Transcript MPEG-4 - Computer Science and Engineering

MPEG 4
Shaojie Zhang
Anjum Gupta
Dept. of Computer
Science and Engineering
Outline
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Overview
Technical Detail
Industry and Market
Conclusion
Overview
• MPEG-1 - Error free environments
• MPEG-2 - Broadcast TV (SD and HD)
• MPEG-4 - Object based coding
• MPEG-7 - Multimedia description
• MPEG-21 - Seven element initiative for multimedia deployment
What is MPEG-4
• An open toolbox to build
bitstreams and decoders
for multimedia content:
• Synthetic interactive
graphics content
• To accommodate various
user devices
• Lower bit rate encoding
MPEG 4 – Basic Approach
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Object Based Encoding
– MPEG-4 audiovisual scenes are composed of
several media objects.
• Still objects (e.g. fixed background)
• Video objects (e.g. a talking person)
• Audio objects
Encoding Example
An example of an MPEG-4 Scene
Scene Description Format
• An MPEG-4 scene
structure is represented
as a DAG.
• Each node is a media
object.
• Multiplexed with the
media objects.
Flexibility within MPEG-4
• Various algorithms to handle special cases.
• The stream is made of atomic units called
Video Objects (VOs).
• Audio Visual Objects (AVOs) are combined
to create a scene.
Bit rate variability
Generic coder is extended by adding “Shape” input.
Coding Tools and Algorithms
VLBV (Very Low Bit-rate Video) core can be extended by adding more information.
MPEG-4 Encoding
Decoding
An Application
Companies having MPEG-4 products
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Index of Companies
Ahead Software
Amphion Semiconductor
Apple Computers
Bitmanagement Software
GmbH
5. Dicas Digital Image Coding
GmbH
6. DivXNetworks, Inc.
7. Emblaze Research
8. Envivio
9. Equator Technologies, Inc.
10.Fraunhofer Institute IIS-A
11.Hantro Products Oy
12.Harmonic Inc.
13.iVAST Inc.
14.Nextreaming Corporation
15.Octaga AS
16.Philips Electronics
17.Prodys
18.Sci-worx GmbH
19.Sorenson Media
20.Soundball, Inc.
21.Toshiba
22.Tvia, Inc.
23.VBrick Systems, Inc.
24.VCS Video Communication
Systems AG
25.VideoSpheres Inc.
26.Xilinx Inc.
MPEG Market Penetration
US Market Penetration – growth from year 0 (introduction) – 10
(From: The Yankee Group).
MPEG Media Distribution
US Video-On-Demand Subscriber Forecasts
(From: The Yankee Group)
MPEG 4 Vs Other Technologies
Conclusion
• MPEG-4 enables very low bit-rate
multimedia communications.
• MPEG-4 is a dynamic standard, that is
continuously being improved.
• Is being accepted in the industry
applications.
• Expanding demand in the market.
References
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ISO/IEC JTC1/SC29/WG11 N4668
ISO/IEC JTC 1/SC 29/WG 11N2826
ISO/IEC JTC 1/SC 29/WG 11N5504
MPEG-4 Industry Forum (http://www.m4if.org)
Acknowledgement
• Dr. Wo Chang, NIST, U.S.
• Dr. Kai-Kuang Ma, NTU, Singapore