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-J0465 AHG9: Mental cross-check of JCTVC-J0306 [Y.-K. Wang (Qualcomm)] [late]
JCTVC-J0569 Sub-picture Based CPB Removal Timing [S. Deshpande (Sharp), K. Kazui (Fujitsu)] [late]

J0569

When the sub-picture level CPB removal delay parameters are present, the CPB may operate at access unit level or sub-picture level. This document proposes a bitstream conformance requirement, which guarantees that the operation of sub picture based CPB operating at the sub-picture level and the CPB operating at the access unit level results in the same timing of decoding unit removal.

Additionally when the sub-picture level CPB removal delay parameters are present, this document proposes a change in the removal time of the decoding unit when low_delay_hrd_flag is 1 and t_r,n( m ) < t_af( m ).
The proposed changes are included in the attachment of this the document.

This contribution was from the authors of J0136 and J0306, and contains a merging of the proposed changes for two parts from each of the two proposals.

The desire in these proposals included aspects of "low-delay" HRD relating to matching the sub-picture DU nominal removal time and final removal time to that of the corresponding AU level in which the DUs are contained.

NOTE – The ULD HRD behaviour is not specified for purposes of testing decoder conformance – it is only a bitstream/encoder conformance specification. There are no decoder conformance tests that are affected by the ULD HRD specification.

The text that was reviewed needed some further editorial improvement.

It was suggested to define a sub-tick such that a sub-tick is t_c = t_sub*n, where n is an integer, and for the syntax to be expressed by sending the value of n. Decision: Agreed.

Between the options presented in the contribution, the "option 1a" was selected. Decision: Agreed.