International organisation for standardisation organisation internationale de normalisation

AhG on DRC and 3D Audio

The AHG on Dynamic Range Control (DRC) and 3D Audio and Audio Maintenance met Sunday October 27 1000-1800 hrs at the MPEG meeting venue.

1. 3D Audio Binauralization CE

Listening Test Site Reports

Representatives from each listening test site presented

m31214	Qualcomm's Binaural CE Listening Lab – Conditions & Methodology	[e-mail], [e-mail], [e-mail], [e-mail]
m31272	Listening test report of ETRI for MPEG-H 3D Audio Binaural CE	Taejin Lee, Jeongil Seo, Kyeongok Kang
m31298	Listening test report of YSU for MPEG-H 3D Audio Binaural CE	Taegyu Lee, Henney Oh, Young-cheol Park, Dae Hee Youn
m31358	Samsung Listening Test for 3D Audio Binaural Core Experiment	Namsuk Lee, Sang Bae Chon, Sunmin Kim
m31424	Orange listening tests for the CE on RM0-CO binauralization	Gregory Pallone
m31435	Fraunhofer IIS Listening Test Results for Binaural CE for MPEG-H 3D Audio	Simone Füg, Jan Plogsties
m31467	Huawei listening test report for the binauralization CE	Peter Grosche, Panji Setiawan

The Chair presented a report on the combined data

m31414

MPEG-H 3D Audio Binaural CE Subjective Test Results

Schuyler Quackenbush

Technical Descriptions

Nils Peters, Qualcomm, presented

m31211

Technical Description of Qualcomm's Candidate for the Binaural Core Experiment

Pei Xiang, Nils Peters, Martin Morrell, Deep Sen

• 
  Single band
  
• 
  Direct and Early reflection per loudspeaker
  
• 
  Late Reverberation is stereo
  
• 
  Qualcomm technology essentially same as Phase 1 submission - model (direct path = early reflection + hrtf) and late-reverb.
  
• 
  Only difference (from Phase 1) is - smaller reverb tail & adaptive reverb gain
  

Henney Oh, WILUS, presented both the ETRI and Yonsei/WILUS contributions

m31271	Description of ETRI proposal for MPEG-H 3D Audio Binaural CE	Jeongil Seo, Yong Ju Lee, Taejin Lee, Seungkwon Beack, Kyeongok Kang
m31297	Description of YSU proposal for MPEG-H 3D Audio Binaural CE	Taegyu Lee, Henney Oh, Young-cheol Park, Dae Hee Youn

ETRI/Yonsei/WILUS jointly propose a binaural rendering system, but two different versions were submitted with different tuning parameters.

Summary of submission technologies;

• 
  Frequency-varying filter-length for D&E (Direct & Early Reflection) - truncate in accordance with the RT20 of the BRIR
  
• 
  Integrated energy decay matching (EDM) for LR (Late Reverberation)
  
• 
  Inter-aural coherence matching (ICM) for LR
  
• 
  1-tap TDL (Tapped Delay Line) for SBR bands (optional)
  

Different parameter optimization Yonsei/WILUS and ETRIMultiband, QMF

Listening test results analysis based on difference scores with RM0;

• 
  Sys3 (Yonsei/WILUS, HQ mode) is the only system statistically better in overall sense
  
• 
  Sys3 is the unique system that is statistically no worse but 3 items are better
  

Computation complexity of submitted technologies;

• 
  FoM_complexity of Sys3 is 92.84
  
• 
  FoM_complexity of Sys5 is 94.62
  

Gregory Pallone, Orange, presented

m31421

Technical Description of the Orange proposal for the Binaural CE on RM0-CO

Gregory Pallone, Marc Emerit

• 
  Same technology as in HOA-RM0
  
• 
  Single band
  
• 
  DE, LR split processing
  

Only want to standardize A (DE) and B (LR) coefficients, not means to get A, B from BRIR. Could provide informative code for getting A, B from BRIR.

Another contribution suggests a normative interface for the A, B.

Jan Plogsties, FhG-IIS, presented

m31437

Binaural Core Experiment - Fraunhofer IIS System Description

Simone Füg, Jan Plogsties

• 
  Multiband, QMF, up to 48 bands (18 kHz), constant for all sub-bands
  
• 
  DE/LR boundary BRIR adaptive
  
• 
  LR is a stereo downmix processed by frequency-adaptive IIR filtering.
  

Panji Setiawan, Huawei, presented

m31468

Technical Description of the Huawei Binaural CE proposal

Simone Fontana, Karim Helwani, Peter Grosche, Panji Setiawan,

• 
  Multiband, QMF
  

Comments

Taegyu Lee, Yonsei University, presented

m31311

Comments on the evaluation methodology for the computational complexity of binaural renderer

Taegyu Lee, Henney Oh, Young-cheol Park, Dae Hee Youn

This contribution presents comments and suggestions to help to understand and clarify the Figure of Merit (FoM) for binaural CE. It notes that the evaluation methodology for block-wise fast convolution consented in the 105th MPEG meeting has a bug. The revised evaluation methodology is presented.

The presentation gave complexity issue between processing domains.

• 
  When bitrate is 512kbps, the binaural processing in the QMF domain does not require 20 times QMF synthesis. Thus, binaural processing in QMF domain has significant computational gain for the QMF domain input signals.
  
• 
  When bitrate is 1.2Mbps, the 22 times QMF analysis and 2 times QMF synthesis is required to the binaural processing in QMF domain.
  

Using a revised evaluation methodology, revised FoMs of each submission of binaural CE are presented. Matlab script for calculation of each Binaural CE submission is provided.

The presenter provided Excel spreadsheets containing computational complexity of each submission for binaural CE and the chair made the spreadsheets available to the AhG members.

It was decided that Audio experts will check the spreadsheets.

Disussion

The Chair presented the combined listening test data, but now with proponent names.

• 
  Single band, time domain Qualcomm, Orange,
  
• 
  Multi band, SBR QMF ETRI, Yonsei, FhG, Huawei, RM0
  

Recommendation

• 
  That the Audio subgroup further analyse the architectures,
  
• 
  Discuss whether architecture is used for only a range of bitrates
  
• 
  Gather and check complexity numbers
  
• 
  Consider issues of architecture unification
  

2. Submissions to CfP on DRC

Toru Chinen, Sony, presented

m31359

Technical description of Sony proposal for Dynamic Range Control Technology

Hiroyuki Honma, Runyu Shi, Toru Chinen, Yuki Yamamoto, Mitsuyuki Hatanaka, Masayuki Nishiguchi

• 
  Builds on the apple proposal (from 104^th meeting)
  

Fabian Kuech, FhG-IIS, presented

m31384

Description of the Fraunhofer IIS Submission for the DRC CfP

Fabian Kuech, Christian Uhle

• 
  DRC
  
• 
  Loudness control
  
• 
  Clipping Prevention (function of DRC and LC)
  
• 
  Guided limiter
  
• 
  (Peak limiter), if no gPL provided
  
• 
  Builds on the apple proposal (from 104^th meeting), but adds gCP and PL.
  
• 
  gCP uses the same syntax and structures as a DRC gain sequence.
  

Frank Baumgarte, Apple, presented

m31471	Description of Apple's proposal considering the CfP on Dynamic Range Control Technology	Frank Baumgarte, David Singer
m31472	Apple's Dynamic Range Control Proposal: Listening Test Results	Frank Baumgarte, Fabian Kuech
m31473	Apple's Dynamic Range Control Proposal: Evaluation	Frank Baumgart

Apple’s submission for the DRC CfP includes an improved an enhanced DRC tool compared to the proposal from the 104^th meeting. It is a universal tool that supports time-domain and sub-band domain DRC. Multiband DRC is also supported in both domains. The gain interpolation is based on splines to achieve smooth DRC gain transitions. The corresponding enhancements in the Sample Entry of the file format (m31470) include a list of descriptors of the DRC effect to enable an informed choice of the most appropriate DRC at the decoder. Moreover, various configurations can be supported such as pre- and/or post-downmix DRC.

Listening test results at two testing sites (Apple, Fraunhofer IIS) show that the proposed DRC tool delivers transparent quality while the current MPEG DRC can introduce distortions in AAC when a fast-acting DRC is applied.

Evaluations of the proposed tool show a minor bit rate increase for the coded DRC gains versus the current MPEG standard. The complexity is low if the tool operates without using the time-domain DRC filterbank. Drc config

Recommendations

• 
  Seems that FhG-IIS proposal can be supported by Apple proposal, but need to check.
  
• 
  What is the impact of the Sony proposal considering the current Apple proposal . Need to check.
  

Recommendations and review of AhG Report

The AhG members reviewed the AhG report and agreed on the report’s recommendations made to the Audio subgroup.

4.