Information technology — Coding of audio-visual objects — Part 12: ISO base media file format — Amendment 1: DRC Extensions

Technologies de l'information — Codage des objets audiovisuels — Partie 12: Format ISO de base pour les fichiers médias — Amendement 1: Extensions DRC

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Publication Date
26-Apr-2017
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26-Apr-2017
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9599 - Withdrawal of International Standard
Completion Date
16-Dec-2020
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ISO/IEC 14496-12:2015/Amd 1:2017 - DRC Extensions
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INTERNATIONAL ISO/IEC
STANDARD 14496-12
Fifth edition
2015-12-15
AMENDMENT 1
2017-03
Information technology — Coding of
audio-visual objects —
Part 12:
ISO base media file format
AMENDMENT 1: DRC Extensions
Technologies de l’information — Codage des objets audiovisuels —
Partie 12: Format ISO de base pour les fichiers médias
AMENDEMENT 1: Extensions DRC
Reference number
ISO/IEC 14496-12:2015/Amd.1:2017(E)
©
ISO/IEC 2017

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ISO/IEC 14496-12:2015/Amd.1:2017(E)

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ii © ISO/IEC 2017 – All rights reserved

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ISO/IEC 14496-12:2015/Amd.1:2017(E)

Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are
members of ISO or IEC participate in the development of International Standards through technical
committees established by the respective organization to deal with particular fields of technical
activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international
organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the
work. In the field of information technology, ISO and IEC have established a joint technical committee,
ISO/IEC JTC 1.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
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World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: w w w . i s o .org/ iso/ foreword .html.
Amendment 1 to ISO/IEC 14496‑12:2015 was prepared by Joint Technical Committee ISO/IEC JTC 1,
Information technology, Subcommittee SC 29, Coding of audio, picture, multimedia and hypermedia
information.
© ISO/IEC 2017 – All rights reserved iii

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ISO/IEC 14496-12:2015/Amd.1:2017(E)
Information technology — Coding of audio-visual
objects —
Part 12:
ISO base media file format
AMENDMENT 1: DRC Extensions
Page 1, Normative references
Add the following new reference:
ISO/IEC 23003-4:2015/Amd.1, Information technology — MPEG audio technologies — Part 4: Dynamic
range control, AMENDMENT 1: Parametric DRC, gain mapping and equalization tools.
Replace the normative reference:
ITU-R, Recommendation ITU-R BS.1770-3. Algorithm to measure audio programme loudness and true-
peak audio level, August 2012.
with:
ITU-R, Recommendation ITU-R BS.1770-4. Algorithms to measure audio programme loudness and true-
peak audio level, October 2015.
Page 2, Terms and definitions
Add the following new definition after 3.1.8 and adjust subsequent term numbers:
3.1.9
mod
modulo operator: (x mod y) = x-y floor (x/y)
Page 160, 12.2.3.1
Add the following paragraph at the end of the subclause:
Encoders should encode the DRC-related boxes in the AudioSampleEntry in the order given in
12.2.3.2. Decoders may ignore and discard the DRC‑related boxes if they are not in that order. DRC‑
related boxes include ChannelLayout, DownMixInstructions, DRCCoefficientsBasic,
DRCInstructionsBasic, DRCCoefficientsUniDrc, DRCInstructionsUniDrc, and
UniDrcConfigExtension. The DownMixInstructions and DRCInstructionsUniDrc box
cannot occur more than once if the box has version==1, but it can occur multiple times if version==0.
© ISO 2017 – All rights reserved 1

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ISO/IEC 14496-12:2015/Amd.1:2017(E)

Page 161, 12.2.3.2
Replace the definition of AudioSampleEntry and AudioSampleEntryV1 with:
class AudioSampleEntry(codingname) extends SampleEntry (codingname){
  const unsigned int(32)[2] reserved = 0;
  template unsigned int(16) channelcount = 2;
  template unsigned int(16) samplesize = 16;
  unsigned int(16) pre_defined = 0;
  const unsigned int(16) reserved = 0 ;
  template unsigned int(32) samplerate = { default samplerate of media}<<16;
  // optional boxes follow
  Box ();    // further boxes as needed
  ChannelLayout();
  DownMixInstructions() [];
  DRCCoefficientsBasic() [];
  DRCInstructionsBasic() [];
  DRCCoefficientsUniDRC() [];
  DRCInstructionsUniDRC() [];
  // we permit only one DRC Extension box:
  UniDrcConfigExtension();
  Box ();    // further boxes as needed
}
aligned(8) class SamplingRateBox extends FullBox('srat') {
  unsigned int(32) sampling_rate;
}
class AudioSampleEntryV1(codingname) extends SampleEntry (codingname){
  unsigned int(16) entry_version;  // must be 1,
            // and must be in an stsd with version ==1
  const unsigned int(16)[3] reserved = 0;
  template unsigned int(16) channelcount;  // must be correct
  template unsigned int(16) samplesize = 16;
  unsigned int(16) pre_defined = 0;
  const unsigned int(16) reserved = 0 ;
  template unsigned int(32) samplerate = 1<<16;
  // optional boxes follow
  SamplingRateBox();
  Box ();    // further boxes as needed
  ChannelLayout();
  DownMixInstructions() [];
  DRCCoefficientsBasic() [];
  DRCInstructionsBasic() [];
  DRCCoefficientsUniDRC() [];
  DRCInstructionsUniDRC() [];
  // we permit only one DRC Extension box:
  UniDrcConfigExtension();
  Box ();    // further boxes as nee
...

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