1 seminar presentation multimedia audio / video communication standards instructor: dr. imran ahmad...
TRANSCRIPT
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Seminar Presentation
Multimedia Audio / Video Communication Standards
Instructor: Dr. Imran Ahmad
By: Ju WangNovember 7, 2003
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In this presentation ……
There are many standards in multimedia world
MPEG’s standards are well-known and are used everywhere
This organization – Moving Picture Experts Group, was established in 1988
MPEG family’s standards……
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MPEG-1
Code of moving pictures and associated audio for digital media at up to 1,5 Mbit/s
Became an international standard in 1993
Remarkable achievement
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Why need MPEG-1
CD-ROM enabled users to have hundreds of Megabyte storages
Interactive video applications on CD
1.5 Megabit/s was the transfer rate of CD at that time (single speed)
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Five parts in MPEG-1
Part 1 – the system
Medium specific decoder
MPEG-1 system decoder
Video decoder
Clock control
Audio decoder
Digital Storage Medium
Decoded Video
Decoded AudioMPEG-1
Stream
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Five parts in MPEG-1
Part 2, video Part 3, audio Part 4, testing Part 5, technique report for the
implementation
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MPEG-2
Generic coding of moving pictures and associated audio information
Started in 1990, became international standard in 1995
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MPEG-2’s goal
Improve the audiovisual quality of MPEG-1
Support digital TV
Compatible with MPEG-1
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MPEG-2 brought us
DVD HDTV
Because MPEG-2’s performance, the MPEG-3, whose goal was enabling HDTV, was abandoned
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Ten parts in MPEG-2
1. System 2. Video 3. Audio 4, 5. correspond to those in MPEG-1 6. Digital Storage Media Command
and control 7. Advanced audio
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10 Parts in MPEG-2
9. Real time interface for system decoder
10. Conformance test 11. IPMP in MPEG-2
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MPEG-2 vs. MPEG-1
Video quality MPEG-1: VCD MPEG-2: DVD / DTV
Audio quality MPEG-1: two (stereo) MPEG-2: multichannel
Bitrates MPEG-1: 0.8 – 2 M MPEG-2: 2 – 8 M
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MPEG-4’s goal
Provide high quality audiovisual over a large range of bitrates
Enable higher level of interaction with media content
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MPEG-4’s feature
Use “media object” to represent audiovisual content
Facilitate content-based interaction Improve the video compression
efficiency Work in a wide range of bitrate
64kbps – 4mbps
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MPEG-4’s features
Provide robustness to information errors and loss, resolution scalability, and object scalability
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MPEG-4’s applications
Internet multimedia Interactive video game Interpersonal communication Interactive storage media Wireless multimedia Broadcasting applications And more…
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MPEG-7
Multimedia Content Description Interface
Initiated in 1996, and became an international standard in 2002
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MPEG-7’s goal
Search, access, filter, retrieve, and manage audiovisual information Digital multimedia spreads Transmission speeds increase and
storage costs fall Allow higher interoperability Support a broad range of applications
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MPEG-7’s Feature
Provide a set of audiovisual description tools describe the “meaning” of the
multimedia content
The descriptions do not relay on the way the content is coded or stored
This description can be passed to, or accessed by other tools or applications
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MPEG-7’s feature
Allow different granularity in the description Creation: author, title Usage: copyright Low level feature: color, texture Conceptual: event Collection of object Interaction: user preference
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MPEG-7’s feature
The description can be extracted Automatically – only for some low level
features, like color, textual Manually – for most high level features
e.g. there are three persons in the scene
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MPEG-7’s main elements
Descriptive tools Descriptors Description schema
Description definition language System tools
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MPEG-7’s applications
Broadcast media selection Multimedia editing Home entertainments Multimedia searching, filter Much more…
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MPEG-21
Multimedia Framework
Part 2 & 3 became international standard this year
The rest of other parts are under developing
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MPEG-21’s vision & goal
Enable transparent and augmented use of multimedia resources across a wide range of network and devices to meet the needs for all users.
Its goal is to describe a big picture of how different elements to build an infrastructure for delivery and consumption of multimedia content relate to each other.
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MPEG-21’s framework
For all electronic creation, production, delivery and trade of content
Seek existing standards where appropriate
Based on two essential concepts: Digital items Users
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MPEG-21’s digital items & Users Digital Items
Can be anything from an element piece content (a single picture), to a complete collection of audiovisual work
Users Can be anyone, from authors, to vendors
to end users Users are equal, in the sense that they
all have their rights and interests in digital items
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MPEG-21’s applications
Digital library Broadcast usage Multimedia publishing & release Trade transactions Much more…
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A comparison
MPEG Standard Targeted Usage
MPEG-1 MPEG-2 MPEG-4
Coding of audio/visual content
MPEG-7 Providing metadata that describes multimedia content
MPEG-21 Providing a framework for the all-electronic creation, production, delivery and trade of content. Within the framework we can use the other MPEG standards where appropriate.
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A comparison
MPEG-1/2/4 all aim at coding of audiovisual content
MPEG-1/2 are frame-based, and MPEG-2 compatible with MPEG-1
MPEG-4 is media object-based
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A comparison
MPEG-7 will not replace the first three, it gives the contents ‘meaning’ by describing them
MPEG-21 is much broader, dealing with units that consist of multiple resources
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Other standards
H. 242, by CCITT. H.320, by CCITT QuickTime, by Apple computer, Inc. RIFF, by Microsoft and IBM RTP Much more…
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References MPEG home page: http://www.chiariglione.org/mpeg/
MPEG-1: http://www.chiariglione.org/mpeg/standards/mpeg-1/mpeg-1.htm
MPEG-2: http://www.chiariglione.org/mpeg/standards/mpeg-2/mpeg-2.htm
MPEG-4: http://www.chiariglione.org/mpeg/standards/mpeg-4/mpeg-4.htm
MPEG-7: http://www.chiariglione.org/mpeg/standards/mpeg-7/mpeg-7.htm
MPEG-21: http://www.chiariglione.org/mpeg/standards/mpeg-21/mpeg-21.htm
From MPEG-1 to MPEG-21: Creating an Interoperable Multimedia Infrastructure: http://www.chiariglione.org/mpeg/from_mpeg-1_to_mpeg-21.htm
Riding the Media Bits: http://www.chiariglione.org/ride/
ISO/IEC JTC 29 Programme of Work: http://www.itscj.ipsj.or.jp/sc29/29w42911.htm
Standards in multimedia: http://cui.unige.ch/OSG/info/MultimediaInfo/mmsurvey/standards.html
MPEG-2 FAQ at Berkeley Multimedia Research Center: http://bmrc.berkeley.edu/frame/research/mpeg/mpeg2faq.html