MPEG-4 Technology Strategy Analysis Sonja Kangas, Mihai Burlacu

Post on 22-Jan-2016

23 views 0 download

Tags:

description

MPEG-4 Technology Strategy Analysis Sonja Kangas, Mihai Burlacu T-109.551 Research Seminar on Telecommunications Business II Telecommunications Software and Multimedia Laboratory Helsinki University of Technology. Organisations Behind MPEG 4 MPEG (Moving Picture Experts Group) - PowerPoint PPT Presentation

transcript

MPEG-4Technology Strategy Analysis

Sonja Kangas, Mihai Burlacu

T-109.551 Research Seminar on Telecommunications Business II

Telecommunications Software and Multimedia Laboratory

Helsinki University of Technology

Organisations Behind MPEG 4

MPEG (Moving Picture Experts Group)

3GPP (The 3rd Generation Partnership Project)

Internet Streaming Media Alliance (ISMA)

M4IF´s (MPEG-4 Industry Forum)

Wireless Multimedia Forum's (WMF)

+ others

• Backwards compatible with older MPEG1 and MPEG2

• Object Oriented Logic support

• Deals with "media objects" ->generalization for the visual and audio content to handle both natural and synthetic objects

• Coding/decoding of the media content must not be related to any transmission medium

MPEG1• released in 1992. standard for storable multimedia, mostly for CD-ROM systems.

MPEG-1designed for compressing video, but sound compressing format (MP3) format became more popular. The typical transfer speed of MPEG-1 is VHS quality video (1,5 Mb/s).

MPEG2• released in 1994. Meant for Digital TV. Used to DVD and satelite digital

broadcast.

• Typical rates range from 1.5 Mb/s up to 24 Mb/s

MPEG4• released in 2000. Targeted for IP networks streaming applications.

• Very wide bitrate ranges from few kb/s to tens of Mb/s

Transmission/Storage Medium• Transmission/Storage Medium independent of MPEG-4 spec.

• It specifies the physical layer, digital storage requirements a.so.("raw data"

• Upper network layer (like UDP/IP, ATM, MPEG2 Transport Stream) to handle the actual physical network properties

Delivery Layer • Media object conveyed by multiple elementary streams.

• Content of the streams: audio-visual object data, scene description information, control information in the form of object descriptors

• The sync layer passes the elementary streams to delivery layer through the DMIF-application interface (DAI);

• Defined a single, uniform interface to access multimedia from a multitude of delivery technologies ((DAI) used for bringing broadcast material and local files)

• The DAI defines procedures for initializing an MPEG-4 session and obtaining access to the various elementary streams that are contained in it. Similar to ftp protocol

• FlexMux is an optional tool

• Quality of Service available to content provider. (DAI allows the user application to specify it for the necessary streams

Sync Layer

• Synch Layer handles the synchronization of elementary streams and also provides the buffering. It is achieved through time stamping within elementary streams.

• Synchronization Layer does not contain information for frame demarcation

Multimedia Layer

• Converts the multimedia elements into elementary streams.

• Difference between synthetic objects and natural objects visible at this stage

• Object descriptors : identify information type from elem streams and identify the group of streams related to a media object

• Media object carried in own elementary streams.

• The scene description information defines the spatial and temporal position of the media objects, their behavior over time

• Scene composition described with a binary language for scene description called BIFS (Binary format for scenes). Describes an efficient binary representation of the scene graph. Similar to VRML. Difference: VRML textual, BIFS binary. BIFS defined for streaming mainly. Scene sending: send initial img followed by timestamp modifications to the scene

• Upper elements make interactive applications easy to be implemented.

Dynamic Image Coding

• Static Texture Coding - done with Discrete Wavelet Transform

• Usage of reversible variable length codes.

AUDIO

• "General Audio (GA)" coders. Input signal is first decomposed into a time/frequency (t/f) spectral representation by means of an analysis filterbank, which is then subsequently quantized and coded.

• Bitrate scalability important feature

• Synthetic sound support + old traditional sound compressions tool available

Business strategies: MPEG-4 next big thing?

Expectations (industry viewpoint):

• Video to be MPEG-4’s main application area

• Industry people both servers and consumers of MPEG-4

• MPEG-4 deployment started in 2002

• Eencoder/server/player solution seems to be good idea

• Software encoders vs. hardware encoders

• Priority: performance, availability and price

• Wireless video does not lead the growth of MPEG-4

Expectations (consumers):

• What MPEG-4?

Video on mobile devices

1. The growth of data bandwidth in mobile networks

2. Improved video compression technologies

3. Improved camera and display technologies

Video applications in wireless devices

- video conference/telephony, MMS, video messanging, video streaming (advertisement, entertainment, education, communication...)

+ Media integration (multiple media): Interactive eLearning, interactive advertising, network games, media-on demand, MP3, HDTV, digital cable TV, personal video recording (PVR) etc.

An example: The mobile entertainment value web (possibilities for MPEG-4)

Areas of application

Wide: digital television, multimedia, video, audio, wireless...

Key issues

- new ways of using and accessing media

- streaming and downloading video

- interoperability

- secure communication and pay-per-view

- "mixing the best of Shockwave, Flash, VRML, and digital video into a single file format, server and player"

New business opportunities

- business opportunities for established market players and newcomers to digital video and multimedia

- MPEG-4 devices for home entertainment systems (set-top-boxes, DVD players, handheld devices...), wireless, other

- Rich (multi)media across broadcast, broadband, wireless and wired networks

- New ways of experiencing media! (compare to the content industry trends)

- Different categories of excellence (web): hw/sw, real time/non-real time -- read by the same decoders

Problems in the paradise...

+ Apple: Internet Streaming Media Alliance and other consortiums for and against

+ MPEG-4 is very extensive standard -- much more than Real and Microsoft

- The static nature of the standard is its weakness

- Future development of MPEG-4 or another standard?

- Competing video codecs: QuickTime, Real, Windows Media

- IPR issues

- patents and discoveries behing MPEG-4 (problems?)

Thank you!