International organisation for standardisation

Friday morning report:

Please find the report of this break-out group under the Plenary Discussions, Section 5.1.

Heiko Purnhagen, Dolby, presented

m17266

Provisions for MBO handling in SAOC

Jonas Engdegård Heiko Purnhagen Jürgen Herre Leonid Terentiev Cornelia Falch Oliver Hellmuth

This contribution proposed new text to clarify how MBO rendering in done in the SAOC specification. Specifically, two situations are treated

• 
  MEPG Surround is embedded in SAOC bitstream which is in turn typically embedded in the downmix bitstream. If the MPEG Surround presentation has the same number of channels as the SAOC output, the MPEG Surround is decoded and added to the SAOC output, otherwise the MPEG Surround information is discarded and only the SAOC processing is applied.
  
• 
  MPEG Surround and SAOC are independent, typically as independently embedded in the downmix bitstream. In this case, a decoder that implements only MPEG Surround can decode and present the MPEG Surround information. A decoder that implements only SAOC can decode and present the SAOC information. A decoder that implements both then both are decoded subject to the restrictions detailed in the contribution.
  

There was some discussion on the “decoding flowchart” proposed in the contribution. Henney Oh, LG, noted that it may be desirable to discard the MPEG Surround information even if its number of channels matches the number of channels of the rendering matrix output of SAOC.

The Chair recommended that interested experts discuss this proposal in a break-out and report back to the Audio subgroup.