Kaushal Patel | kaushalp@andrew.cmu.eduKeshav Seshadri | kseshadr@andrew.cmu.eduSumedha Swamy |sumedhas@andrew.cmu.edu

ProjectReal Time ProtocolSystem ImplementationDemoPerformance AnalysisCh llChallengesPossible Improvements

Camera

Portable Computer

Wireless Channel

Computer

Wireless Access PointMain Computer

Camera640 480 i l i

Subject

◦ 640x480 pixel images◦ 7.5-30 frames/sec802.11g Network802.11g NetworkEnd-to-end video streaming system.

Pupil MonitoringH i l d i l i i◦ Horizontal and vertical position◦ Torsional position◦ Pupil sizePurpose◦ Diabetic Retinopathy*◦ Several medical diagnosis including Balance◦ Several medical diagnosis including Balance

DisorderOther applications

* X. Long, O.K. Tonguz, and A. Kiderman, “Real Time Pupil Size Monitoring As a Screening Method for Diabetic Retinopathy”, Accepted for IEEE Biomedical Circuits and System Conference Nov. 27-30 2007 (BIOCAS 2007), Montreal, Canada.

Gathering images Displaying each g gfrom the Point Gray

Camera

gframe in the picture

box

Isolating each frame and break it down in

ll k

Forming the complete frame and listening for more

Sender Receiver

smaller packets listening for more packets

Sending each packet using RTP library

Receiving packets, checking for end-of-

frame

Software Architecture - Sender High Level View

Goggles Sender Application

Network Socket A Network Socket B

Goggles Driver Interface

FlyCap JRTPLIB JTHREAD

Microsoft .net + Win32

Software Architecture - Receiver

T1 : Compressed Image T2 : Un-compressed Image

Event Event

T3 : Display Interface

Low Level Interface

Real Time ?Reliable ?Why use it?

C l M h i◦ Control Mechanism◦ Time Stamp◦ RFC 3016 is our friendI’m old school. I’ll use TCP◦ No! And here’s why :

D ’ f iDon’t force receptionGood luck with multicastCongestion Control

Sit back, relax and enjoy the demo.

Interfacing PGRFlyCapture libraryMicrosoft .NET frameworkMulti Thread applicationEvent-driven programming

Sender and Receiver in the same room

Camera FPSThroughput

(kbps)Packets/sec Frames/sec

TX RX TX RX TX RX3.75 450 440 40.1 40.0 3.74 3.72

15 680 660 61.9 61.2 6.21 6.14

30 670 650 60.3 59.6 6.15 6.01

Sender and Receiver in the separate rooms

Camera FPSThroughput

(kbps)Packets/sec Frames/sec

TX RX TX RX TX RX3.75 510 490 46.1 43.6 3.72 3.56

15 690 630 62.8 59.7 6.46 6.20

30 690 640 61.8 57.1 5.74 5.41

Pre-processing◦ Region of Interest◦ Various compression mechanismsSystemSystem◦ Frame rate◦ Non-identical RTP channels Application◦ GUI

B id di l◦ Better video display