CSCD 443/533 Advanced Networks Fall 2017

Size: px
Start display at page:

Download "CSCD 443/533 Advanced Networks Fall 2017"

Transcription

1 CSCD 443/533 Advanced Networks Fall 2017 Lecture 18 Compression of Video and Audio 1

2 Topics Compression technology Motivation Human attributes make it possible Audio Compression Video Compression Performance 2

3 Motivation, Why Compress? Why do we need to compress streaming media? Look at one instance 640 X 480 pixel frames 24 bits color/pixel 30 frames / sec No compression, takes over 200 Mbps to transmit just video Do you have a 200 Mbps link? We need massive compression to be able to view streaming video and audio with our current network

4 Motivation, Why Compress? What does compression buy us? Lossless DVD video Mbps Compressed DVD video - 4 Mbps 50:1 compression ratio!

5 Why Compress? In a Nutshell To reduce the file size To deliver stream to the user To conserve storage space Choosing a compression rate is a balance: Quality of Available the Media bandwidth

6 So, Why Compress? Delivering video over Web means compromises Mostly trading image quality for lower bit rates In general, Video and audio are compressed Stuffed into a container and Delivered to you via web If done well, you won't notice The missing bits and The delivery of media Discuss individual format, codecs and tradeoffs

7 Definitions File Format Particular way information is stored in a file Known as containers for streaming media Codec Codec is an acronym for Compression/Decompression Codec is any technology for compressing and decompressing data. Compression Reduces file size by removing audio or video information Takes advantage of human perception

8 Format vs. Codec Example Flash Video (FLV) is a file format H.264, On2, VP6, Sorenson Spark are codecs for the flash video file

9 Container File Formats Purpose of container formats Examples Function as "black boxes" for holding a variety of media formats Good container formats can handle files compressed with a variety of different codecs In a perfect world, you could put any codec in any container format Unfortunately are some incompatibilities MPEG-2, Advanced Systems Format (ASF) from Microsoft, AVI, Quicktime (MOV), MP4, Flash (FLV) RealMedia

10 Multimedia Container Files Multimedia file extensions.mov,.ogg,.wmv,.flv,.mp4,.mpeg Essentially, videos packaged Into encapsulation containers, or wrapper formats, that contain all information needed to present video You can think of file formats as being containers that hold all this information Very similar to a.zip,.sit or.rar file

11 Differences in Containers Why are certain formats are popular? Popular Support File Size How widely supported is the format? Larger is not better for streaming files Support for advanced codec functionality Older formats such as AVI do not support new codec features like B-frames or VBR audio Support for advanced content Such as chapters, subtitles, meta-tags, userdata.

12 Compression

13 Compression Two Types: Lossless Lossy Keeps All Bits Removes Bits

14 Lossy Compression Lossy compression schemes reduce file size by discarding some amount of data during encoding before sent over Internet Once received by client, codec attempts to reconstruct information that was lost or discarded

15 Video Lossy Compression Image Compression Image format uses lossy compression to sample an image and discard unnecessary color/contrast information

16 Can you really see difference?

17 Video Lossy Compression Why can you do lossy compression? Spatial and temporal redundancy Pixel values are not independent, correlated with their neighbors both within same frame and across frame Value of pixel is predictable given values of neighboring pixels Psychovisual redundancy Human eye has limited response to fine spatial detail, Less sensitive to detail near object edges or around shotchanges Impairments introduced by bit rate reduction should not be visible to human viewer

18 Audio Lossy Compression Audio compression Lossy discards frequencies on high and low end of spectrum and attempts to locate and remove unnecessary audio data More on this Nice description and example programs

19 Audio Streaming Formats Many formats and standards for streaming audio RealNetworks' RealAudio, streaming MP3, Macromedia's Flash and Director Shockwave, Microsoft's Windows Media, and Apple's QuickTime Also recognized standard formats, including Liquid Audio, MP3, MIDI, WAV, and AU

20 Audio Lossy Compression First, player decompresses audio file as it downloads to your computer Then fills in missing information according to the instructions set by codec Compressed file is unintelligible to listener Decompressed file is intelligible but of a lower quality than original

21 MP3 Audio Lossy Compression Example - MP3 MP3 lossy audio data compression algorithm takes advantage of perceptual limitation of human hearing Auditory Masking Discovered (in late 1800's) that tone could be rendered inaudible by another tone of lower frequency How your brain perceives similar sounds

22 MP3 Audio Lossy Compression Uncompressed audio, Like CDs, stores more data than your brain can actually process For example, Two notes are very similar and very close together, your brain may perceive only one of them Two sounds are different, one is much louder than the other, your brain may never perceive the quieter signal

23 MP3 Audio Lossy Compression Study these auditory phenomena Psychoacoustics, Can be accurately described in tables and charts, Mathematical models representing human hearing patterns These can be stored in the codec as reference tables Article on psychoacoustics

24 MP3 Audio Lossy Compression MP3 Encoding Tools Analyze incoming source signal, Break it down into mathematical patterns, and Compare these patterns to psychoacoustic models stored in encoder itself Encoder can then discard most of data that doesn't match stored models, keeping that which does Shrinks file by discarding great deal of extra data

25 MP3 Audio Lossy Compression MP3 encoding process two-pass system Step 1 Run all psychoacoustic models, discarding data Then compress what's left to shrink storage space Step 2 Huffman coding, does not discard any data Lets you store what's left in a smaller amount of space Uses fewer bits to store most common symbols Steps 2a - Break resulting audio stream into frames assembled into a bitstream, with header information preceding each data frame Headers contain "meta-data" specific to that frame Such as an ID, bitrate, audio frequency, padding, type of frame, MPEG1 or 2

26 Basic Structure of Audio Encoder Limit values to audible tones Note: A decoder works in just the opposite manner

27 Processes of and Audio Encoder Mapping Block divides audio inputs into 32 equalwidth frequency subbands (samples) Psychoacoustic Block calculates masking threshold for each subband

28 Processes of and Audio Encoder Bit-Allocation Block (in Quantizer block) allocates bits using outputs of the Mapping and Psychoacoustic blocks Quantizer & Coding Block scales and quantize (reduce) the samples Frame Packing Block formats the headers into an encoded stream samples with

29 Video Encoding, Standards

30 MPEG Organization Moving Picture Experts Group Established in 1988 Standards under International Organization for standardization (ISO) and International Electro technical Commission (IEC) Official name: ISO/IEC JTC1 SC29 WG11 Responsible for MPEG standards

31 Evolution of MPEG MPEG-1 Initial audio/video compression standard Used by VCD s 1990's MP3 = MPEG-1 audio layer 3 Target of 1.5 Mb/s bitrate at 352x240 resolution Only supports progressive pictures, no interlaced pictures

32 Evolution of MPEG MPEG-2 Standard, still widely used in DVD and Digital TV Support in current hardware implies that it will be here for a long time Transition to HDTV has taken over 10 years and is not finished yet Different profiles and levels allow for quality control

33 Evolution of MPEG MPEG-3 Originally developed for HDTV, but abandoned when MPEG-2 was determined to be sufficient MPEG-4 Includes support for AV objects, 3D content, low bitrate encoding, and DRM In practice, provides equal quality to MPEG-2 at a lower bitrate MPEG-4 Part 10 is H.264, which is used in HD- DVD and Blu-Ray H.264 is the encoding used in video

34 MPEG technical specification Part 1 - Systems - describes synchronization and multiplexing of video and audio. Part 2 - Video - compression codec for interlaced and noninterlaced video signals. Part 3 - Audio - compression codec for perceptual coding of audio signals. A multichannel-enabled extension of MPEG-1 audio. Part 4 - Describes procedures for testing compliance. Part 5 - Describes systems for Software simulation. Part 6 - Describes extensions for DSM-CC (Digital Storage Media Command and Control.) Part 7 - Advanced Audio Coding (AAC) Part 8 - Deleted Part 9 - Extension for real time interfaces. Part 10 - Conformance extensions for DSM-CC.

35 MPEG Video spatial domain processing Spatial Domain Handled Similarly to JPEG Convert RGB values to YUV colorspace One Brightness and two other color representations RGB from Television, YUV graphics processing Y represents luminosity, U,V color Can represent YUV with fewer bits since human eye can't tell if color is missing We care more about brightness Split frame into 8x8 blocks

36 8 x 8 Blocks

37 MPEG Video spatial domain processing 2-D Discrete Cosine Transform (DCT) on each block Similar to a Fourier Transform for Signal Processing Transforms blocks into higher frequency and lower frequency values Pushes more important least frequent values to upper quadrant of the 8 X 8 block For typical image, most of visually significant information about image is concentrated in just a few coefficients of DCT Quantization of DCT coefficients Values that are near zero, converted to zero Values that are smaller, shrunk All are represented by integers

38 Quantization matrix matrix divides each coefficient by a number. The quantization matrix is pre-calculated and defined by the JPEG standard and favors the items in the top left corner of the matrix, the more frequency significant terms. Each coefficient has a different weighting

39 Run-length Encoding The regular JPEG standard uses an advanced version of Huffman coding

40 DCT Transform on Blocks Final Result Reduction in Number of Bits De-compression is the reverse process However, the lossy part of this, can't quite get back to the original image there is a loss of information Nice Examples using Discrete Cosine Transform

41 MPEG video time domain processing Totally new ballgame (this concept doesn t exist in JPEG) General idea Use motion vectors to specify how a 16x16 macroblock translates between reference frames and current frame, then code difference between reference and actual block

42 MPEG video time domain processing GOP (Group of Pictures) GOP is a set of consecutive frames that can be decoded without any other reference frames Usually 12 or 15 frames Starts with I frame

43 MPEG video time domain processing Group of Pictures (GOP) I-frames Can be reconstructed without any reference to other frames, like still pictures P-frames Forward predicted from last I-frame and P-frames, Code differences like movement Two to 4 frames in the future B-frames Forward and backward predicted

44 MPEG Processing GOP

45 MPEG GOP

46 Final Comments on Prediction Only use motion vector if a close match can be found Evaluate closeness with Mean Standard Error or other metric Can t search all possible blocks, so need a smart algorithm If no suitable match found, just code the macroblock as an I-block If a scene change is detected, start fresh Don t want too many P or B frames in a row Predictive error will keep propagating until next I frame Delay in decoding

47 MPEG Usefulness Multimedia Communications Webcasting Broadcasting Video on Demand Interactive Digital Media Telecommunications Mobile communications

48 References Overviews of Codecs and Container Formats _containers.html?page=2 Ripping CD's and Encoding audio building-your-library/ Mp3 Audio Audio Streaming

49 Summary Video and audio has become a huge part of our daily interaction with the Internet New codecs and file formats being proposed all the time Number of devices with different needs driving the push for more efficient ways to compress and deliver streaming media

50 End New program is up last assignment

51 1

52

53

54 Motivation, Why Compress? What does compression buy us? Lossless DVD video Mbps Compressed DVD video - 4 Mbps 50:1 compression ratio! 4

55 Why Compress? In a Nutshell To reduce the file size To deliver stream to the user To conserve storage space Choosing a compression rate is a balance: Quality of Available the Media bandwidth 5

56 So, Why Compress? Delivering video over Web means compromises Mostly trading image quality for lower bit rates In general, Video and audio are compressed Stuffed into a container and Delivered to you via web If done well, you won't notice The missing bits and The delivery of media Discuss individual format, codecs and tradeoffs 6

57

58

59 Container File Formats Purpose of container formats Examples Function as "black boxes" for holding a variety of media formats Good container formats can handle files compressed with a variety of different codecs In a perfect world, you could put any codec in any container format Unfortunately are some incompatibilities MPEG-2, Advanced Systems Format (ASF) from Microsoft, AVI, Quicktime (MOV), MP4, Flash (FLV) RealMedia 9

60 Multimedia Container Files Multimedia file extensions.mov,.ogg,.wmv,.flv,.mp4,.mpeg Essentially, videos packaged Into encapsulation containers, or wrapper formats, that contain all information needed to present video You can think of file formats as being containers that hold all this information Very similar to a.zip,.sit or.rar file 10

61 Differences in Containers Why are certain formats are popular? Popular Support How widely supported is the format? File Size Larger is not better for streaming files Support for advanced codec functionality Older formats such as AVI do not support new codec features like B-frames or VBR audio Support for advanced content Such as chapters, subtitles, meta-tags, userdata. 11

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77 Mapping-divide into 32 subbands, or frequency samples Psychoacoustic- below which noise is imperceptible to the human ear (Map & Psycho can be done independently Bit-Allocation-total noise to mask ratios can be minimized, over all the channels and subbands Frame Packing header includes bit allocation and scaling information (scale factor) Quantizer & Coding scaled and quantized according to the bit allocation 27

78 Mapping-divide into 32 subbands, or frequency samples Psychoacoustic- below which noise is imperceptible to the human ear (Map & Psycho can be done independently Bit-Allocation-total noise to mask ratios can be minimized, over all the channels and subbands Frame Packing header includes bit allocation and scaling information (scale factor) Quantizer & Coding scaled and quantized according to the bit allocation 28

79

80

81

82

83

84

85

86 8 x 8 Blocks 36

87

88 Quantization matrix matrix divides each coefficient by a number. The quantization matrix is pre-calculated and defined by the JPEG standard and favors the items in the top left corner of the matrix, the more frequency significant terms. Each coefficient has a different weighting Click to add an outline 38

89 Run-length Encoding The regular JPEG standard uses an advanced version of Huffman coding 39

90 40

91

92

93 The MPEG file consists of compressed video data, called the video stream. The basic unit of the video stream is a "Group of Pictures" (GOP), made up of three picture types, also called frames: I, P, and B. The I -frames can be restructured without any references to other frames. On average, the I -frames can occur one in every ten-fifteen frames of motion picture. This type of frames contains information only about itself. P -frames can only be recreated by references from previous I-frame or P-frame; it is impossible to construct them without any data of another frame. The B -frames are referred to as bi-directional frames, because they can be recreated based on forward and backward predictions from the information presented in the nearest preceding and following I or P frame. 43

94

95

96

97

98

99 Summary Video and audio has become a huge part of our daily interaction with the Internet New codecs and file formats being proposed all the time Number of devices with different needs driving the push for more efficient ways to compress and deliver streaming media 49

100

CISC 7610 Lecture 3 Multimedia data and data formats

CISC 7610 Lecture 3 Multimedia data and data formats CISC 7610 Lecture 3 Multimedia data and data formats Topics: Perceptual limits of multimedia data JPEG encoding of images MPEG encoding of audio MPEG and H.264 encoding of video Multimedia data: Perceptual

More information

Compression; Error detection & correction

Compression; Error detection & correction Compression; Error detection & correction compression: squeeze out redundancy to use less memory or use less network bandwidth encode the same information in fewer bits some bits carry no information some

More information

Image and video processing

Image and video processing Image and video processing Digital video Dr. Pengwei Hao Agenda Digital video Video compression Video formats and codecs MPEG Other codecs Web video - 2 - Digital Video Until the arrival of the Pentium

More information

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 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

More information

Perceptual coding. A psychoacoustic model is used to identify those signals that are influenced by both these effects.

Perceptual coding. A psychoacoustic model is used to identify those signals that are influenced by both these effects. Perceptual coding Both LPC and CELP are used primarily for telephony applications and hence the compression of a speech signal. Perceptual encoders, however, have been designed for the compression of general

More information

Lecture 16 Perceptual Audio Coding

Lecture 16 Perceptual Audio Coding EECS 225D Audio Signal Processing in Humans and Machines Lecture 16 Perceptual Audio Coding 2012-3-14 Professor Nelson Morgan today s lecture by John Lazzaro www.icsi.berkeley.edu/eecs225d/spr12/ Hero

More information

DigiPoints Volume 1. Student Workbook. Module 8 Digital Compression

DigiPoints Volume 1. Student Workbook. Module 8 Digital Compression Digital Compression Page 8.1 DigiPoints Volume 1 Module 8 Digital Compression Summary This module describes the techniques by which digital signals are compressed in order to make it possible to carry

More information

Both LPC and CELP are used primarily for telephony applications and hence the compression of a speech signal.

Both LPC and CELP are used primarily for telephony applications and hence the compression of a speech signal. Perceptual coding Both LPC and CELP are used primarily for telephony applications and hence the compression of a speech signal. Perceptual encoders, however, have been designed for the compression of general

More information

Compression Part 2 Lossy Image Compression (JPEG) Norm Zeck

Compression Part 2 Lossy Image Compression (JPEG) Norm Zeck Compression Part 2 Lossy Image Compression (JPEG) General Compression Design Elements 2 Application Application Model Encoder Model Decoder Compression Decompression Models observe that the sensors (image

More information

Audio and video compression

Audio and video compression Audio and video compression 4.1 introduction Unlike text and images, both audio and most video signals are continuously varying analog signals. Compression algorithms associated with digitized audio and

More information

Audio-coding standards

Audio-coding standards Audio-coding standards The goal is to provide CD-quality audio over telecommunications networks. Almost all CD audio coders are based on the so-called psychoacoustic model of the human auditory system.

More information

Perceptual Coding. Lossless vs. lossy compression Perceptual models Selecting info to eliminate Quantization and entropy encoding

Perceptual Coding. Lossless vs. lossy compression Perceptual models Selecting info to eliminate Quantization and entropy encoding Perceptual Coding Lossless vs. lossy compression Perceptual models Selecting info to eliminate Quantization and entropy encoding Part II wrap up 6.082 Fall 2006 Perceptual Coding, Slide 1 Lossless vs.

More information

ELL 788 Computational Perception & Cognition July November 2015

ELL 788 Computational Perception & Cognition July November 2015 ELL 788 Computational Perception & Cognition July November 2015 Module 11 Audio Engineering: Perceptual coding Coding and decoding Signal (analog) Encoder Code (Digital) Code (Digital) Decoder Signal (analog)

More information

Index. 1. Motivation 2. Background 3. JPEG Compression The Discrete Cosine Transformation Quantization Coding 4. MPEG 5.

Index. 1. Motivation 2. Background 3. JPEG Compression The Discrete Cosine Transformation Quantization Coding 4. MPEG 5. Index 1. Motivation 2. Background 3. JPEG Compression The Discrete Cosine Transformation Quantization Coding 4. MPEG 5. Literature Lossy Compression Motivation To meet a given target bit-rate for storage

More information

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

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

More information

About MPEG Compression. More About Long-GOP Video

About MPEG Compression. More About Long-GOP Video About MPEG Compression HD video requires significantly more data than SD video. A single HD video frame can require up to six times more data than an SD frame. To record such large images with such a low

More information

Compression; Error detection & correction

Compression; Error detection & correction Compression; Error detection & correction compression: squeeze out redundancy to use less memory or use less network bandwidth encode the same information in fewer bits some bits carry no information some

More information

DIGITAL TELEVISION 1. DIGITAL VIDEO FUNDAMENTALS

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

More information

Video Compression An Introduction

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

More information

Audio-coding standards

Audio-coding standards Audio-coding standards The goal is to provide CD-quality audio over telecommunications networks. Almost all CD audio coders are based on the so-called psychoacoustic model of the human auditory system.

More information

Professor Laurence S. Dooley. School of Computing and Communications Milton Keynes, UK

Professor Laurence S. Dooley. School of Computing and Communications Milton Keynes, UK Professor Laurence S. Dooley School of Computing and Communications Milton Keynes, UK How many bits required? 2.4Mbytes 84Kbytes 9.8Kbytes 50Kbytes Data Information Data and information are NOT the same!

More information

Compression and File Formats

Compression and File Formats Compression and File Formats 1 Compressing Moving Images Methods: Motion JPEG, Cinepak, Indeo, MPEG Known as CODECs compression / decompression algorithms hardware and software implementations symmetrical

More information

5: Music Compression. Music Coding. Mark Handley

5: Music Compression. Music Coding. Mark Handley 5: Music Compression Mark Handley Music Coding LPC-based codecs model the sound source to achieve good compression. Works well for voice. Terrible for music. What if you can t model the source? Model the

More information

Mpeg 1 layer 3 (mp3) general overview

Mpeg 1 layer 3 (mp3) general overview Mpeg 1 layer 3 (mp3) general overview 1 Digital Audio! CD Audio:! 16 bit encoding! 2 Channels (Stereo)! 44.1 khz sampling rate 2 * 44.1 khz * 16 bits = 1.41 Mb/s + Overhead (synchronization, error correction,

More information

Multimedia Systems Image III (Image Compression, JPEG) Mahdi Amiri April 2011 Sharif University of Technology

Multimedia Systems Image III (Image Compression, JPEG) Mahdi Amiri April 2011 Sharif University of Technology Course Presentation Multimedia Systems Image III (Image Compression, JPEG) Mahdi Amiri April 2011 Sharif University of Technology Image Compression Basics Large amount of data in digital images File size

More information

Networking Applications

Networking Applications Networking Dr. Ayman A. Abdel-Hamid College of Computing and Information Technology Arab Academy for Science & Technology and Maritime Transport Multimedia Multimedia 1 Outline Audio and Video Services

More information

15 Data Compression 2014/9/21. Objectives After studying this chapter, the student should be able to: 15-1 LOSSLESS COMPRESSION

15 Data Compression 2014/9/21. Objectives After studying this chapter, the student should be able to: 15-1 LOSSLESS COMPRESSION 15 Data Compression Data compression implies sending or storing a smaller number of bits. Although many methods are used for this purpose, in general these methods can be divided into two broad categories:

More information

Principles of Audio Coding

Principles of Audio Coding Principles of Audio Coding Topics today Introduction VOCODERS Psychoacoustics Equal-Loudness Curve Frequency Masking Temporal Masking (CSIT 410) 2 Introduction Speech compression algorithm focuses on exploiting

More information

What is multimedia? Multimedia. Continuous media. Most common media types. Continuous media processing. Interactivity. What is multimedia?

What is multimedia? Multimedia. Continuous media. Most common media types. Continuous media processing. Interactivity. What is multimedia? Multimedia What is multimedia? Media types +Text + Graphics + Audio +Image +Video Interchange formats What is multimedia? Multimedia = many media User interaction = interactivity Script = time 1 2 Most

More information

MULTIMEDIA SYSTEMS

MULTIMEDIA SYSTEMS 1 Department of Computer Engineering, Faculty of Engineering King Mongkut s Institute of Technology Ladkrabang 01076531 MULTIMEDIA SYSTEMS Pk Pakorn Watanachaturaporn, Wt ht Ph.D. PhD pakorn@live.kmitl.ac.th,

More information

UNDERSTANDING MUSIC & VIDEO FORMATS

UNDERSTANDING MUSIC & VIDEO FORMATS ComputerFixed.co.uk Page: 1 Email: info@computerfixed.co.uk UNDERSTANDING MUSIC & VIDEO FORMATS Are you confused with all the different music and video formats available? Do you know the difference between

More information

Chapter 14 MPEG Audio Compression

Chapter 14 MPEG Audio Compression Chapter 14 MPEG Audio Compression 14.1 Psychoacoustics 14.2 MPEG Audio 14.3 Other Commercial Audio Codecs 14.4 The Future: MPEG-7 and MPEG-21 14.5 Further Exploration 1 Li & Drew c Prentice Hall 2003 14.1

More information

Multimedia. What is multimedia? Media types. Interchange formats. + Text +Graphics +Audio +Image +Video. Petri Vuorimaa 1

Multimedia. What is multimedia? Media types. Interchange formats. + Text +Graphics +Audio +Image +Video. Petri Vuorimaa 1 Multimedia What is multimedia? Media types + Text +Graphics +Audio +Image +Video Interchange formats Petri Vuorimaa 1 What is multimedia? Multimedia = many media User interaction = interactivity Script

More information

Figure 1. Generic Encoder. Window. Spectral Analysis. Psychoacoustic Model. Quantize. Pack Data into Frames. Additional Coding.

Figure 1. Generic Encoder. Window. Spectral Analysis. Psychoacoustic Model. Quantize. Pack Data into Frames. Additional Coding. Introduction to Digital Audio Compression B. Cavagnolo and J. Bier Berkeley Design Technology, Inc. 2107 Dwight Way, Second Floor Berkeley, CA 94704 (510) 665-1600 info@bdti.com http://www.bdti.com INTRODUCTION

More information

Bluray (

Bluray ( Bluray (http://www.blu-ray.com/faq) MPEG-2 - enhanced for HD, also used for playback of DVDs and HDTV recordings MPEG-4 AVC - part of the MPEG-4 standard also known as H.264 (High Profile and Main Profile)

More information

Computing in the Modern World

Computing in the Modern World Computing in the Modern World BCS-CMW-7: Data Representation Wayne Summers Marion County October 25, 2011 There are 10 kinds of people in the world: those who understand binary and those who don t. Pre-exercises

More information

Part 1 of 4. MARCH

Part 1 of 4. MARCH Presented by Brought to You by Part 1 of 4 MARCH 2004 www.securitysales.com A1 Part1of 4 Essentials of DIGITAL VIDEO COMPRESSION By Bob Wimmer Video Security Consultants cctvbob@aol.com AT A GLANCE Compression

More information

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

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

More information

Lossy compression. CSCI 470: Web Science Keith Vertanen

Lossy compression. CSCI 470: Web Science Keith Vertanen Lossy compression CSCI 470: Web Science Keith Vertanen Digital audio Overview Sampling rate Quan5za5on MPEG audio layer 3 (MP3) JPEG s5ll images Color space conversion, downsampling Discrete Cosine Transform

More information

Image, video and audio coding concepts. Roadmap. Rationale. Stefan Alfredsson. (based on material by Johan Garcia)

Image, video and audio coding concepts. Roadmap. Rationale. Stefan Alfredsson. (based on material by Johan Garcia) Image, video and audio coding concepts Stefan Alfredsson (based on material by Johan Garcia) Roadmap XML Data structuring Loss-less compression (huffman, LZ77,...) Lossy compression Rationale Compression

More information

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

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

More information

Audio Compression. Audio Compression. Absolute Threshold. CD quality audio:

Audio Compression. Audio Compression. Absolute Threshold. CD quality audio: Audio Compression Audio Compression CD quality audio: Sampling rate = 44 KHz, Quantization = 16 bits/sample Bit-rate = ~700 Kb/s (1.41 Mb/s if 2 channel stereo) Telephone-quality speech Sampling rate =

More information

Optical Storage Technology. MPEG Data Compression

Optical Storage Technology. MPEG Data Compression Optical Storage Technology MPEG Data Compression MPEG-1 1 Audio Standard Moving Pictures Expert Group (MPEG) was formed in 1988 to devise compression techniques for audio and video. It first devised the

More information

Multimedia Communications. Audio coding

Multimedia Communications. Audio coding Multimedia Communications Audio coding Introduction Lossy compression schemes can be based on source model (e.g., speech compression) or user model (audio coding) Unlike speech, audio signals can be generated

More information

Multimedia on the Web

Multimedia on the Web Multimedia on the Web Graphics in web pages Downloading software & media Digital photography JPEG & GIF Streaming media Macromedia Flash Graphics in web pages Graphics are very popular in web pages Graphics

More information

ITNP80: Multimedia! Sound-II!

ITNP80: Multimedia! Sound-II! Sound compression (I) Compression of sound data requires different techniques from those for graphical data Requirements are less stringent than for video data rate for CD-quality audio is much less than

More information

VC 12/13 T16 Video Compression

VC 12/13 T16 Video Compression VC 12/13 T16 Video Compression Mestrado em Ciência de Computadores Mestrado Integrado em Engenharia de Redes e Sistemas Informáticos Miguel Tavares Coimbra Outline The need for compression Types of redundancy

More information

Fundamentals of Video Compression. Video Compression

Fundamentals of Video Compression. Video Compression Fundamentals of Video Compression Introduction to Digital Video Basic Compression Techniques Still Image Compression Techniques - JPEG Video Compression Introduction to Digital Video Video is a stream

More 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 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

More information

CS 335 Graphics and Multimedia. Image Compression

CS 335 Graphics and Multimedia. Image Compression CS 335 Graphics and Multimedia Image Compression CCITT Image Storage and Compression Group 3: Huffman-type encoding for binary (bilevel) data: FAX Group 4: Entropy encoding without error checks of group

More information

Lossy compression CSCI 470: Web Science Keith Vertanen Copyright 2013

Lossy compression CSCI 470: Web Science Keith Vertanen Copyright 2013 Lossy compression CSCI 470: Web Science Keith Vertanen Copyright 2013 Digital audio Overview Sampling rate Quan5za5on MPEG audio layer 3 (MP3) JPEG s5ll images Color space conversion, downsampling Discrete

More information

Introducing Audio Signal Processing & Audio Coding. Dr Michael Mason Senior Manager, CE Technology Dolby Australia Pty Ltd

Introducing Audio Signal Processing & Audio Coding. Dr Michael Mason Senior Manager, CE Technology Dolby Australia Pty Ltd Introducing Audio Signal Processing & Audio Coding Dr Michael Mason Senior Manager, CE Technology Dolby Australia Pty Ltd Overview Audio Signal Processing Applications @ Dolby Audio Signal Processing Basics

More information

Compressed Audio Demystified by Hendrik Gideonse and Connor Smith. All Rights Reserved.

Compressed Audio Demystified by Hendrik Gideonse and Connor Smith. All Rights Reserved. Compressed Audio Demystified Why Music Producers Need to Care About Compressed Audio Files Download Sales Up CD Sales Down High-Definition hasn t caught on yet Consumers don t seem to care about high fidelity

More information

The Gullibility of Human Senses

The Gullibility of Human Senses The Gullibility of Human Senses Three simple tricks for producing LBSC 690: Week 9 Multimedia Jimmy Lin College of Information Studies University of Maryland Monday, April 2, 2007 Images Video Audio But

More information

VIDEO COMPRESSION STANDARDS

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

More information

Video coding. Concepts and notations.

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

More information

Digital video coding systems MPEG-1/2 Video

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

More information

5.9. Video Compression (1)

5.9. Video Compression (1) 5.9. Video Compression (1) Basics: video := time sequence of single images frequent point of view: video compression = image compression with a temporal component assumption: successive images of a video

More information

Data Representation. Reminders. Sound What is sound? Interpreting bits to give them meaning. Part 4: Media - Sound, Video, Compression

Data Representation. Reminders. Sound What is sound? Interpreting bits to give them meaning. Part 4: Media - Sound, Video, Compression Data Representation Interpreting bits to give them meaning Part 4: Media -, Video, Compression Notes for CSC 100 - The Beauty and Joy of Computing The University of North Carolina at Greensboro Reminders

More information

International Journal of Advance Research in Computer Science and Management Studies

International Journal of Advance Research in Computer Science and Management Studies Volume 3, Issue 6, June 2015 ISSN: 2321 7782 (Online) International Journal of Advance Research in Computer Science and Management Studies Research Article / Survey Paper / Case Study Available online

More information

International Journal of Emerging Technology and Advanced Engineering Website: (ISSN , Volume 2, Issue 4, April 2012)

International Journal of Emerging Technology and Advanced Engineering Website:   (ISSN , Volume 2, Issue 4, April 2012) A Technical Analysis Towards Digital Video Compression Rutika Joshi 1, Rajesh Rai 2, Rajesh Nema 3 1 Student, Electronics and Communication Department, NIIST College, Bhopal, 2,3 Prof., Electronics and

More information

Inserting multimedia objects in Dreamweaver

Inserting multimedia objects in Dreamweaver Inserting multimedia objects in Dreamweaver To insert a multimedia object in a page, do one of the following: Place the insertion point in the Document window where you want to insert the object, then

More information

Appendix 4. Audio coding algorithms

Appendix 4. Audio coding algorithms Appendix 4. Audio coding algorithms 1 Introduction The main application of audio compression systems is to obtain compact digital representations of high-quality (CD-quality) wideband audio signals. Typically

More information

Fundamentals of Perceptual Audio Encoding. Craig Lewiston HST.723 Lab II 3/23/06

Fundamentals of Perceptual Audio Encoding. Craig Lewiston HST.723 Lab II 3/23/06 Fundamentals of Perceptual Audio Encoding Craig Lewiston HST.723 Lab II 3/23/06 Goals of Lab Introduction to fundamental principles of digital audio & perceptual audio encoding Learn the basics of psychoacoustic

More information

Digital Image Representation Image Compression

Digital Image Representation Image Compression Digital Image Representation Image Compression 1 Image Representation Standards Need for compression Compression types Lossless compression Lossy compression Image Compression Basics Redundancy/redundancy

More information

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

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

More information

Digital Video Processing

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.

More information

Chapter 1. Digital Data Representation and Communication. Part 2

Chapter 1. Digital Data Representation and Communication. Part 2 Chapter 1. Digital Data Representation and Communication Part 2 Compression Digital media files are usually very large, and they need to be made smaller compressed Without compression Won t have storage

More information

Week 14. Video Compression. Ref: Fundamentals of Multimedia

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

More information

Introduction to LAN/WAN. Application Layer 4

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

More information

Introduction to Video Encoding

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

More information

AUDIOVISUAL COMMUNICATION

AUDIOVISUAL COMMUNICATION AUDIOVISUAL COMMUNICATION Laboratory Session: Audio Processing and Coding The objective of this lab session is to get the students familiar with audio processing and coding, notably psychoacoustic analysis

More information

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

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

More information

Obtaining video clips

Obtaining video clips Video Using video Carefully planned, well-executed video clips can make a dramatic difference in a multimedia project Use video only when all other methods (text, still images) are not enough; don t use

More information

Skill Area 325: Deliver the Multimedia content through various media. Multimedia and Web Design (MWD)

Skill Area 325: Deliver the Multimedia content through various media. Multimedia and Web Design (MWD) Skill Area 325: Deliver the Multimedia content through various media Multimedia and Web Design (MWD) 325.1 Understanding of multimedia considerations for Internet (13hrs) 325.1.1 Analyze factors affecting

More information

Tech Note - 05 Surveillance Systems that Work! Calculating Recorded Volume Disk Space

Tech Note - 05 Surveillance Systems that Work! Calculating Recorded Volume Disk Space Tech Note - 05 Surveillance Systems that Work! Surveillance Systems Calculating required storage drive (disk space) capacity is sometimes be a rather tricky business. This Tech Note is written to inform

More information

Compressed-Domain Video Processing and Transcoding

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

More information

Introducing Audio Signal Processing & Audio Coding. Dr Michael Mason Snr Staff Eng., Team Lead (Applied Research) Dolby Australia Pty Ltd

Introducing Audio Signal Processing & Audio Coding. Dr Michael Mason Snr Staff Eng., Team Lead (Applied Research) Dolby Australia Pty Ltd Introducing Audio Signal Processing & Audio Coding Dr Michael Mason Snr Staff Eng., Team Lead (Applied Research) Dolby Australia Pty Ltd Introducing Audio Signal Processing & Audio Coding 2013 Dolby Laboratories,

More information

Multimedia Standards

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

More information

Media player for windows 10 free download

Media player for windows 10 free download Media player for windows 10 free download Update to the latest version of Internet Explorer. You need to update your browser to use the site. PROS: High-quality playback, Wide range of formats, Fast and

More information

AUDIOVISUAL COMMUNICATION

AUDIOVISUAL COMMUNICATION AUDIOVISUAL COMMUNICATION Laboratory Session: Audio Processing and Coding The objective of this lab session is to get the students familiar with audio processing and coding, notably psychoacoustic analysis

More information

Topic 5 Image Compression

Topic 5 Image Compression Topic 5 Image Compression Introduction Data Compression: The process of reducing the amount of data required to represent a given quantity of information. Purpose of Image Compression: the reduction of

More information

Lecture 6: Compression II. This Week s Schedule

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

More information

Wireless Communication

Wireless Communication Wireless Communication Systems @CS.NCTU Lecture 6: Image Instructor: Kate Ching-Ju Lin ( 林靖茹 ) Chap. 9 of Fundamentals of Multimedia Some reference from http://media.ee.ntu.edu.tw/courses/dvt/15f/ 1 Outline

More information

Computer and Machine Vision

Computer and Machine Vision Computer and Machine Vision Deeper Dive into MPEG Digital Video Encoding January 22, 2014 Sam Siewert Reminders CV and MV Use UNCOMPRESSED FRAMES Remote Cameras (E.g. Security) May Need to Transport Frames

More information

Introduction to Video Compression

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

More information

Streaming Technologies Glossary

Streaming Technologies Glossary Streaming Technologies Glossary A ACELP.net ADSL AIFF Artifact Asf Asx Avi B Bitrate C C Capture card Codec CIF (QCIF) Client Industry standard audio compression technology developed by VoiceAge Corporation.

More information

CS 260: Seminar in Computer Science: Multimedia Networking

CS 260: Seminar in Computer Science: Multimedia Networking CS 260: Seminar in Computer Science: Multimedia Networking Jiasi Chen Lectures: MWF 4:10-5pm in CHASS http://www.cs.ucr.edu/~jiasi/teaching/cs260_spring17/ Multimedia is User perception Content creation

More information

Advanced Encoding Features of the Sencore TXS Transcoder

Advanced Encoding Features of the Sencore TXS Transcoder Advanced Encoding Features of the Sencore TXS Transcoder White Paper November 2011 Page 1 (11) www.sencore.com 1.605.978.4600 Revision 1.0 Document Revision History Date Version Description Author 11/7/2011

More information

JPEG. Wikipedia: Felis_silvestris_silvestris.jpg, Michael Gäbler CC BY 3.0

JPEG. Wikipedia: Felis_silvestris_silvestris.jpg, Michael Gäbler CC BY 3.0 JPEG Wikipedia: Felis_silvestris_silvestris.jpg, Michael Gäbler CC BY 3.0 DFT vs. DCT Image Compression Image compression system Input Image MAPPER QUANTIZER SYMBOL ENCODER Compressed output Image Compression

More information

Multimedia Signals and Systems Motion Picture Compression - MPEG

Multimedia Signals and Systems Motion Picture Compression - MPEG Multimedia Signals and Systems Motion Picture Compression - MPEG Kunio Takaya Electrical and Computer Engineering University of Saskatchewan March 9, 2008 MPEG video coding A simple introduction Dr. S.R.

More information

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 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

More information

ITEC310 Computer Networks II

ITEC310 Computer Networks II ITEC310 Computer Networks II Chapter 29 Multimedia Department of Information Technology Eastern Mediterranean University 2/75 Objectives After completing this chapter you should be able to do the following:

More information

EE482: Digital Signal Processing Applications

EE482: Digital Signal Processing Applications Professor Brendan Morris, SEB 3216, brendan.morris@unlv.edu EE482: Digital Signal Processing Applications Spring 2014 TTh 14:30-15:45 CBC C222 Lecture 13 Audio Signal Processing 14/04/01 http://www.ee.unlv.edu/~b1morris/ee482/

More information

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

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,

More information

Introduction to Video Encoding

Introduction to Video Encoding Introduction to Video Encoding Preben N. Olsen University of Oslo and Simula Research Laboratory preben@simula.no August 26, 2013 1 / 37 Agenda 1 Introduction Repetition History Quality Assessment Containers

More information

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

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

More information

VIDEO COMPRESSION. Image Compression. Multimedia File Formats. Lossy Compression. Multimedia File Formats. October 8, 2009

VIDEO COMPRESSION. Image Compression. Multimedia File Formats. Lossy Compression. Multimedia File Formats. October 8, 2009 File Formats Lossy Compression Image Compression File Formats VIDEO COMPRESSION 121 (Basics) video := time sequence of single images frequent point of view: video compression = image compression with a

More information

Megapixel Video for. Part 2 of 4. Brought to You by. Presented by Video Security Consultants

Megapixel Video for. Part 2 of 4. Brought to You by. Presented by Video Security Consultants rought to You by 2009 Video Security Consultants Presented by Part 2 of 4 A1 Part 2 of 4 How to Avert a Compression Depression Illustration by Jerry King While bandwidth is widening, larger video systems

More information

Georgios Tziritas Computer Science Department

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

More information