Organisation internationale de normalisation

Record of AhG meetings

1. AhG on 3D Audio Phase II

A meeting of the AhG on 3D Audio was held the 1300 – 1800 hrs on the Sunday prior to the 114^th meeting of WG11 at the MPEG meeting venue.

3D Audio Phase 2 CEs

Total Components Coding (TCC)

Lukasz Januszkiewicz, Zylia, presented

m37930

Zylia Poznan Listening Test Site Properties

Jakub Zamojski, Lukasz Januszkiewicz, Tomasz Zernicki

The contribution presents details on the Zylia listening room. This room meets BS.1116 requirements in terms of

• 
  Aspect ratio
  
• 
  Reverberation time as a function of frequency
  

Speakers are on the surface of a cylinder with radius of approximately 3 meters.

Lukasz Januszkiewicz, Zylia, presented

m37932

Corrections and clarifications on Tonal Component Coding

Lukasz Januszkiewicz, Tomasz Zernicki

The contribution proposes syntax changes

• 
  Add one bit and define a 2-bit field tccMode in the config()
  

This permits a one or alternatively two TCC “packets” of data per CPE.

Other corrections are proposed that that are either purely editorial or make specification text conform to reference software.

All experts present in the AhG meeting agreed to recommend to the Audio Subgroup to incorporate all changes in the contribution into a Study on MPEG-H 3D Audio DAM3 output document.
Christian Neukam, FhG-IIS, presented

m37947

Listening Test Results for TCC from FhG IIS

Sascha Dick, Christian Neukam

The contribution reports on a cross-check listening test on the proposed Zylia TCC Core Experiment. In the test

• 
  Sys1 RM
  
• 
  Sys2 CE technology using OFDT-based synthesis
  

In absolute MUSHRA scores, no items different, mean not different

In differential MUSHRA scores, 1 item better for Sys2, mean not different, but mean value better by 1 MUSHRA point.

Lukasz Januszkiewicz, Zylia, presented

m37933

Low Complexity Tonal Component Coding

Tomasz Zernicki, Lukasz Januszkiewicz, Andrzej Rumiaski, Marzena Malczewska

The contribution, along with the previous cross-checks, consists of a complete CE proposal.

The contribution explores whether a Low Compexity TCC might be appropriate for the Low Complexity Profile. The “RM” baseline was

• 
  MPEG-H 3DA LC RQE with IGF active
  

The point of the experiment is that the TCC is able to work with the IGF tool. The contribution reports on a listening test on the proposed Zylia TCC Core Experiment. In the test

• 
  Sys1 RM
  
• 
  Sys2 CE technology using ODFT-based synthesis
  

In absolute MUSHRA scores, no items different, mean not different

In differential MUSHRA scores, 3 items better for Sys2, mean better, mean value better by 1.5 MUSHRA point.

The presenter noted that the number of Tonal Components is typically small (e.g. less than 3 per core channel), in which case the Time Domain tone synthesis technique would fit with a Low Complexity use case. The presenter noted that low complexity could be guaranteed via restrictions

The Chair clarified that the following issues and questions are on the table:

• 
  TCC works with IGF (as demonstrated in the listening test)
  
• 
  We might assume that TD synthesis is higher quality that ODFT synthesis
  
• 
  We need to investigate the maxium number of TC per core audio channel
  

This will continue to be discussed and brought up later in the week.