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ABSTRACT
This article describes the digital “compressed” format into which are converted sounds and pictures, after the first step of digitization generating their “digital native format”, representing the results of the measurements of sounds or pictures. The objective of the digital compression process is to reduce the number of binary digits in this native format. This reduction is based on the analysis of redundant information perceived by our senses. However, when badly adjusted, this process can generate artefacts in the reproduced sounds or pictures. This article describes basic principles, tools used, and the parameters to take into account for each medium.
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Jean-Noël GOUYET: Digital Media Engineering and Management - Former head of research at the Institut national de l'audiovisuel (Ina)
INTRODUCTION
Professionals and private individuals alike have to produce, manipulate, store, manage, exchange, broadcast and distribute digital media "encoded" in various formats, called "essence" formats, and encapsulated in extremely numerous and varied storage and transport "container formats".
This "Panorama of digital media" dossier, comprising six articles, aims to provide a definition, description of the characteristics, mapping and classification of these different digital media formats.
The first article
This second article [TE 5 366] presents an overview of digital, audio, still image and video compression formats that reduce the amount of data in native formats, making them easier to store and distribute.
The third article
The fourth article
The fifth article
The Ultimate Scientific and Technical Reference
KEYWORDS
Redundancy | digital media | compression format
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Signal processing and its applications
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Panorama of digital media
"Digital "compression
Bibliography
Principles
- (1) - GOUYET (J.-N.) - Systèmes audio et vidéo numériques. - Codage de source – Réduction de débit, Chap. 10, Institut national de l'audiovisuel, Techniques et production audiovisuelles, Paris, ISBN 2-86938-030-5 (1993).
Audio
Standards and norms
Audio
- Information technology – Coding of moving pictures and associated audio for digital storage media at up to about 1,5 Mbit/s – Part 3: Audio http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=22412 - ISO/IEC 11172-3 - 1993
- Information technology – Generic coding of moving pictures and associated audio information – Part 3: Audio http://www.iso.org/iso/iso_catalogue/catalogue_ics/catalogue_detail_ics.htm?csnumber=22991...
Directory
Organizations – Federations – Associations (non-exhaustive list)
ATSC (Advanced Television Systems Committee) http://www.atsc.org/
DCI (Digital Cinema Initiatives LLC) http://www.dcimovies.com/
EBU (European Broadcasting Union)...
The Ultimate Scientific and Technical Reference
