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This project focuses on leveraging OpenMash and Indiva technology to improve the multicast distribution of streaming media over the MBone. By implementing innovative algorithms for stream optimization, such as removing black and blue frames, and utilizing a comprehensive toolkit of MBone tools like NSDR, VAT/RAT, and VIC, we aim to provide a robust solution for effective many-to-many communication. Future research will also explore RTP synchronization and the introduction of new streaming services, enhancing the overall experience for participants.
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NGI Summer Project Streaming Media Extensionsto Open Mash and Indiva Allan Gu
Multicast Backbone(Mbone) • Multicast • Distribution of IP packets to many hosts • Many-to-many communication • Mbone Tools • NSDR • VAT/RAT • VIC
NSDR • SAP listener • SAP announcer
VAT/RAT • Audio tool • Participants talk to each other
VIC • Viewer • Encoder
OpenMash • Comprehensive toolkit • Collection of Mbone tools • Open source
Problems • VIC displays useless stream • Save screen real estate • Save resources • Cache of multicast sessions • Web interface
Blue Stream • Camera Off • Encoder encodes default blue
Algorithm to RemoveBlue Stream • Check YUV frame • 5 blocks of 4 pixels • Compare Y, U, V with known color • Blue is (Y,U,V) = (35, 212, 114)
Black Stream • Lights Off • Can’t compare • Different black • Error not black
Algorithm to RemoveBlack Stream • Examine 20 blocks of 4 pixels each • Need more samples to detect • Count number of values within ranges • 4 BINS (3 Black, 1 Other) • Also compute average value of pixels • Black if satisfy certain condition • 50% of pixels is true black (Y<16, 120<U&V <136) • AvgY<28, 120<avgU&avgV<136
Remove Stream • Drop packets from sender • Remove thumbnail • Callback to test stream later • Accept packet and check if still black or blue • If not black or blue, put back thumbnail • If still black or blue, register another callback
Indiva: Middleware for Streaming Media Equipment and Resources • NFS metaphor • Application mounts a server and issues commands • High level commands • e.g., encode, move, copy, link, mkses, etc. • Bridge conventional audio/video environment and streaming media • Hide physical connections and control interfaces • Allocate paths through conventional routing switches • Allocate encoding/decoding resources in a broadcast center
ISAP • Cache of active Mbone sessions • Clone of NSDR • Web interface • Run continuously • Well-known address for SAP • 224.2.127.254/9875 • A web-cast guide
ISAP • Parse message according to IETF protocol • Execute indiva manager to create conference • Associate callback • After 30 minute, delete conference • Future – click link to participate in session
Future Research • RTP a/v synchronization • A “time-based corrector” for RTP packet streams • Implement new Indiva services and applications • Ncast Telepresenter service • Webcast control apps • …
Acknowledgement • NGI • Larry Rowe • Wei Tsang Ooi • Peter Pletcher • Jose Maria Gonzalez • …and the entire OpenMash community
For More Information • http://www.openmash.org • http://www.bmrc.berkeley.edu/frame/projects/indiva/