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Multimedia Lab.

Multimedia Communication

DongSun Park

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Multimedia Lab.

Internet 구성

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Multimedia Lab.

Network 의 종류 ( 규모 )

• 규모에 따른 네트워크 구분

BAN PAN

LAN

MAN

WAN

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Multimedia Lab.

Network 의 종류 ( 정의 )

• BAN : Body Area Network 사람이 착용하는 옷이나 , 인체에 부착된 디바이스로 구성된 네트워크

• PAN : Personal Area Network 근거리의 컴퓨터와 주변기기 , 이동단말기 등을 연결하여 구성한 네트워크

• LAN : Local Area Network 다수의 독립된 컴퓨터들이 상호간에 통신이 가능하도록 하는 데이터 통신

시스템으로 가까운 지역 내의 한정된 네트워크

• MAN : Metropolitan Area Network 여러 개의 LAN 을 포함하는 도시를 근간으로 한 네트워크

• WAN : Wide Area Network LAN 이 여러 개 모여서 그들간에 고속 전송이 가능한 전용 회선으로 연결된

광대역 네트워크

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Multimedia Lab.

Network 의 종류 ( 예제 )

• BAN : Body Area Network MICS, ZigBee, Bluetooth

• PAN : Personal Area Network ZigBee, Bluetooth

• LAN : Local Area Network Ethernet, WirelessLAN(802.11)

• MAN : Metropolitan Area Network FDDI, DQDB, ATM

• WAN : Wide Area Network HDLC, PPP, Frame Relay, ATM

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Multimedia Lab.

네트워크의 속력 (Bandwidth)

인터넷 접속방법 연결회선 회선속도 접속장비

모 뎀 전화선 56 Kbps 모뎀

LAN 전용선 56Kbps ~ 100Mbps

랜카드

ISDN 전화선 64Kbps ∼128Kbps ISDN 모뎀

케이블 TV 케이블 망 최대 10Mbps 케이블 모뎀

xDSL 전화선 600Kbps∼50Mbps xDSL 모뎀

인공위성전화선 , 전용선 및위성링크

최대 3Mbps위성수신안테나 ,

위성수신용 PC 카드

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Multimedia Lab.

네트워크의 속력 (Bandwidth)

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Multimedia Lab.

JPEG 2000

영상 부호화 국제 표준화 기구

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Multimedia Lab.

JPEG 2000

영상 압축 표준 방식의 발전 과정

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Multimedia Lab.

JPEG 2000

JPEG2000 Block Diagram.

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Multimedia Lab.

① Low bit-rate compression performance② Lossless and lossy compression③ 화소 정확도와 해상도에 의한 점진적 전송④ 관심영역 부호화⑤ Random codestream access and processing ⑥ Error resilience⑦ Open architecture ⑧ 컨텐츠 기반의 기술 , 영상 보호⑨ Side channel spatial information⑩ 연속톤 (continuous-tone) 과 2 중 레벨 (hi-level)

의 압축

JPEG 2000 의 특징

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Multimedia Lab.

• Part 1.Core Coding System• Part 2. Extension• Part 3. Motion JPEG2000• Part 4. Conformance• Part 5. Reference Software• Part 6. Compound Image File Format• Part 7.• Part 8. JPSEC(Security Aspects)• Part 9. JPIP• Part 10. JP3D• Part 11. JPWL(Wireless Applcations)• Part 12. ISO based Media File Format• Part 13. Entry level JPEG2000 Encoder

JPEG 2000 Spec.

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Multimedia Lab.

2

JPEG 2000 - DWT

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Multimedia Lab.

2 차원 대역 분할

JPEG 2000 - DWT

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Multimedia Lab.

Tier – 1 : BPC 와 BAC 로 구성 되어 있음 . BPC : 19 가지의 group 으로 구분 , 압축 할 수 있는 source 제공 BAC : Group 화된 정보의 확률 값을 이용하여 압축 실행 .

EBCOT (Tier-1)

JPEG 2000 - EBCOT

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Multimedia Lab.

Jointly developed by ITU-T and MPEG.

Upto 50% more efficient at the same virtual quality compared to MPEG-4 ASP

Supports wide range of applications. (interlaced, progressive, low bit-rate, studio quality digital cinema etc).

Multiple profiles (Baseline, Main, Extended, High, FRExt).

Good results obtained from interoperability tests making it suitable for wide deployment in short span of time.

H.264 Background

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Multimedia Lab.

H.264 Encoder Block Diagram

[Single Universal VLC and Context Adaptive

VLC] OR

[Context-Based Adaptive Binary

Arithmetic Coding]

Intra Prediction Modes9 4x4 & 4 16x16 modes = 13

modes

•Seven block sizes and shapes•Multiple reference picture

selection•1/4-pel motion estimation

accuracy•Referenced B-frames

Intra

Inter_

Video Source Transfor

m

Bit Stream Out

Quantized Transform Coefficients

Motion Vectors

+

Predicted Frame

Quantization

Entropy

Coding

Motion Estimation

Frame Store

Motion Compensation

InverseQuantization

InverseTransform

+

Coding Control

Loop Filter

+

Intra Prediction

Integer 16-bit fixed point transform with no

mismatch

Quantization step more resolution for finer control of

bit rate

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Multimedia Lab.

A coded sequence contains one or more access units An access unit is a set of NAL units that contains all necessary information for decoding exactly one (primary) coded picture

A coded picture is divided into Slices (VLC NAL units) A slice contains a slice header and a set of macroblocks A macroblock contains a 16x16 luma block and two chroma blocks An I-slice contains a set of INTRA-coded macroblocks A P-slice contains a set of INTRA- and INTER-coded macroblocks An IDR (instantaneous decoding refresh) picture contains only I-slices (SI-slices too in extended profile)

High Level Tools: Coding Hierarchy

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Multimedia Lab.

Every macroblock can be split in one of 7 ways for improved motion estimation

Accuracy of motion compensation = 1/4 pixel

Up to 5 reference frames for SDTV size @ L3

Weighted predictions

Reference B pictures

CurrentMacroblockor Partition

or Block

A

B CD

Enhanced MC (Inter Prediction)

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Multimedia Lab.

Block Scanning Order in a MB

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Multimedia Lab.

Deblocking filter

Frame / Field Adaptation

Picture Adaptive Frame Field (PicAFF).

Macroblock Adaptive Frame Field (MBAFF)

Field scan and zig-zag scan options

Zig-zag Frame Scan Field Scan

Interlaced Coding

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Multimedia Lab.

Universal Variable Length Coding (UVLC) using Exp-Golomb codes.

Context Adaptive VLC (CAVLC)

Context Adaptive Binary Arithmetic Coding (CABAC)

Entropy Coding

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Multimedia Lab.

Frame Fn Frame Fn-1

16x16 Motion Vectors

Residual Fn – Fn-1Motion Compensated

ReferenceMotion Compensated

Residual

Courtesy : Images from H.264 and MPEG-4 Compression – Ian Richardson

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Multimedia Lab.

Coding Efficiency

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Multimedia Lab.

Feature/Standard MPEG-1 MPEG-2 MPEG-4 part 2 (visual)

H.264/MPEG-4 part 10

Macroblock size 16x16 16x16 (frame mode)

16x8 (field mode)

16x16 16x16

Block Size 8x8 8x8 16x16, 16x8, 8x8 16x16, 8x16, 16x8, 8x8, 4x8, 8x4, 4x4

Transform 8x8 DCT 8x8 DCT 8x8 DCT/Wavelet

4x4, 8x8 Int DCT

4x4, 2x2 Hadamard

Quantization Scalar quantization with

step size of constant

increment

Scalar quantization with step size of

constant increment

Vector quantization

Scalar quantization with step size of

increase at the rate of 12.5%

Entropy coding VLC VLC VLC VLC, CAVLC, CABAC

Motion Estimation & Compensation

Yes Yes Yes Yes, more flexible

Up to 16 MVs per MB

Playback & Random Access

Yes Yes Yes Yes

Comparision of Standards

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Multimedia Lab.

Feature/Standard MPEG-1 MPEG-2 MPEG-4 part 2 (visual)

H.264/MPEG-4 part 10

Pel accuracy Integer, ½-pel Integer, ½-pel Integer, ½-pel, ¼-pel

Integer, ½-pel, ¼-pel

Profiles No 5 8 3

Reference picture one one one multiple

Bidirectional prediction mode

forward/backward forward/backward forward/backward forward/forwardforward/backward

backward/backward

Picture Types I, P, B, D I, P, B I, P, B I, P, B, SP, SI

Error robustness Synchronization & concealment

Data partitioning, FEC for important

packet transmission

Synchronization, Data partitioning, Header extension, Reversible VLCs

Data partitioning,Parameter setting,

Flexible macroblock ordering, Redundant slice, Switched slice

Transmission rate Up to 1.5Mbps 2-15Mbps 64kbps - 2Mbps 64kbps -150Mbps

Compatibility with previous standards

n/a Yes Yes No

Encoder complexity Low Medium Medium High

Comparision of Standards (cont’d..)

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Multimedia Lab.

Multimedia System 1

• IMD System BAN 과 2 차 Network 를 이용하여 정보 전송

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Multimedia Lab.

Multimedia System 2

• Wireless CCTV CCTV 와 관리시스템을 무선으로 연결 동영상 압축 코덱을 JPEG2000 을 이용하여 ROI 가능

Wireless Lan원본 영상 디스플레이

Memory

Transceiver

Storage

Transceiver

JPEG2KH.264

JPEG2KH.264

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Multimedia Lab.

Multimedia System 3

• IPTV 서비스 인터넷망을 통한 TV 서비스