Of itu-t sg16 wp3 and iso/iec jtc1/SC29/WG11

JCTVC-O0166 MV-HEVC/SHVC HLS: On non-HEVC base layer [M. M. Hannuksela (Nokia)]

The contribution discusses having a bitstream format that encapsulates a non-HEVC-coded base layer and MV-HEVC/SHVC enhancement layers and asserts that no such need is envisioned. The contribution proposes to use external means to provide decoded base-layer pictures for the enhancement layer decoding process. The contribution proposes to provide certain DPB-related properties of non-HEVC-coded base-layer pictures either through external means or using a specific NAL unit within the HEVC bitstream.

As the changes are asserted to be substantial and may require verification by both expert review and software implementation, the contribution has been submitted for discussion rather than for immediate action.

Properties needed for the base layer pictures are suggested to include the following:

• 
  NoOutputOfPriorPicsFlag
  
• 
  PicOutputFlag
  
• 
  PicOrderCntVal
  
• 
  Reference picture set
  

Syntax is proposed to assign these properties to the base layer pictures. It was remarked that these properties can be derived from the AVC bitstream itself as well.

It is proposed for the type of non-HEVC base layer to not be specified in the HEVC spec, and for the profile to be an "enhancement layer only" profile, with the base layer capability established by external means.

It was remarked that an AVC prefix NAL unit might suffice to assign temporal sub-layer ID and PicOutputFlag and the other aspects can be derived from the AVC NAL units.

It was remarked that the reference picture set information might not be needed, as inter-layer referencing is only within the same access unit and the base layer decoder could be considered responsible for managing its own memory requirements.

The CPB would be just for the enhancement layer.