International organisation for standardisation organisation internationale de normalisation

Text, Conformance and Reference Software

Max Neuendorf, FhG, presented

m24863

Proposed additions to DCOR1 of USAC

Julien Robilliard, Andreas Niedermeier

The contribution presents some additional editorial and technical corrections to the USAC specification. The proposed technical changes are

• 
  Removal of delay in MPS tool that was “left over” from MPEG Surround low-power mode. It was noted that this change makes the Verification Test Report bitstreams “sub-optimal.” The Chair suggested that the USAC decoder have an “ifdef” statement that permits the Verification Test Report bitstreams to be decoded to produce exactly the Verification Test Report waveforms.
  
• 
  In the case that there is residual coding without phase information, the text is augmented to make it clear that all phase information is set to zero. This has an impact on text and reference software.
  
• 
  PVC corrections – text is incorrect but reference software is correct.
  

In addition, several purely editorial changes were proposed.

It was the consensus of the Audio Subgroup to adopt all changes proposed in the contribution into a Study on DCOR 1 of USAC.

Daniel Fischer, FhG, presented

m24861

Proposed Update of WD 23003-3 AMD1 USAC Conformance

Max Neuendorf, Daniel Fischer, Julien Robilliard

The contribution presents an update to the USAC conformance working draft document. Changes can be summarized as:

• 
  New description of inter-TES test procdure
  
• 
  New description of PVC test procdure
  
• 
  New description of LPD core mode test procdure
  

Finally, the contribution gives a URL, username and password for download of conformance stream information.

Eunmi Oh, Samsung, presented some additional text that describes the phase coding conformance streams.

It was the consensus of the Audio Subgroup to incorporate the additions proposed in the contribution and the additions proposed by Samsung into ISO/IEC 23003-3:2012/PDAM 1, USAC Conformance. The Chair asked for NBs that will support the request for amendment: DE, US, DNB, CA, KR, JP.

Daniel Fischer, FhG, presented

m24862

Proposed Corrections to the USAC Reference Software

Andreas Niedermeier, Daniel Fischer

The contribution proposes changes to the USAC reference software. Changes can be summarizes as:

• 
  Relabel the source code directory names to change “mpeg4” to “mpegD_usac”
  
• 
  Align reference code to text for the case of using FAC with 8 short windows.
  
• 
  Correct rounding as used in edit list processing so that it is portable across platforms
  
• 
  Correct a bug in SBR for the case that the SBR crossover is lowered.
  
• 
  Correct a patching bug in SBR that aligns reference software to text.
  
• 
  Removal of un-needed delay in MPS tool (see presentation on USAC text changes)
  
• 
  Other corrections to aligns reference software to text.
  

It was the consensus of the Audio Subgroup to incorporate the proposed changes in the contribution into ISO/IEC 23003-3:2012/PDAM 2, USAC Reference Software. The Chair asked for NBs that will support the request for amendment: DE, US, DNB, CA, KR, JP.

The Chair further noted that when the JAME encoder software is revised to interoperate with the International Standard USAC decoder, NBs should cast their ballot on PDAM 2 to request that JAME be added to the USAC encoder software tree.