An Infrastructure for the Real-Time
Delivery of High Quality Continuous Media from Distributed Scalable Servers
to Multiple Clients
Cyrus Shahabi and Roger Zimmermann
Department of Computer Science &
Integrated Media Systems Center
University of Southern California
April 2001 report: http://infolab.usc.edu/projects/yima/nsf-itr01-report.html
April 2002 report: http://infolab.usc.edu/projects/yima/nsf-itr02-report.html
Contact
Information
Cyrus Shahabi
University of Southern California
Computer Science Department SAL 300
Los Angeles, CA 90089-0781
Phone: (213) 740-8162
Fax : (213) 740-5807
Ph.D. Students: Farnoush Banaei-Kashani, Kun Fu, Mehrdad Jahangiri, and Didi Yao
Yima 2001 Demonstration Video
Video Clip for Yima's Introduction
Yima Project: http://idefix.usc.edu/projects.html
Remote Media Immersion (RMI): http://imsc.usc.edu/rmi/
Project
Award Information
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Award Number: ITR-0082826
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Duration: 09/01/2000 -- 08/31/2003
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Title: An Infrastructure for the Real-Time Delivery of High Quality
Continuous Media from Distributed Scalable Servers to Multiple Clients
Project
Summary
Several large-scale IT applications are enabled by the design, implementation
and evaluation of a scalable real-time streaming media architecture. Large
volumes of real-time data are stored, maintained, and retrieved online.
Popular examples of real-time media include video and audio, while less
familiar examples are haptic and avatar data. The real-time end-to-end
delivery of very high quality (megabits per second) media cannot be supported
with the current Internet-based infrastructure due to the lack of a scalable
server architecture as well as a missing global resource management protocol.
We are in the process of completing the design and implementation of
our Yima
streaming architecture, which consist of 1) a scalable, high performance,
and real-time media server, 2) real-time network streaming paradigm and
3) several video and audio clients.
In addition, we are working on the design and implementation of GMeN
(Global Media Network), a server-level distributed streaming architecture
for cost-efficient delivery of continuous media to geographically distributed
clients. Also, with P2PS (Peer-to-Peer Streaming) we investigate the
client-level distribution of service that pushes the streaming task
to the edges/users.
The impact of this architecture is on both the server design as well
as the online multimedia content. Furthermore, the realization of such
an infrastructure is enabling large scale applications such as video-on-demand,
news-on-demand, distance learning and scientific exploration and visualization.
These applications, in turn, will be promoting teaching, training, and
learning as well as enhancing scientific and technological understanding.
Features of Yima Streaming Server:
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Multi-node, scalable server architecture
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Media format independent: supports DVD MPEG-2 (8 Mb/s), HD MPEG-2 (20 Mb/s),
MPEG-4 (800 Kb/s), 10.2 channel audio, etc.
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Standard transmission protocols: RTP, RTSP
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Selective retransmission of lost media packets for improved playback quality
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Synchronization across multiple media streams

Project
Impact
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Super-streaming has been licensed to BTG Inc.; Yima
Jade, RedHi-DM, and SCADDAR have been licensed to The GlobalTheater Inc
(http://www.theglobaltheater.com).
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A research license for Yima Jade has also been provided to Wong's International
USA Corp.
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A test installation of Yima server has been operational at The GlobalTheater
since October 2000.
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A multimedia lecture on Super-streaming has been developed as a CD-ROM
and distributed as part of the "CSCI-585: Database Systems" course within
the Computer Science Department of the University of Southern California.
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Several research prototypes of Yima (with different clients) have been demonstrated
to NSF and industry visitors of the USC's Integrated
Media Systems Center , an NSF Engineering Research Center. A
major press release and demonstration of the IMSC's RMI (Remote Media Immersion)
experiment that is scheduled for May 2002 will include Yima as its main
streaming infrastructure.
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Yima’s performance has been evaluated in realistic setups by co-locating
it in an IMSC industry partner, AboveNet Inc., data center at El Segundo,
CA.
Yima explorations with Dr.
Jim Gray
Jerry Campbell (USC's Chief Information Officer) watching DVD
quality (MPEG-2 @ 8 Mb/s) streaming from Yima-1
Goals,
Objectives, and Targeted Activities
The goal of this project is to design
and develop an architecture for real-time storage and playback of several
continuous media streams through heterogeneous, scalable and distributed
servers utilizing IP networks (e.g., Internet). This architecture enables
applications such as video-on-demand, employee training and distance learning
on a large scale.
The main component of our architecture
is a scalable media server, termed Yima. Yima is based on a cluster
design comprised of multiple nodes of off-the-shelf personal computers
resulting in both a scalable and cost-effective implementation. The
network component of our architecture provides a selective retransmission
scheme that improves the rendering quality of the transmitted streams with
real-world networks that suffer from occasional packet loss. This scheme
is shown to be more effective for real-time media as compared to conventional
UDP and TCP schemes. Yima's SCADDAR algorithm allows incremental
storage system growth while (a) the system continues operation, (b) the
minimal amount of data is reorganized, and (c) the system continues to
be load balanced. Finally, we are investigating a distributed architecture
that consists of several Yima server nodes inter-connected through a controlled
network. We have discovered that a decentralized management of the
media objects (e.g., video clips), as opposed to a centralized (e.g., directory-service)
design, results in more efficient and robust architecture. This fully decentralized
design is also consistent with the recently popular peer-to-peer architectures.
We have developed a working prototype
of Yima that is designed to be media independent to stream media types
such as MPEG-4, uncompressed immersive audio, panoramic (360 degree) video
and High Definition TV. Our Multi-Threshold Flow Control (MTFC) algorithm
allows the smoothing of variable bit-rate media transmissions without a
priori knowledge of the actual bit-rate. It improves resource utilization
and can be applied to (a) live streams and (b) stored streams without requiring
any server side pre-processing. We have also shown the ability of Yima
to allow multiple streams be rendered in tight synchronization over the
public Internet. For example, panoramic video streams that are comprised
of five individual streams can be displayed frame-locked.
Yima distinguishes itself from other similar
efforts due to its: 1) independence from media type, 2) frame/sample accurate
inter-stream synchronization, 3) compliance with industry standards (e.g.,
RTSP, RTP, MP4), 4) selective retransmission protocol, 5) scalable design,
and 6) multi-threshold buffering to support variable-bitrate media (e.g.,
MPEG-2).
Major Milestones Reached
- May 2000, Design and implementation of Yima-1 complete
- March 2001, Residential Broadband Experiment
- May 2001, Design and implementation of Yima-2 complete
- June 2001, Design of disk scaling technique, SCADDAR, complete
- July 2001, IMSC's Multi-Channel Experiment
- November 2001, Design and implementation of Multi-Threshold Flow Control (MTFC) complete
- January 2002, Successful streaming of 10.2 channels of synchronized audio
- February 2002, Implementation of SCADDAR complete
Publications: (Acknowledges this NSF ITR grant)
- Roger Zimmermann, Kun Fu, Nitin Nahata, and Cyrus Shahabi, Retransmission-based error control in a many-to-many client-server environment,
SPIE/ACM Conference on Multimedia Computing and Networking (MMCN 2003), Santa Clara, CA, January 2003
- Cyrus Shahabi, Roger Zimmermann, Kun Fu, and Shu-Yuen Didi Yao, Yima: A Second Generation
of Continuous Media Servers, IEEE Computer Magazine, June, 2002
- Cyrus Shahabi, Farnoush Banaei-Kashani, Decentralized Resource Management
for a Distributed Continuous Media Server, IEEE Transactions on Parallel
and Distributed Systems, Vol. 13, No. 6, June 2002
- Cyrus Shahabi, Shahram Ghandeharizadeh, Surajit Chaudhuri, On Scheduling Atomic and Composite Multimedia Objects
, IEEE Transactions on Knowledge and Data Engineering, Vol. 14, No. 2, pages 447-455, March/April 2002
- Ashish Goel, Cyrus Shahabi, Shu-Yuen Didi Yao, and Roger Zimmermann, SCADDAR: An Efficient Randomized Technique to Reorganize Continuous Media Blocks,
International Conference on Data Engineering 2002, San Jose, California, February 2002
- Roger Zimmermann, Kun Fu, Cyrus Shahabi, Didi Yao, Hong Zhu, Yima: Design and Evaluation of a Streaming Media System for Residential Broadband Services
, VLDB 2001 Workshop on Databases in Telecommunications (DBTel 2001), Rome, Italy , September 2001
Other publications which acknowledge this NSF ITR grant (only those dated post September 2000)