International organisation for standardisation organisation internationale de normalisation

8.2.2MPEG-D Spatial Audio Object Coding

Leonid Terentiev, FhG, presented

m16657

Clarifications regarding the MCU description

Heiko Purnhagen, Leonid Terentiev, Oliver Hellmut

The contribution clarifies which aspects of the MCU are normative and which are informative. The normative components include:

• 
  MCU interface and SAOC parameter estimation
  
• 
  Energy estimation in the SAOC encoder
  
• 
  Parameters of the combined bitstreams
  

Remaining components are informative. The normative text and an informative annex are supplied in the contribution.

It was the consensus of the Audio Subgroup that the proposed changes be adopted into the FCD text.

Heiko Purnhagen, Dolby, presented

m16681

Clarifications of transport and time-alignment in SAOC

Heiko Purnhagen, Andreas Hölzer, María Luis Valero

The contribution provides revised text for Clauses 4 and 7 of the SAOC FCD. The changes to Clause 4, on delay and synchronization, can be summarized as:

• 
  specifying time-alignment in SAOC decoder
  
• 
  specifying time-alignment in SAOC decoder and MPEG Surround decoder. This text presents decoding for “separate” and “integrated” SAOC/MPEG Surround processing.
  
• 
  specifying time-alignment for arbitrary core coders and for HE-AAC core coders with integrated processing.
  

These items are treated for “high-quality” and “low-delay” filterbank processing. Some aspects of this specification are still under development, with additional information expected at the next meeting.

The changes to Clause 7, transport, are in line with what is already specified in MPEG Surround, and can be summarized as:

• 
  clarification of time-alignment signaling
  

It was the consensus of the Audio Subgroup that the proposed changes be adopted into the FCD text.

Heiko Purnhagen, Dolby, presented

m16682

Transport of SAOC in MPEG-4 Audio

Heiko Purnhagen, Markus Schnell, Ralph Sperschneider

The contribution proposes a specification for how to transport SAOC in MPEG-4 Audio. This includes changes to MPEG-4 Audio (ISO/IEC 14496-3) and changes to SAOC (ISO/IEC 23003-2). It is patterned after the method used for MPEG Surround.

Special care is taken in the specification when AAC-ELD is the core coder since AAC-ELD uses the error resilient bitstream structure. The proposal does this in a way that may support per-frame payloads for other MPEG Audio codecs that might be specified in the future. It was noted that this part of the proposal has not been implemented in the MPEG-4 Audio reference code.

It was the consensus of the Audio Subgroup that the proposed text be incorporated into the CD on ALS Simple Profile.

Heiko Purnhagen, Dolby, presented

m16680

Information on SAOC Complexity

Jonas Engdegård, Heiko Purnhagen

The contribution gives information on the complexity of the various component tools of SAOC and combines these per-tool figures to give figures for a profile proposed in a companion input document.

It was the consensus of the Audio Subgroup that the portions of the text specifying complexity be incorporated into the SAOC FCD text. Depending on the decision on m16679, “Proposal for a set of profiles and levels for SAOC,” the text associated with Profiles may also be included in the FCD text.

Oliver Hellmuth, FhG, presented

m16679

Proposal for a set of profiles and levels for SAOC

Jonas Engdegard, Oliver Hellmuth, Juergen Herre, Johannes Hilpert, Werner Oomen, Heiko Purnhagen, Leonid Terentiev

The contribution defines two profiles for SAOC:

• 
  SAOC Baseline Profile
  
• 
  SAOC Low Delay Profile
  

The profile and level definition is summarized here: