The Joint Collaborative Team on Video Coding (jct-vc) of itu-t wp3/16 and iso/iec jtc 1/ sc 29/ wg 11 held its tenth meeting during 11-20 July 2012 at the City Conference Centre (ccc), a k. a

JCTVC-J0428 AHG10: Mental cross-check of Selective inter-layer prediction signalling (JCTVC-J0239) [K. Sugimoto, S. Sekiguchi (Mitsubishi)] [late]
JCTVC-J0549 NAL unit types for non-reference pictures within the same temporal sub-layer [J. Samuelsson, R. Sjöberg (Ericsson), T. K. Tan, J. Takiue (NTT Docomo)] [late]

TBPSee notes for BoG report J0550.

5.12.2Random access and adaptation (12 – done)

5.12.2.1Random access point (RAP) pictures (7 – done)

JCTVC-J0107 AHG9: On RAP pictures [Y.-K. Wang, Y. Chen, R. J. Joshi, A. K. Ramasubramonian (Qualcomm)]

This document includes the following proposals related to RAP pictures (i.e., IDR, CRA and BLA pictures):

Topic 1: To include the support for handling a CRA picture as a BLA picture based on an indication through external means. Decision: Adopted.

Topic 2: To enable prediction from decodable leading pictures (non-TFD leading pictures) associated with a RAP picture by normal pictures associated with the same RAP picture, and by leading pictures associated with the next RAP picture (wherein leading pictures associated with a RAP picture are those pictures following the RAP picture in decoding order but preceding the RAP picture in output order, and normal pictures associated with a RAP picture are those pictures following a RAP picture in both decoding order and output order and preceding, in decoding order, the next RAP picture).

It was noted that contribution J0251 would eliminate non-TFD leading pictures.

Decision: The pictures that follow a RAP picture (including an IDR picture) in both decoding and output order cannot reference any leading picture.

Topic 3: To change the definition of RAP picture. No action.

Topic 4: To mandate the activation of VPS, SPS, PPS and APS at each BLA picture. No action needed.

Topic 5: To include a constraint to disallow output-order interleaving of non-TFD leading pictures with TFD pictures or pictures earlier than the same associated CRA or BLA picture in decoding order, and a constraint to disallow decoding-order interleaving of TFD pictures and following pictures associated with a RAP picture.

The spirit is that output order is as follows:

• 
  Pictures that precede the RAP in decoding order, then non-TFD leading pictures, then RAP, then following pictures
  
• 
  TFD pictures must precede non-TFD leading pictures in output order
  
• 
  But there is no relative output order constraint in regard to the order of TFD and pictures that precede the RAP in decoding order.
  

Decision: Agreed.

Regarding decoding order, all leading pictures associated with a RAP picture shall precede, in decoding order, all pictures that follow the RAP picture in output order. Decision: Agreed (consensus assessed by T. K. Tan).

Topic 6: To change related to the inference of no_output_of_prior_pics_flag equal to 1.

It was remarked that a difference in language between Annex C and clause 7 is intentional, not an error, but it was agreed that some clarification might be beneficial if the current decoding conformance language is not sufficiently clear.

The second aspect proposed was to change "first IDR or BLA picture in the bitstream" to "first picture in the bitstream" in a few places relating to no_output_of_prior_pics_flag inference. Decision: Agreed.

Topic 7: To use one more NAL unit type to differentiate TFD & TLA pictures and non-TLA TFD pictures

No action taken on this aspect.
The use of the recovery point SEI message was discussed in this context, and it was remarked that the position of the recovery point is signalled as an unsigned POC difference to be added to the POC of the current picture. This does not provide the equivalent functionality of the AVC recovery point SEI message and therefore seemed to be a bug. It was suggested to change the ue(v) encoding to se(v) with a range of –MaxPicOrderCntLsb/2 to MaxPicOrderCntLsb / 2 – 1. Decision (BF): Agreed.