Organisation internationale de normalisation

Broadcast Contribution Mode

The contribution notes that MPEG-H 3D Audio has been developed for use as a contribution coder. However, it may be well suited, with some restrictions or modificatoins, to operate as a contribution coder. For example, the presenter showed the figure at http://mpeghaa.com/MPEG-H%20Audio%20Alliance.pdf

For example, no rendering is needed when operating as a contribution coder.

What is proposed is:

A new value of speakerLayoutType == 3 is defined, which can only be used with a signalled referenceLayout.

Contribution Mode bitstreams shall have the following additional restrictions:

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  bsNumSignalGroups == 0 (one single signal group)
  
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  SignalGroupType == 0 (channel signal group)
  
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  differsFromReferenceLayout[0] == 0 (no audioChannelLayout in the signal group)
  
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  core coder delay lines for compensation of SBR, MPS212, shall be applied
  
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  Content of extension elements shall not be processed in the decoder but shall be made available to an external framework
  

Deep Sen, Qualcomm, noted that HOA mode has a “mezzanine format” of at most 6 audio channels. The presenter stated that he expected that the proposed operation mode would support the HOA “mezennine format.”

Oliver Weubbolt, Technicolor, asked about the structure of the “metadata carrier” mechanism. The presenter stated that the 3D Audio bitstream extension element is used to transport metadata.

Subject to resolution of proper support for the HOA “mezzanine format,” it was the consensus of the Audio subgroup to incorporate this Contribution Coder Mode of Operation into MPEG-H Phase 2.

Michael Kratschmer, FhG-IIS, presented

m36526

Tool for Advanced Loudness Control

Michael Kratschmer, Bernhard Neugebauer, Fabian Kuech

The contribution notes that loudness normalization is essential to comply with various regulations (e.g. EBU R128, ATSC A/85). It further notes that the 3D Audio decoder supports various user interactions, including ones that might change the loudness of the output signal.

In order to insure the compliance to loudness regulations, the contribution proposes a new tool Advanced Loudness Control.

For example, user interaction may result in the following adjustment of dialog/sound scene loudness levels:

The contribution proposes to define a new ID_MAE_LOUDNESS_COMPENSATION, and if present, then the loudness compensation tool is enabled.

Bitrate and Complexity

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  If 5.1 channel bed and 3 languages, then additional bitrate is 0.1 kb/s
  
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  If user adjusts the dialog level, then tool complexity is 0.007 WMOPS.