd Half
of
Jul
Ist Half
of
Aug
System Scope
& Specification
Test Plans &
Preliminary
GUI Design
Preliminary
System
Architecture
Resource
Requirement
& Estimation
Refined
System
Architecture
Codec Evaluation Report,
Bill of Materials
Market Survey,
Feasibility,
Requirement
Capture
Conceptual
Test
Environment
Setup
Basic H/W
Requirement
Analysis,
Industry Std.
Selection
H/W & S/W
Resource
Estimation
H/W Platform
& Component
Selection
Codec Execution, Network
Protocol Simulation, Board
Procurement, CIF to 4CIF
Static Interpolation, Serial
IR Circuit Testing
IInd Half
of
Aug
Ist Half
of
Sep
IInd Half
of
Sep
Ist Half
of
Oct
IInd Half
of
Oct
Soft Simulation
Results, Test Reports,
Detail Design
Document
Technical
Specification
I
Technical
Specification
II
User Documentation,
User Manual,
Test Reports
(Comprehensive)
Integration Test Reports
Reserved For
Any leftover
Audio and Video Soft
Demos,
Reverse Engineering,
CIF to 4CIF
Interpolated
Streaming
Porting of the S/W
& Setting up the
Enviroment,
GUI Development,
Remote Control,
Camera Motion
Control
Voice Controlled
Interface,
Code optimization,
System Integration,
GUI Enhancement,
VCI Enhancement
?
TimeReportsTasksTimeReportsTasks

30. Work Allocation
1) Video Processing Programmer [GAURAV]
(+ tasks includes Digital Zoom + Horizontal Flip + 4CIF conversion)
(2) Electronics Hardware Engineer [SANTANU]
(+ tasks includes CMC + speech reorganization + echo-cancellation) + SUNIL in CMC
(3) AV CODEC + AV Drivers Programmer [SUNIL + SANTANU]
(+ tasks includes Optimizing H263 + VP3 code-optimization methods) + RAVI in
Optimizing H263
(4) Platform Engineer [ALL]
(+ tasks includes Motherboard with OS integration, maintenance, troubleshooting, etc)
(5) Network Engineer [SEAN]
For Internal Network (+ tasks includes error-concealment, adaptive transmission control)
For External Network (Not yet confirmed)
(6) Communication Engineer [SEAN + GAURAV]
(+ tasks includes joystick integration, IR + BT implementation)
(7) GUI Programmer [SUNIL + SEAN]
(8) Power Electronics Engineer [RAVI]
(+ tasks includes power supply management + Out-of-range LED + photodiode)
(9) System Integration Engineer [RAVI + SANTANU]
(+ tasks includes integration of modules/components to the platform)