# Lecture 5: Video Compression Standards (Part2) Tutorial 3 : Introduction to Histogram

Size: px
Start display at page:

Download "Lecture 5: Video Compression Standards (Part2) Tutorial 3 : Introduction to Histogram"

## Transcription

1 Lecture 5: Video Compression Standards (Part) Tutorial 3 : Dr. Jian Zhang Conjoint Associate Professor NICTA & CSE UNSW COMP9519 Multimedia Systems S 006 Introduction to Histogram Image Histogram 4. Digital Video Coding (DVC) Structure Hybrid MC/DPCM/DCT --Tutorial diff input MC Encoder COMP9519 Multimedia Systems Lecture 5 Slide 3 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 4 J Zhang Rec

2 Block Based Estimation Tutorial Block base search Block Based Estimation Tutorial Block base search Reconstructed Frame Reconstructed Frame Compensated Frame Vector W=Search Range 16 Vector W=Search Range W 16 W W W 16 W 16 W Search Window Position of Current Block 16x16 -- Macroblock Search Window Position of Current Block Compensated MB 16x16 -- Macroblock COMP9519 Multimedia Systems Lecture 5 Slide 5 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 6 J Zhang Information Entropy Tutorial Histogram & Entropy--Tutorial Information Entropy: The Entropy is defined as the average information content per symbol of the source. The Entropy, H, can be expressed as follows: Look at a source that contains m possible symbols: {si, i=1,..m}. The occurrence probabilities: {Pi, i=1,..m}, So The info. content of a symbol si; = i( s ) = log p bits I i i The entropy of an information source is a function of occurrence probabilities. The entropy reaches the Max. when all symbols in the set are equally probable. H = m i = 1 p i log p i i bits Entropy = 7.63 bits/pixel Calculate: P1, P..Pm. H = m i = 1 p i log p i COMP9519 Multimedia Systems Lecture 5 Slide 7 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 8 J Zhang

3 Key operations in image/video coding -- Tutorial A -dimentional transform can be extended T T according to :[C] = [C ][T] =[T] [F][T] Key operations in image/video coding -- Tutorial Discrete Cosine Transform For a -D input block U, the transform coefficients can be found as T Y = CUC T The inverse transform can be found as U = C YC The NxN discrete cosine transform matrix C=c(k,n) is defined as: 93% of energy now in one term that is in position (0,0) c( k, n) = 1 N for k = 0 and 0 n N 1, π (n + 1) k cos for1 k N 1and 0 n N 1. N N [1] Do you get any hint to do DCT transform for a 8x8 block? COMP9519 Multimedia Systems Lecture 5 Slide 9 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 10 J Zhang Key operations in image/video coding --Tutorial Quantization weighting matrix (QWM) Diff quantizers for diff. DCT Coef. Default Qant. QWM C ij = 16 * C Recommended MPEG quantization matrix [] Quantization results of the DCT coefficients, you can choose an appropriate quantization step-size Q {4,3}. W-Matrix. You need to tell the Q value and the QWM (left or right?) COMP9519 Multimedia Systems Lecture 5 Slide 11 J Zhang Quantized Setpsize Coef.ij ij //( Q * W weighting ij ) Key operations in image/video coding -- Tutorial The distribution of -D DCT Coefficients after the quantization 51 [3] Run-length (Zig-zag) results COMP9519 Multimedia Systems Lecture 5 Slide 1 J Zhang Ref: H. Wu Zig-Zag scan

4 Key operations in image/video coding -- Tutorial DC coefficient is coded differentially as (size, amplitude). There are 1 categories of size Key operations in image/video coding -- Tutorial Zig-Zag scan 11 Note: We have block0; block1; block; block3. The predicated DC value for block0 is 0 The predicated DC value for block1 is the DC value of block0 COMP9519 Multimedia Systems Lecture 5 Slide 13 J Zhang [4] VLC of the Zig-zag scan run-length pairs for the four 8x8 sub-image blocks COMP9519 Multimedia Systems Lecture 5 Slide 14 J Zhang Digital Video Coding (DVC) Structure Video Block Structure Tutorial Typical MC/DPCM/DCT video coding architectures use the 4::0 (YCbCr) format as block data structure The architecture consists of the following layered data structure for each picture: Picture layer Slice or group of blocks (GOB) layer Macroblock (MB) layer: 16x61 pixels 4Y,Cb & Cr Block size layer: 8x8 pixels.. MC is applied to the MBs. Ref: H. Wu Digital Video Coding (DVC) Tutorial Standards MPEG-1 (ISO/IEC 1117) Coding order: 0,3,1,,6,4,5,9,7,8 Intra coded picture (I-Picture): Coded on their own (all MBs are intra) and server as random access. Predicted picture (P-Picture): Coded with reference (MC predictions) to the previous anchor I or P picture. Bidirectionally predicted picture (B-Picture): Coded with reference to the previous and/or future anchor I or P pictures (forward or backward MC prediction and/or linear interpolation). COMP9519 Multimedia Systems Lecture 5 Slide 15 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 16 J Zhang

5 Digital Video Coding (DVC) Tutorial Standards MPEG- Scalability Digital Video Coding (DVC) Tutorial Standards MPEG- Scalability SNR Scalability (mode encode) 16x16 16x16 8x8 layer spatially scalable coder COMP9519 Multimedia Systems Lecture 5 Slide 17 J Zhang Spatiotemporal weighted Prediction in Spa-Scal.+ Pred COMP9519 Multimedia Systems Lecture 5 Slide 18 J Zhang Drift will not be to the enhanced layer This is because that the diff. refinement coef. do feed back into the lower MC Pred loop at the encoder However, the drift will be introduced once the error or packet loss is occurred in the enhanced layer. Standards MPEG- Error Resilience Most digital storage media and communication channel are not error free. Channel coding is beyond the scope of the MPEG specification The compression scheme needs to robust to residual errors The error resilience schemes can be applied in both sides Encoder/decoder The slice structure of MPEG allows resync. after an error to limit the bit errors within a certain area Decoders may also attempt to conceal the effect of errors Five major parts form the prevision of error resilience Error Detection: It is desirable to detect quickly that an error has occurred and immediately take steps to prevent catastrophic degradation in video quality. Error detection can be based on a syntactic or a semantic basis such as illegal VLC, more 64 DCT coef. etc. Resynchronization: When synchronization is lost with the arriving bitstream, the decoder will normally go looking for a unique resync. codeword The resync. word is followed by sufficient data to allow the decoder to continue the decoding process from that point recovery: It explores to find the boundary of corrupted bitstream and then determine if the regain for decoding is utilized COMP9519 Multimedia Systems Lecture 5 Slide 19 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 0 J Zhang

6 Temporal/Special Localization: It prevents the error propagation by inserting regular intra coded picture, slides or macroblocks due to any transmission error. Two type of error propagations: temporal error propagation errors are propagated into next frames spatial error propagation errors are propagated within a video picture Concealment: The impact of any errors can be concealed using correctly decoded information from the current or previous pictures Conclusion: While all of the previous parts are important, the use of effective error concealment will lead to the greatest improvement in subjective quality of decoded for error corrupted bitstreams The impact of errors within decoded picture Original picture Error damaged picture COMP9519 Multimedia Systems Lecture 5 Slide 1 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide J Zhang Concealment Techniques Spatial concealment: Concealment Techniques Spatial concealment: Simple interpolation with above/below slices This technique is best suited to little spatial activity but is far less successful in areas where there is significant spatial details. Error damaged picture Spatial concealed picture COMP9519 Multimedia Systems Lecture 5 Slide 3 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 4 J Zhang

7 Concealment Techniques Simple temporal concealment The impact of errors within decoded picture Previous frame Current frame This technique is effective in the relatively stationary area but much less effective in the fast moving background Error damaged picture Temporal concealed picture COMP9519 Multimedia Systems Lecture 5 Slide 5 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 6 J Zhang Concealment Techniques compensated concealment It combines both temporal replacement and motion estimation High correlation among nearby MVs in a picture The assumption is the linear changes on MVs from the below to above MBs. It has been proven that this scheme can improve significantly error concealment in moving areas of the picture Concealment Techniques compensated concealment Encoder has option to transmit the concealment MVs with Intra-coded MB if they are above/below a corrupted MB Lost MB COMP9519 Multimedia Systems Lecture 5 Slide 7 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 8 J Zhang

8 Temporal Localization Cyclic intra-coded pictures Temporal Localization Cyclic intra-coded slices I Extra intra-coded I-pictures can be sent to replace B or P- pictures. Error propagation can be reduced at the cost of extra overhead in the bitstream This scheme will reduce the coding efficiency Extra intra-coded I-slides can be used to periodically refresh the frame from the top to the bottom over a number of frames The disadvantage is that the partial updating of the screen in a frame period will produce a noticeable windscreen wiper effect COMP9519 Multimedia Systems Lecture 5 Slide 9 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 30 J Zhang Temporal Localization Cyclic intra-coded marcoblock (MB) refreshment A fixed number of frames Spatial Localization Small Slices Mode (slice mode in MPEG-4 or H.63) The 11MBs or MBs per slice can reduce the damage to decoded picture after a corrupted MB is detected.. Extra intra-coded MBs can be inserted to refresh the frame periodically over a fixed number of frames This scheme has been widely used in current MPEG-4 codec COMP9519 Multimedia Systems Lecture 5 Slide 31 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 3 J Zhang

9 Spatial Localization Small Slices Mode (slice mode in MPEG-4 or H.63) Some significant factors impact on the number of bits required to code a slice in a picture (coding mode, picture activities etc.) Spatial Localization Fixed Bits Payload (Adaptive Slice Mode) The disadvantage of the small slice mode does not take into account of the packing structure to accommodate one slice per packet The fixed bits payload adaptive slice mode addresses the weak point caused by small slice Bad Case Good Case COMP9519 Multimedia Systems Lecture 5 Slide 33 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 34 J Zhang The Combination of Error Resilience Schemes Spatial interpolation Simple marcoblock temporal replacement Small slice mode Adaptive slice mode Small slice mode + compensated concealment Advanced error concealment J. Zhang, M.R. Frater and J.F. Arnold A Cell Loss Concealment Technique for MPEG Coded Video, IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY, VOL. 10, NO. 4, pp , JUNE 000. Layered Coding for error concealment Base layer important data/information High layer less important Layered Coder High Priority Low Priority Low Loss Channel High Loss Channel X X It applies to Spatial Scalability, SNR Scalability and Partitioning Scalability & Frequency Scalability COMP9519 Multimedia Systems Lecture 5 Slide 35 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 36 J Zhang

10 5.1 Demo for Error Resilience Demo 5. Introduction to MPEG-4 Standard New Functionalities & Associated Application for MPEG-4 Content-based Multimedia base searching Video Games 3-D movies Content-based Interactivity Improved Coding Efficiency Video telephone Video streaming Video aurthoring Mobility access Remote Monitoring Wireless LAN Universal Access COMP9519 Multimedia Systems Lecture 5 Slide 37 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 38 J Zhang 5. Introduction to MPEG-4 Standard 1. Systems Defines the architecture, multiplex and syntax of the MPEG-4 standard. Syntax component for configuring decoders with multiple coding tools Defining the compositing operation permitted by decoders for user interaction. Video Define the video coding algorithms and tools (normative parts) specifies the coding and animation of synthetic and natural hybrid video (SNHC) 3. Audio 4. Conformance Testing 5. Technical Report Software codec specification 6. DSM-CC Multimedia integration framework 5.3 MPEG-4 visual standard Video Coding and Communication MPEG-4 standard: video part -- content based video coding scheme To enable all these content-based functionalities, MPEG-4 relies on a revolutionary, content based representation of audiovisual objects. As opposed to classical rectangular video (eg: MPEG1/), MPEG-4 treats a scene as a composition of several objects that are separately encoded and decoded The scalability at the object or content level enables to distribute the available bit-rate among the objects in the scene Visually, more important objects are allocated more bits. Encoded once and automatically played out at different rates with acceptable quality for the communication environment and bandwidth at hand. COMP9519 Multimedia Systems Lecture 5 Slide 39 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 40 J Zhang

11 Major Functionalities in MPEG-4 Visual Standard Compression: Improved Coding Efficiency Coding of Multiple Concurrent Streams Content-Based Interactivity: Content-based Manipulation and Bitstream Editing Hybrid Natural & Synthetic Coding Improved Temp. Random Access COMP9519 Multimedia Systems Lecture 5 Slide 41 J Zhang Universal Access: Content-based Scalability in Textures, Image and Video Complexity scalability for en/de Spatial scalability Temporal scalability Quality scalability Fine grain scalability Shape & Alpha Channel Coding Robustness in Error-Prone Environments Access and manipulation of arbitrarily shaped images Ref: Thomas Sikora Object Based MPEG-4 Video Verification Model 1. In MPEG-4, scenes are composed of different objects to enable contentbased functionalities.. Flexible coding of video objects 3. Coding of a Video Object Plane (VOP) Layer COMP9519 Multimedia Systems Lecture 5 Slide 4 J Zhang Video Object Planes (VOP s) Ref: Thomas Sikora Decomposition into VOP s Ref: Thomas Sikora Original Binary Segmentation Mask Background Layer VOP Foreground Layer VOP The binary segmentation Mask is to extract the back/fore-ground layers The overlapping VOP s brining the opportunity to do the manipulation of Scene content Ref: MPEG-4 AKIYO testing video sequence COMP9519 Multimedia Systems Lecture 5 Slide 43 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 44 J Zhang

12 Video Object Plane layered coding Arbitrary VOP Shape MPEG-4 VOP-coder (MV) Ref: Thomas Sikora Texture DCT bitstream DCT-Based Approach for Coding VOP s Ref: Thomas Sikora Similar to H.63 Rectangular VOP (MV) Similar to H.63 Texture DCT bitstream Block diagram of the basic MPEG-4 hybrid DPCM/transform codec structure COMP9519 Multimedia Systems Lecture 5 Slide 45 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 46 J Zhang Coding of a Video Object Plane Background Padding for Compensation Padded background Ref: Thomas Sikora Ref: Thomas Sikora Previous Frame Current Frame COMP9519 Multimedia Systems Lecture 5 Slide 47 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 48 J Zhang

13 One Typical Example -- Sprite Coding Scalability of Video Content Spatial Scalability Coder/Decoder 1. A non-changing background only has to be transmitted once. Only foreground objects transmitted and re- Inserted at the decoder 3. Object are much smaller than full video Coder/Decoder Coder/Decoder COMP9519 Multimedia Systems Lecture 5 Slide 49 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 50 J Zhang Scalability of Video Content Temporal Scalability 60 HZ Coder/Decoder 60 HZ Coder/Decoder 30 HZ Coder/Decoder 15 HZ The MPEG-4 Video Verification Model (VM) Coding of arbitrarily shaped images (VOP s) Coding of shape and Transparency information for each VOP I,P and B frames (VOP s) Block-based hybrid MC/DCT coding approach based on ITU H.63 and MPEG techniques Temporal and Spatial Scalability of VOP s COMP9519 Multimedia Systems Lecture 5 Slide 51 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 5 J Zhang

14 5.4 Introduction to H.64 Video Coding Standard It started from the ITU-T H.6L Project (Long term) It aims to improve the coding efficiency up to 50% compared to MPEG-4 video coding standard In Dec. 001, MPEG and ITU-T experts set up joint video team (JVT) to focus on this new standard. The final version of the standard has been approved by ITU-T 003. H.64 video coding standard or MPEG-4 Part 10. The new technical approaches: An Adaptive deblocking loop filter to remove the artifacts Multiple frame for ME/MC Predication in Intra mode Integer transform Optimized rate control strategy (my opinion) Video Codec Structure of H.64 MB of Input Image Signal - Intra/Inter Decoder 0 Coder Control Transform/ Quantizer Intra_Frame Prediction Comp. Predication Estimator Deq./Inv. Transform Deblocking Filter Control Quant. Transf. coeffs Entropy Coding Bitstream Output COMP9519 Multimedia Systems Lecture 5 Slide 53 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 54 J Zhang 5.4. Video Codec Structure of H.64 (H.6L TML-8 Design Part 1 of 4) Hybrid of DPCM/MC/Trans coding as in Prior standards. Common elements include: 16x16 macroblocks Conventional sampling of chrominance and association of luminance and chrominance data Block motion displacement vectors over picture boundaries Variable block-size motion Block transforms (not DCT, wavelets or fractals) Scalar quantization (weighted) H.64: Compensation Accuracy MB of Input Image Signal - Intra/Inter Decoder 0 Coder Control Transform/ Quantizer Intra_Frame Prediction Comp. Predication Deq./Inv. Transform Deblocking Filter Control Quant. Transf. coeffs Mode 1 0 Mode 0 1 Entropy Coding Mode Bitstream Output Mode Estimator Mode Mode Mode /4 (QCIF) or 1/8 (CIF) pel COMP9519 Multimedia Systems Lecture 5 Slide 55 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 56 J Zhang

15 5.4.4 H.64: Multiple Reference Frames MB of Input Image Signal - Intra/Inter Decoder 0 Coder Control Transform/ Quantizer Intra_Frame Prediction Comp. Predication Deq./Inv. Transform Deblocking Filter Control Quant. Transf. coeffs Entropy Coding Bitstream Output H.64: Multiple Reference Frames Compensation: Multiple reference pictures (per H.63++ Annex U) B picture prediction weighting New SP transition pictures for sequence switching Various block sizes and shapes for motion compensation (7 segmentations of the macroblock: 16x16, 16x8, 8x16, 8x8, 8x4, 4x8, 4x4) 1/4 sample (sort of per MPEG-4) and 1/8 sample accuracy motion Estimator Multiple Reference Frames for Compensation COMP9519 Multimedia Systems Lecture 5 Slide 57 J Zhang COMP9519 Multimedia Systems Lecture 5 Slide 58 J Zhang

### Video Compression Standards (II) A/Prof. Jian Zhang

Video Compression Standards (II) A/Prof. Jian Zhang NICTA & CSE UNSW COMP9519 Multimedia Systems S2 2009 jzhang@cse.unsw.edu.au Tutorial 2 : Image/video Coding Techniques Basic Transform coding Tutorial

### Lecture 4: Video Compression Standards (Part1) Tutorial 2 : Image/video Coding Techniques. Basic Transform coding Tutorial 2

Lecture 4: Video Compression Standards (Part1) Tutorial 2 : Image/video Coding Techniques Dr. Jian Zhang Conjoint Associate Professor NICTA & CSE UNSW COMP9519 Multimedia Systems S2 2006 jzhang@cse.unsw.edu.au

### Lecture 5: Error Resilience & Scalability

Lecture 5: Error Resilience & Scalability Dr Reji Mathew A/Prof. Jian Zhang NICTA & CSE UNSW COMP9519 Multimedia Systems S 010 jzhang@cse.unsw.edu.au Outline Error Resilience Scalability Including slides

### MPEG-4: Simple Profile (SP)

MPEG-4: Simple Profile (SP) I-VOP (Intra-coded rectangular VOP, progressive video format) P-VOP (Inter-coded rectangular VOP, progressive video format) Short Header mode (compatibility with H.263 codec)

### The Scope of Picture and Video Coding Standardization

H.120 H.261 Video Coding Standards MPEG-1 and MPEG-2/H.262 H.263 MPEG-4 H.264 / MPEG-4 AVC Thomas Wiegand: Digital Image Communication Video Coding Standards 1 The Scope of Picture and Video Coding Standardization

### Lecture 3: Image & Video Coding Techniques (II) & Standards (I) A/Prof. Jian Zhang

Lecture 3: Image & Video Coding Techniques (II) & Standards (I) A/Prof. Jian Zhang NICTA & CSE UNSW COMP9519 Multimedia Systems S2 2009 jzhang@cse.unsw.edu.au 3.1 Subband Coding The fundamental concept

### Interframe coding A video scene captured as a sequence of frames can be efficiently coded by estimating and compensating for motion between frames pri

MPEG MPEG video is broken up into a hierarchy of layer From the top level, the first layer is known as the video sequence layer, and is any self contained bitstream, for example a coded movie. The second

### Thanks for slides preparation of Dr. Shawmin Lei, Sharp Labs of America And, Mei-Yun Hsu February Material Sources

An Overview of MPEG4 Thanks for slides preparation of Dr. Shawmin Lei, Sharp Labs of America And, Mei-Yun Hsu February 1999 1 Material Sources The MPEG-4 Tutuorial, San Jose, March 1998 MPEG-4: Context

### Video Compression MPEG-4. Market s requirements for Video compression standard

Video Compression MPEG-4 Catania 10/04/2008 Arcangelo Bruna Market s requirements for Video compression standard Application s dependent Set Top Boxes (High bit rate) Digital Still Cameras (High / mid

### Digital Video Processing

Video signal is basically any sequence of time varying images. In a digital video, the picture information is digitized both spatially and temporally and the resultant pixel intensities are quantized.

### Outline Introduction MPEG-2 MPEG-4. Video Compression. Introduction to MPEG. Prof. Pratikgiri Goswami

to MPEG Prof. Pratikgiri Goswami Electronics & Communication Department, Shree Swami Atmanand Saraswati Institute of Technology, Surat. Outline of Topics 1 2 Coding 3 Video Object Representation Outline

### Laboratoire d'informatique, de Robotique et de Microélectronique de Montpellier Montpellier Cedex 5 France

Video Compression Zafar Javed SHAHID, Marc CHAUMONT and William PUECH Laboratoire LIRMM VOODDO project Laboratoire d'informatique, de Robotique et de Microélectronique de Montpellier LIRMM UMR 5506 Université

### H.264/AVC und MPEG-4 SVC - die nächsten Generationen der Videokompression

Fraunhofer Institut für Nachrichtentechnik Heinrich-Hertz-Institut Ralf Schäfer schaefer@hhi.de http://bs.hhi.de H.264/AVC und MPEG-4 SVC - die nächsten Generationen der Videokompression Introduction H.264/AVC:

### Chapter 11.3 MPEG-2. MPEG-2: For higher quality video at a bit-rate of more than 4 Mbps Defined seven profiles aimed at different applications:

Chapter 11.3 MPEG-2 MPEG-2: For higher quality video at a bit-rate of more than 4 Mbps Defined seven profiles aimed at different applications: Simple, Main, SNR scalable, Spatially scalable, High, 4:2:2,

### EE Multimedia Signal Processing. Scope & Features. Scope & Features. Multimedia Signal Compression VI (MPEG-4, 7)

EE799 -- Multimedia Signal Processing Multimedia Signal Compression VI (MPEG-4, 7) References: 1. http://www.mpeg.org 2. http://drogo.cselt.stet.it/mpeg/ 3. T. Berahimi and M.Kunt, Visual data compression

### Week 14. Video Compression. Ref: Fundamentals of Multimedia

Week 14 Video Compression Ref: Fundamentals of Multimedia Last lecture review Prediction from the previous frame is called forward prediction Prediction from the next frame is called forward prediction

### Video Coding Standards. Yao Wang Polytechnic University, Brooklyn, NY11201 http: //eeweb.poly.edu/~yao

Video Coding Standards Yao Wang Polytechnic University, Brooklyn, NY11201 http: //eeweb.poly.edu/~yao Outline Overview of Standards and Their Applications ITU-T Standards for Audio-Visual Communications

### Multimedia Standards

Multimedia Standards SS 2017 Lecture 5 Prof. Dr.-Ing. Karlheinz Brandenburg Karlheinz.Brandenburg@tu-ilmenau.de Contact: Dipl.-Inf. Thomas Köllmer thomas.koellmer@tu-ilmenau.de 1 Organisational issues

### Georgios Tziritas Computer Science Department

New Video Coding standards MPEG-4, HEVC Georgios Tziritas Computer Science Department http://www.csd.uoc.gr/~tziritas 1 MPEG-4 : introduction Motion Picture Expert Group Publication 1998 (Intern. Standardization

### Video Compression. Learning Objectives. Contents (Cont.) Contents. Dr. Y. H. Chan. Standards : Background & History

Video Compression Dr. Y. H. Chan Contents Fundamentals of video Picture formats Frame rates Temporal redundancy spatial redundancy compensation prediction estimation compensation vector Full search algorithm

### Video Coding Standards

Based on: Y. Wang, J. Ostermann, and Y.-Q. Zhang, Video Processing and Communications, Prentice Hall, 2002. Video Coding Standards Yao Wang Polytechnic University, Brooklyn, NY11201 http://eeweb.poly.edu/~yao

### Video Codecs. National Chiao Tung University Chun-Jen Tsai 1/5/2015

Video Codecs National Chiao Tung University Chun-Jen Tsai 1/5/2015 Video Systems A complete end-to-end video system: A/D color conversion encoder decoder color conversion D/A bitstream YC B C R format

### In the name of Allah. the compassionate, the merciful

In the name of Allah the compassionate, the merciful Digital Video Systems S. Kasaei Room: CE 315 Department of Computer Engineering Sharif University of Technology E-Mail: skasaei@sharif.edu Webpage:

### Video Compression An Introduction

Video Compression An Introduction The increasing demand to incorporate video data into telecommunications services, the corporate environment, the entertainment industry, and even at home has made digital

### Introduction to Video Coding

Introduction to Video Coding o Motivation & Fundamentals o Principles of Video Coding o Coding Standards Special Thanks to Hans L. Cycon from FHTW Berlin for providing first-hand knowledge and much of

### Introduction to Video Compression

Insight, Analysis, and Advice on Signal Processing Technology Introduction to Video Compression Jeff Bier Berkeley Design Technology, Inc. info@bdti.com http://www.bdti.com Outline Motivation and scope

### PREFACE...XIII ACKNOWLEDGEMENTS...XV

Contents PREFACE...XIII ACKNOWLEDGEMENTS...XV 1. MULTIMEDIA SYSTEMS...1 1.1 OVERVIEW OF MPEG-2 SYSTEMS...1 SYSTEMS AND SYNCHRONIZATION...1 TRANSPORT SYNCHRONIZATION...2 INTER-MEDIA SYNCHRONIZATION WITH

### CMPT 365 Multimedia Systems. Media Compression - Video Coding Standards

CMPT 365 Multimedia Systems Media Compression - Video Coding Standards Spring 2017 Edited from slides by Dr. Jiangchuan Liu CMPT365 Multimedia Systems 1 Video Coding Standards H.264/AVC CMPT365 Multimedia

### Welcome Back to Fundamentals of Multimedia (MR412) Fall, 2012 Chapter 10 ZHU Yongxin, Winson

Welcome Back to Fundamentals of Multimedia (MR412) Fall, 2012 Chapter 10 ZHU Yongxin, Winson zhuyongxin@sjtu.edu.cn Basic Video Compression Techniques Chapter 10 10.1 Introduction to Video Compression

### Standard Codecs. Image compression to advanced video coding. Mohammed Ghanbari. 3rd Edition. The Institution of Engineering and Technology

Standard Codecs Image compression to advanced video coding 3rd Edition Mohammed Ghanbari The Institution of Engineering and Technology Contents Preface to first edition Preface to second edition Preface

### Overview : Image/Video Coding Techniques

Overview : Image/Video Coding Techniques A/Prof. Jian Zhang NICTA & CSE UNSW COMP959 Multimedia Systems S 9 Pixel Representation Y,U,V Colour Space Colour can be represented by Red, Green and Blue components

### System Modeling and Implementation of MPEG-4. Encoder under Fine-Granular-Scalability Framework

System Modeling and Implementation of MPEG-4 Encoder under Fine-Granular-Scalability Framework Literature Survey Embedded Software Systems Prof. B. L. Evans by Wei Li and Zhenxun Xiao March 25, 2002 Abstract

### VIDEO AND IMAGE PROCESSING USING DSP AND PFGA. Chapter 3: Video Processing

ĐẠI HỌC QUỐC GIA TP.HỒ CHÍ MINH TRƯỜNG ĐẠI HỌC BÁCH KHOA KHOA ĐIỆN-ĐIỆN TỬ BỘ MÔN KỸ THUẬT ĐIỆN TỬ VIDEO AND IMAGE PROCESSING USING DSP AND PFGA Chapter 3: Video Processing 3.1 Video Formats 3.2 Video

### Video Coding Standards: H.261, H.263 and H.26L

5 Video Coding Standards: H.261, H.263 and H.26L Video Codec Design Iain E. G. Richardson Copyright q 2002 John Wiley & Sons, Ltd ISBNs: 0-471-48553-5 (Hardback); 0-470-84783-2 (Electronic) 5.1 INTRODUCTION

### TECHNICAL RESEARCH REPORT

TECHNICAL RESEARCH REPORT An Advanced Image Coding Algorithm that Utilizes Shape- Adaptive DCT for Providing Access to Content by R. Haridasan CSHCN T.R. 97-5 (ISR T.R. 97-16) The Center for Satellite

### VIDEO COMPRESSION STANDARDS

VIDEO COMPRESSION STANDARDS Family of standards: the evolution of the coding model state of the art (and implementation technology support): H.261: videoconference x64 (1988) MPEG-1: CD storage (up to

### 10.2 Video Compression with Motion Compensation 10.4 H H.263

Chapter 10 Basic Video Compression Techniques 10.11 Introduction to Video Compression 10.2 Video Compression with Motion Compensation 10.3 Search for Motion Vectors 10.4 H.261 10.5 H.263 10.6 Further Exploration

### Overview : Image/Video Coding Techniques

Overview : Image/Video Coding Techniques A/Prof. Jian Zhang NICTA & CSE UNSW Dr. Reji Mathew EE&T UNSW COMP959 Multimedia Systems S2 2 jzhang@cse.unsw.edu.au Pixel Representation Y,U,V Colour Space Colour

### Video coding. Concepts and notations.

TSBK06 video coding p.1/47 Video coding Concepts and notations. A video signal consists of a time sequence of images. Typical frame rates are 24, 25, 30, 50 and 60 images per seconds. Each image is either

### MPEG-2. ISO/IEC (or ITU-T H.262)

MPEG-2 1 MPEG-2 ISO/IEC 13818-2 (or ITU-T H.262) High quality encoding of interlaced video at 4-15 Mbps for digital video broadcast TV and digital storage media Applications Broadcast TV, Satellite TV,

### 4G WIRELESS VIDEO COMMUNICATIONS

4G WIRELESS VIDEO COMMUNICATIONS Haohong Wang Marvell Semiconductors, USA Lisimachos P. Kondi University of Ioannina, Greece Ajay Luthra Motorola, USA Song Ci University of Nebraska-Lincoln, USA WILEY

### DIGITAL TELEVISION 1. DIGITAL VIDEO FUNDAMENTALS

DIGITAL TELEVISION 1. DIGITAL VIDEO FUNDAMENTALS Television services in Europe currently broadcast video at a frame rate of 25 Hz. Each frame consists of two interlaced fields, giving a field rate of 50

### Advanced Video Coding: The new H.264 video compression standard

Advanced Video Coding: The new H.264 video compression standard August 2003 1. Introduction Video compression ( video coding ), the process of compressing moving images to save storage space and transmission

### Video Transcoding Architectures and Techniques: An Overview. IEEE Signal Processing Magazine March 2003 Present by Chen-hsiu Huang

Video Transcoding Architectures and Techniques: An Overview IEEE Signal Processing Magazine March 2003 Present by Chen-hsiu Huang Outline Background & Introduction Bit-rate Reduction Spatial Resolution

### New Techniques for Improved Video Coding

New Techniques for Improved Video Coding Thomas Wiegand Fraunhofer Institute for Telecommunications Heinrich Hertz Institute Berlin, Germany wiegand@hhi.de Outline Inter-frame Encoder Optimization Texture

### The Basics of Video Compression

The Basics of Video Compression Marko Slyz February 18, 2003 (Sourcecoders talk) 1/18 Outline 1. Non-technical Survey of Video Compressors 2. Basic Description of MPEG 1 3. Discussion of Other Compressors

### Lesson 6. MPEG Standards. MPEG - Moving Picture Experts Group Standards - MPEG-1 - MPEG-2 - MPEG-4 - MPEG-7 - MPEG-21

Lesson 6 MPEG Standards MPEG - Moving Picture Experts Group Standards - MPEG-1 - MPEG-2 - MPEG-4 - MPEG-7 - MPEG-21 What is MPEG MPEG: Moving Picture Experts Group - established in 1988 ISO/IEC JTC 1 /SC

### IEE 5037 Multimedia Communications Lecture 12: MPEG-4

IEE 5037 Multimedia Communications Lecture 12: MPEG-4 Adapted from Prof. Hang s slides Dept. Electronics Engineering, National Chiao Tung University MPEG-4 Video Coding Part 2: Object-oriented coding FGS

### JPEG 2000 vs. JPEG in MPEG Encoding

JPEG 2000 vs. JPEG in MPEG Encoding V.G. Ruiz, M.F. López, I. García and E.M.T. Hendrix Dept. Computer Architecture and Electronics University of Almería. 04120 Almería. Spain. E-mail: vruiz@ual.es, mflopez@ace.ual.es,

### The VC-1 and H.264 Video Compression Standards for Broadband Video Services

The VC-1 and H.264 Video Compression Standards for Broadband Video Services by Jae-Beom Lee Sarnoff Corporation USA Hari Kalva Florida Atlantic University USA 4y Sprin ger Contents PREFACE ACKNOWLEDGEMENTS

### IST MPEG-4 Video Compliant Framework

IST MPEG-4 Video Compliant Framework João Valentim, Paulo Nunes, Fernando Pereira Instituto de Telecomunicações, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisboa, Portugal Abstract This paper

### Multimedia Systems Video II (Video Coding) Mahdi Amiri April 2012 Sharif University of Technology

Course Presentation Multimedia Systems Video II (Video Coding) Mahdi Amiri April 2012 Sharif University of Technology Video Coding Correlation in Video Sequence Spatial correlation Similar pixels seem

### MPEG-4 departs from its predecessors in adopting a new object-based coding:

MPEG-4: a newer standard. Besides compression, pays great attention to issues about user interactivities. MPEG-4 departs from its predecessors in adopting a new object-based coding: Offering higher compression

### Upcoming Video Standards. Madhukar Budagavi, Ph.D. DSPS R&D Center, Dallas Texas Instruments Inc.

Upcoming Video Standards Madhukar Budagavi, Ph.D. DSPS R&D Center, Dallas Texas Instruments Inc. Outline Brief history of Video Coding standards Scalable Video Coding (SVC) standard Multiview Video Coding

### 2014 Summer School on MPEG/VCEG Video. Video Coding Concept

2014 Summer School on MPEG/VCEG Video 1 Video Coding Concept Outline 2 Introduction Capture and representation of digital video Fundamentals of video coding Summary Outline 3 Introduction Capture and representation

### LIST OF TABLES. Table 5.1 Specification of mapping of idx to cij for zig-zag scan 46. Table 5.2 Macroblock types 46

LIST OF TABLES TABLE Table 5.1 Specification of mapping of idx to cij for zig-zag scan 46 Table 5.2 Macroblock types 46 Table 5.3 Inverse Scaling Matrix values 48 Table 5.4 Specification of QPC as function

Lecture 11: Media Adaptation Scalable Coding, Dealing with Errors Some slides, images were from http://ip.hhi.de/imagecom_g1/savce/index.htm and John G. Apostolopoulos http://www.mit.edu/~6.344/spring2004

### Using animation to motivate motion

Using animation to motivate motion In computer generated animation, we take an object and mathematically render where it will be in the different frames Courtesy: Wikipedia Given the rendered frames (or

### ECE 634: Digital Video Systems Scalable coding: 3/23/17

ECE 634: Digital Video Systems Scalable coding: 3/23/17 Professor Amy Reibman MSEE 356 reibman@purdue.edu hip://engineering.purdue.edu/~reibman/ece634/index.html Scalability Outline IntroducNon: Heterogeneous

### Image and Video Watermarking

Telecommunications Seminar WS 1998 Data Hiding, Digital Watermarking and Secure Communications Image and Video Watermarking Herbert Buchner University of Erlangen-Nuremberg 16.12.1998 Outline 1. Introduction:

### Wavelet-Based Video Compression Using Long-Term Memory Motion-Compensated Prediction and Context-Based Adaptive Arithmetic Coding

Wavelet-Based Video Compression Using Long-Term Memory Motion-Compensated Prediction and Context-Based Adaptive Arithmetic Coding Detlev Marpe 1, Thomas Wiegand 1, and Hans L. Cycon 2 1 Image Processing

### 5LSE0 - Mod 10 Part 1. MPEG Motion Compensation and Video Coding. MPEG Video / Temporal Prediction (1)

1 Multimedia Video Coding & Architectures (5LSE), Module 1 MPEG-1/ Standards: Motioncompensated video coding 5LSE - Mod 1 Part 1 MPEG Motion Compensation and Video Coding Peter H.N. de With (p.h.n.de.with@tue.nl

### Lecture 3 Image and Video (MPEG) Coding

CS 598KN Advanced Multimedia Systems Design Lecture 3 Image and Video (MPEG) Coding Klara Nahrstedt Fall 2017 Overview JPEG Compression MPEG Basics MPEG-4 MPEG-7 JPEG COMPRESSION JPEG Compression 8x8 blocks

### Fernando Pereira. Instituto Superior Técnico

VIDEOTELEPHONY AND VIDEOCONFERENCE OVER ISDN Fernando Pereira Instituto Superior Técnico Digital Video Video versus Images Still Image Services No strong temporal requirements; no real-time notion. Video

### Chapter 10. Basic Video Compression Techniques Introduction to Video Compression 10.2 Video Compression with Motion Compensation

Chapter 10 Basic Video Compression Techniques 10.1 Introduction to Video Compression 10.2 Video Compression with Motion Compensation 10.3 Search for Motion Vectors 10.4 H.261 10.5 H.263 10.6 Further Exploration

### Video Coding in H.26L

Royal Institute of Technology MASTER OF SCIENCE THESIS Video Coding in H.26L by Kristofer Dovstam April 2000 Work done at Ericsson Radio Systems AB, Kista, Sweden, Ericsson Research, Department of Audio

### Module 6 STILL IMAGE COMPRESSION STANDARDS

Module 6 STILL IMAGE COMPRESSION STANDARDS Lesson 19 JPEG-2000 Error Resiliency Instructional Objectives At the end of this lesson, the students should be able to: 1. Name two different types of lossy

### ECE 417 Guest Lecture Video Compression in MPEG-1/2/4. Min-Hsuan Tsai Apr 02, 2013

ECE 417 Guest Lecture Video Compression in MPEG-1/2/4 Min-Hsuan Tsai Apr 2, 213 What is MPEG and its standards MPEG stands for Moving Picture Expert Group Develop standards for video/audio compression

### THE H.264 ADVANCED VIDEO COMPRESSION STANDARD

THE H.264 ADVANCED VIDEO COMPRESSION STANDARD Second Edition Iain E. Richardson Vcodex Limited, UK WILEY A John Wiley and Sons, Ltd., Publication About the Author Preface Glossary List of Figures List

### MPEG-2. And Scalability Support. Nimrod Peleg Update: July.2004

MPEG-2 And Scalability Support Nimrod Peleg Update: July.2004 MPEG-2 Target...Generic coding method of moving pictures and associated sound for...digital storage, TV broadcasting and communication... Dedicated

### Cross Layer Protocol Design

Cross Layer Protocol Design Radio Communication III The layered world of protocols Video Compression for Mobile Communication » Image formats» Pixel representation Overview» Still image compression Introduction»

### LECTURE VIII: BASIC VIDEO COMPRESSION TECHNIQUE DR. OUIEM BCHIR

1 LECTURE VIII: BASIC VIDEO COMPRESSION TECHNIQUE DR. OUIEM BCHIR 2 VIDEO COMPRESSION A video consists of a time-ordered sequence of frames, i.e., images. Trivial solution to video compression Predictive

### MPEG-4: Overview. Multimedia Naresuan University

MPEG-4: Overview Multimedia Naresuan University Sources - Chapters 1 and 2, The MPEG-4 Book, F. Pereira and T. Ebrahimi - Some slides are adapted from NTNU, Odd Inge Hillestad. MPEG-1 and MPEG-2 MPEG-1

### Ch. 4: Video Compression Multimedia Systems

Ch. 4: Video Compression Multimedia Systems Prof. Ben Lee (modified by Prof. Nguyen) Oregon State University School of Electrical Engineering and Computer Science 1 Outline Introduction MPEG Overview MPEG

### Parallel Implementation of Arbitrary-Shaped MPEG-4 Decoder for Multiprocessor Systems

Parallel Implementation of Arbitrary-Shaped MPEG-4 oder for Multiprocessor Systems Milan Pastrnak *,a,c, Peter H.N. de With a,c, Sander Stuijk c and Jef van Meerbergen b,c a LogicaCMG Nederland B.V., RTSE

### ITU-T DRAFT H.263 VIDEO CODING FOR LOW BITRATE COMMUNICATION LINE TRANSMISSION OF NON-TELEPHONE SIGNALS. DRAFT ITU-T Recommendation H.

INTERNATIONAL TELECOMMUNICATION UNION ITU-T DRAFT H.263 TELECOMMUNICATION (2 May, 1996) STANDARDIZATION SECTOR OF ITU LINE TRANSMISSION OF NON-TELEPHONE SIGNALS VIDEO CODING FOR LOW BITRATE COMMUNICATION

### CMPT 365 Multimedia Systems. Media Compression - Video

CMPT 365 Multimedia Systems Media Compression - Video Spring 2017 Edited from slides by Dr. Jiangchuan Liu CMPT365 Multimedia Systems 1 Introduction What s video? a time-ordered sequence of frames, i.e.,

### Introduction of Video Codec

Introduction of Video Codec Min-Chun Hu anita_hu@mail.ncku.edu.tw MISLab, R65601, CSIE New Building 3D Augmented Reality and Interactive Sensor Technology, 2015 Fall The Need for Video Compression High-Definition

### Lecture 6: Compression II. This Week s Schedule

Lecture 6: Compression II Reading: book chapter 8, Section 1, 2, 3, 4 Monday This Week s Schedule The concept behind compression Rate distortion theory Image compression via DCT Today Speech compression

### MULTIDIMENSIONAL SIGNAL, IMAGE, AND VIDEO PROCESSING AND CODING

MULTIDIMENSIONAL SIGNAL, IMAGE, AND VIDEO PROCESSING AND CODING JOHN W. WOODS Rensselaer Polytechnic Institute Troy, New York»iBllfllfiii.. i. ELSEVIER AMSTERDAM BOSTON HEIDELBERG LONDON NEW YORK OXFORD

### 微电子学院 School of Microelectronics. Welcome Back to Fundamentals of Multimedia (MR412) Fall, 2012 Chapter 12 ZHU Yongxin, Winson

Welcome Back to Fundamentals of Multimedia (MR412) Fall, 2012 Chapter 12 ZHU Yongxin, Winson zhuyongxin@sjtu.edu.cn Chapter 12 MPEG Video Coding II - MPEG-4, 7 and Beyond 12.1 Overview of MPEG-4 12.2 Object-based

### Lecture 13 Video Coding H.264 / MPEG4 AVC

Lecture 13 Video Coding H.264 / MPEG4 AVC Last time we saw the macro block partition of H.264, the integer DCT transform, and the cascade using the DC coefficients with the WHT. H.264 has more interesting

### Lecture 1: Introduction & Image and Video Coding Techniques (I)

Lecture 1: Introduction & Image and Video Coding Techniques (I) A/Prof. Jian Zhang NICTA & CSE UNSW COMP9519 Multimedia Systems S 009 jzhang@cse.unsw.edu.au 1.1 Introduction Our team s profile Multimedia

### Optimal Estimation for Error Concealment in Scalable Video Coding

Optimal Estimation for Error Concealment in Scalable Video Coding Rui Zhang, Shankar L. Regunathan and Kenneth Rose Department of Electrical and Computer Engineering University of California Santa Barbara,

### A Hybrid Temporal-SNR Fine-Granular Scalability for Internet Video

318 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY, VOL. 11, NO. 3, MARCH 2001 A Hybrid Temporal-SNR Fine-Granular Scalability for Internet Video Mihaela van der Schaar, Member, IEEE, and

### Review and Implementation of DWT based Scalable Video Coding with Scalable Motion Coding.

Project Title: Review and Implementation of DWT based Scalable Video Coding with Scalable Motion Coding. Midterm Report CS 584 Multimedia Communications Submitted by: Syed Jawwad Bukhari 2004-03-0028 About

### Emerging H.26L Standard:

Emerging H.26L Standard: Overview and TMS320C64x Digital Media Platform Implementation White Paper UB Video Inc. Suite 400, 1788 west 5 th Avenue Vancouver, British Columbia, Canada V6J 1P2 Tel: 604-737-2426;

### Motion Estimation. Original. enhancement layers. Motion Compensation. Baselayer. Scan-Specific Entropy Coding. Prediction Error.

ON VIDEO SNR SCALABILITY Lisimachos P. Kondi, Faisal Ishtiaq and Aggelos K. Katsaggelos Northwestern University Dept. of Electrical and Computer Engineering 2145 Sheridan Road Evanston, IL 60208 E-Mail:

### Digital video coding systems MPEG-1/2 Video

Digital video coding systems MPEG-1/2 Video Introduction What is MPEG? Moving Picture Experts Group Standard body for delivery of video and audio. Part of ISO/IEC/JTC1/SC29/WG11 150 companies & research

### System Modeling and Implementation of MPEG-4. Encoder under Fine-Granular-Scalability Framework

System Modeling and Implementation of MPEG-4 Encoder under Fine-Granular-Scalability Framework Final Report Embedded Software Systems Prof. B. L. Evans by Wei Li and Zhenxun Xiao May 8, 2002 Abstract Stream

### The new Hybrid approach to protect MPEG-2 video header

The new Hybrid approach to protect MPEG-2 video header *YUK YING CHUNG, *XIANG ZHANG, *XIAOMING CHEN, *MOHD AFIZI MOHD SHUKRAN, **CHANGSEOK BAE *School of Information Technologies, University of Sydney,

### Compressed-Domain Video Processing and Transcoding

Compressed-Domain Video Processing and Transcoding Susie Wee, John Apostolopoulos Mobile & Media Systems Lab HP Labs Stanford EE392J Lecture 2006 Hewlett-Packard Development Company, L.P. The information

### IMAGE COMPRESSION. Image Compression. Why? Reducing transportation times Reducing file size. A two way event - compression and decompression

IMAGE COMPRESSION Image Compression Why? Reducing transportation times Reducing file size A two way event - compression and decompression 1 Compression categories Compression = Image coding Still-image

### INTERNATIONAL TELECOMMUNICATION UNION ITU-T H.263 (03/96) TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU TRANSMISSION OF NON-TELEPHONE SIGNALS VIDEO

INTERNATIONAL TELECOMMUNICATION UNION ITU-T H. TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU TRANSMISSION OF NON-TELEPHONE SIGNALS VIDEO CODING FOR LOW BIT RATE COMMUNICATION ITU-T (Previously CCITT

### Digital Video Compression and H.261 Recommendation

Digital Video Compression and H.261 Recommendation Fernando Pereira Klagenfurt, Austria, October 2008 Video versus Images Still Image Services No strong temporal requirements; no realtime notion. Video

### MULTIMEDIA COMMUNICATION

MULTIMEDIA COMMUNICATION Laboratory Session: JPEG Standard Fernando Pereira The objective of this lab session about the JPEG (Joint Photographic Experts Group) standard is to get the students familiar

### Introduction to Video Encoding

Introduction to Video Encoding INF5063 23. September 2011 History of MPEG Motion Picture Experts Group MPEG1 work started in 1988, published by ISO in 1993 Part 1 Systems, Part 2 Video, Part 3 Audio, Part

### Introduction to LAN/WAN. Application Layer 4

Introduction to LAN/WAN Application Layer 4 Multimedia Multimedia: Audio + video Human ear: 20Hz 20kHz, Dogs hear higher freqs DAC converts audio waves to digital E.g PCM uses 8-bit samples 8000 times