Introduction to Audiovisual Introduction to Audiovisual - PowerPoint PPT Presentation

Introduction to Audiovisual Introduction to Audiovisual Introduction to Audiovisual Compression Basics and Compression Basics and Compression Basics and Systems Systems Systems ���������������� ��������������� ���������������� ��������������������������������� ��������������������������������� Audiovisual Compression: from Basics to Systems, Fernando Pereira

Audiovisual Communication Systems ... Audiovisual Communication Systems ... Audiovisual Communication Systems ... Transference of image, audio and video Transference of image, audio and video information through space, time, or space information through space, time, or space and time simultaneously and time simultaneously Audiovisual Compression: from Basics to Systems, Fernando Pereira

The Importance of the User … … The Importance of the User … The Importance of the User Audiovisual Compression: from Basics to Systems, Fernando Pereira

We All Communicate … … We All Communicate … We All Communicate Audiovisual Compression: from Basics to Systems, Fernando Pereira

Sensations, Perceptions and Emotions … … Sensations, Perceptions and Emotions … Sensations, Perceptions and Emotions Audiovisual Compression: from Basics to Systems, Fernando Pereira

Aural and Visual Transducers Aural and Visual Transducers Aural and Visual Transducers ������������������������������������������������������������������ ���������������������������������������������������������������� ���������������������������������������������������������������� ����������������������������������������������� common examples include microphones, loudspeakers, thermometers, position and pressure sensors � Audiovisual Compression: from Basics to Systems, Fernando Pereira

Communicating Since a Long Time Ago … … Communicating Since a Long Time Ago … Communicating Since a Long Time Ago Audiovisual Compression: from Basics to Systems, Fernando Pereira

And After Telecommunicating … … And After Telecommunicating … And After Telecommunicating Audiovisual Compression: from Basics to Systems, Fernando Pereira

What do the Users Want ? What do the Users Want ? What do the Users Want ? � Information � Entertainment � Communication � Games � Education � Shopping � … Audiovisual Compression: from Basics to Systems, Fernando Pereira

How can Users/Clients be Convinced ? How can Users/Clients be Convinced ? How can Users/Clients be Convinced ? � Satisfaction of personal needs � Added value, new capabilities � Interoperability � Quality and robustness � Content variety � (Low) cost of equipment and usage � Easy usage Audiovisual Compression: from Basics to Systems, Fernando Pereira

Satisfaction: Quality versus Service Satisfaction: Quality versus Service Satisfaction: Quality versus Service The minimum required quality of service depends on the service in question: � Facsimile � Digital image (bi3level, grey or colour) � Analogue TV � Videotelephony � Videoconference � Digital television � High definition digital television Audiovisual Compression: from Basics to Systems, Fernando Pereira

Personal Communications versus Broadcasting Personal Communications versus Broadcasting Personal Communications versus Broadcasting � Real3time versus ����������� � Point3to3point versus point3 multipoint � Unidirectional versus bidirectional Audiovisual Compression: from Basics to Systems, Fernando Pereira

Passive versus Interactive Services Passive versus Interactive Services Passive versus Interactive Services Critical delay requirements for interactive services ! Audiovisual Compression: from Basics to Systems, Fernando Pereira

Analogue Communications World … … Analogue Communications World … Analogue Communications World Audiovisual Compression: from Basics to Systems, Fernando Pereira

Digital Communications World … … Digital Communications World … Digital Communications World Digital representation bitrate Claude Elwood SHA66O6, SHA66O6, 1916 19163 32001 2001 Claude Elwood Channel capacity Harry 6YQUIST, , 1889 18893 3 1976 1976 Harry 6YQUIST Audiovisual Compression: from Basics to Systems, Fernando Pereira

Bit Jumping … … Bit Jumping … Bit Jumping Audiovisual Compression: from Basics to Systems, Fernando Pereira

Why is there a 6eed for Compression/Coding ? ? Why is there a 6eed for Compression/Coding ? Why is there a 6eed for Compression/Coding For example, an image is created and consumed as a set of M × × × 6 luminance and chrominance samples with a × certain number of bits per sample (L) The total number of bits 3 and thus bandwidth and memory – needed to digitally represent an image is HUGE !!! Without compression ... Audiovisual Compression: from Basics to Systems, Fernando Pereira

The Compression/Coding Miracle … … The Compression/Coding Miracle … The Compression/Coding Miracle Encoder Decoder Audiovisual Compression: from Basics to Systems, Fernando Pereira

Digital TV: Only an Example Digital TV: Only an Example Digital TV: Only an Example � Original bitrate (non compressed): 25 images/s with 720 × × × × 576 luminance samples and 360 × × × × 576 samples for each chrominance, at 8 bit/sample × 25 = 166 Mbit/s [(720 × × × × 576) + 2 × × × × (360 × × × × 576)] × × × 8 × × × × � Practical bitrate (compressed): 2 Mbit/s ≈ 80 => Required Compression Factor: 166/2 ≈ ≈ ≈ The difference between compression/coding or not implies the existence or not of many largely used services. Audiovisual Compression: from Basics to Systems, Fernando Pereira

The Secret of the Miracle … … The Secret of the Miracle … The Secret of the Miracle � REDU6DA6CY REDU6DA6CY – Related � to the similarities, correlations and predictability between the samples of images, video or audio. � IRRELEVA6CY IRRELEVA6CY – Related � to the information inperceptible for the human visual or auditory systems. Audiovisual Compression: from Basics to Systems, Fernando Pereira

US Video Compression/Coding Patents (19903 3 US Video Compression/Coding Patents (19903 US Video Compression/Coding Patents (1990 2007) 2007) 2007) Audiovisual Compression: from Basics to Systems, Fernando Pereira

The Consequences of the Miracle (1) … … The Consequences of the Miracle (1) The Consequences of the Miracle (1) … Audiovisual Compression: from Basics to Systems, Fernando Pereira

The Consequences of the Miracle (2) … … The Consequences of the Miracle (2) The Consequences of the Miracle (2) … Audiovisual Compression: from Basics to Systems, Fernando Pereira

The Impact of Interoperability … … The Impact of Interoperability … The Impact of Interoperability Audiovisual Compression: from Basics to Systems, Fernando Pereira

Copying: The Snowball Effect Copying: The Snowball Effect Copying: The Snowball Effect Audiovisual Compression: from Basics to Systems, Fernando Pereira

Business Model: The Key to Success ... Business Model: The Key to Success ... Business Model: The Key to Success ... A business model is the method of doing business by which a product/service can sustain itself 3 that is, generate revenue. Some business models are quite simple. Other models can be more complex such as free television. The broadcaster is part of a complex network of distributors, content creators, advertisers, and listeners or viewers. Who makes money and how much is not always clear at the outset. � Digital representations and networks give rise to new kinds of business models, since acquiring, transmitting, and storing information (now just bits) became much easier. � But it is also likely to reinvent ‘old’ models such as auctions. 6ew and interesting variations of old models should be expected in the future. Audiovisual Compression: from Basics to Systems, Fernando Pereira

6ew Systems and … … 6ew Business Models 6ew Business Models … … 6ew Systems and … 6ew Business Models … 6ew Systems and iPod may play the following audio formats: MP3, WAV, AAC, Protected AAC Protected AAC, AIFF and Apple Lossless. Audiovisual Compression: from Basics to Systems, Fernando Pereira

The YouTube YouTube Revolution Revolution … … The YouTube Revolution … The Audiovisual Compression: from Basics to Systems, Fernando Pereira

Too Much is Too Much … … Too Much is Too Much Too Much is Too Much … Audiovisual Compression: from Basics to Systems, Fernando Pereira

Filtering TV … … Filtering TV Filtering TV … Audiovisual Compression: from Basics to Systems, Fernando Pereira