Organisation internationale de normalisation

Maintenance

MPEG-4

Tomoyasu Komori, NHK, presented

m36423

A proposed update to ISO/IEC 14496-3

Takehiro Sugimoto, Yasushige Nakayama, Tomoyasu Komori, Toru Chinen, Hiroyuki Ehara

The contribution presented the NHK roadmap for 22.2 channel audio 8K video satellite broadcast service.

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  This service was demonstrated in 2015 using 1.5 Mb/s bit rate for audio.
  
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  In 2018 it is anticipated to broadcast satellite to the home.
  
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  This is in preparation for 22.2/8k broadcasts of Olympics in 2020. This service uses MPEG-4 AAC.
  

It is anticipated that in 202x Japan will use MPEG-H 3D Audio for terrestrial broadcasting, e.g. to the Japanese home. In this case the audio bit budget might be 512 kb/s.

What is requested is:

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  Level and profile for 22.2 channel audio programs
  
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  Downmixing method for downmixing 22.2 channel programs to 5.1 channel loudspeaker presentation.
  

The Chair requested that experts from Japan bring information to a future MPEG meeting that indicated how well the downmix system works for 22.2. channel production under the constraint of 5.1 and stereo monitoring.

It was the consensus of the Audio subgroup to take the document in this contribution and make it Working Draft for 14496-3:2009/AMD 6.

Adrian Murtaza, FhG, presented

m36514

Clarification on MPEG-4 AAC-ELD

Markus Schnell, Manfred Lutzky, Conrad Benndorf, Adrian Murtaza

The contribution proposed clarifications to the AAC-ELD text, specifically to fully specify the method to calculate the filterbank coefficients in the case of 96 kHz sampling rates and the use of “downscaled” (i.e. lowest delay) filterbank implementation. This is given for both MDCT and QMF filterbanks. The contribution provides additional text to specify a calculation method.

It was the consensus of the Audio subgroup to take the document in this contribution and make it 14496-3:2009/DCOR 7.

Adrian Murtaza, FhG, presented

m36572

Update to MPEG-4 HE-AAC Level 6 conformance data and tools

Adrian Murtaza, Nikolaus Rettelbach, Tobias Schwegler, Stephan Schreiner

The contribution proposed to

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  change the level 6 and 7 HE-AAC conformance streams to use the SBR conformance naming convention used elsewhere in the conformance repository.
  
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  Revise the SBR conformance tool to
  
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    be responsive to the bitstream name
    
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    to process 7.1 channel signals
    

It was the consensus of the Audio subgroup

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  Incorporate the new conformance streams names into ISO/IEC 14496-26:2010 DAM 4, AAC Additional Multichannel Conformance Data
  
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  Incorporate the new SBR conformance tool into ISO/IEC 14496-5:2001/FDAM 37, New levels for AAC profiles, uniDRC support, AAC block length parameter corrections