International organisation for standardisation organisation internationale de normalisation

5.13.2Adaptation parameter sets and multi-slice operations

5.13.2.1Partial update

The proposals in this category were reviewed with the assistance of summary information prepared by Y.-K. Wang, and recorded as follows.

	Method summary	Cons
H0069	Linked APSs – conditionally referencing to another APS	Cross-APS dependency – error resilience problem Not easy to specify
H0070	Conditional replacement	Cross-APS dependency – error resilience problem Inefficiency when to-be-overwritten content may be re-usable
H0119	Conditionally referencing to another APS for QM parameters	Partly solves the partial update problem Cross-APS dependency – error resilience problem
H0255 - 1	Multiple APS IDs in SH	Multiple APS IDs in SH SH syntax not future-proof (syntax change needed when in the future stuff goes into APS )
H0255 - 2	Allowing explicitly signaling different types of APS parameters in SH that can override the one in APS	Complex SH syntax Inefficiency when content added to SH may be re-usable
H0381	A “copy” flag for each type of APS params, which allows copying that type of APS parameters from another conditionally referenced APS	Cross-APS dependency – error resilience problem Complex APS syntax
H0505 - 1	Each APS NAL unit contains only one type of APS params; Grouping of multiple APS IDs and PPS ID in GPS; References only GPS ID in SH	Each APS NAL unit contains only one type of APS params Needs GPS
H0505 - 2	Similar as above, but each APS NAL unit may contain multiple types of APS params	Needs GPS

After discussion at the summary level, it was suggested to focus on H0069 (which is roughly the BoG output from the last meeting), H0381, and H0505. It was remarked by the contributor of H0119 that its intent was consistent with H0381, so that it might not need to be considered separately.

H0381 seems like a straightforward generalization of H0069, while H0505 seems like a larger degree of restructuring.

For the GPS approach in H0505, the PPS ID is moved from the SH to the GPS. Possibly the SPS ID is also moved from the PPS to the GPS. It was commented that, hypothetically, the PPS ID could be put into the APS when otherwise using H0069 or H0381 as well.

It was remarked that the text for H0381 was inadequate, as the semantics are missing.

In initial discussions, it seemed that we were closest to agreeing on H0069, but further discussed it later in the meeting.

There was later discussion of the use of linked lists versus conditional-refresh for updates.

Some participants advocated a linked list approach while others advocated a conditional-replacement-based approach. There was some confusion over what was intended in some of the proposals. The intent for E0381 seemed to be unclear to the group. (Another contribution H0070 and prior contribution E309 was mentioned as a use of the conditional-replacement-based approach.)

It was suggested to allow self-referencing updates, i.e. an update referencing the same APS ID, which would be a conditional-replacement-based update (resolved at the time of receipt of the APS NAL unit), while an update referencing a different APS ID would act as a pointer (resolved at activation time) rather than as a conditional-replacement-replace update (resolved at the time of receipt of the APS NAL unit).

It was remarked that the GPS concept may be simpler, in that it avoids the linked-list structuring and the possibility of misinterpretation of the timing of the copying, which could become confusing.

Later, new versions of H0069 were submitted (-v3 and –v4).

This included:

• 
  Parameter set referencing (content established at the beginning of each picture or at the beginning of each slice)
  
• 
  Conditional replacement (with the same parameter set ID)
  
• 
  Invalidation (with the same parameter set ID)
  

The same APS ID would not be allowed to appear more than once as the list linking is followed.

It was remarked that something like the GPS concept (i.e. a list of pointers) might seem simpler than a linked list.

Further study was needed.

5.13.2.1.1.1.1.1.1JCTVC-H0069 APS partial update through referencing [S. Wenger, J. Boyce (Vidyo), Ming Li, Ping Wu (ZTE)]

This contribution proposed linked APSs.

5.13.2.1.1.1.1.1.2JCTVC-H0070 APS partial update through conditional replacement [S. Wenger, J. Boyce (Vidyo)]

This contribution was not suggested to be emphasized for consideration.

It uses over-writing rather than linking.

5.13.2.1.1.1.1.1.3JCTVC-H0119 Non-CE4 Subtest2: Extension of Adaptation Parameter Sets syntax for scaling list matrix [J. Tanaka, Y. Morigami, T. Suzuki (Sony)]
5.13.2.1.1.1.1.1.4JCTVC-H0255 On partial updating of APS parameters [A. Minezawa, K. Sugimoto, S. Sekiguchi (Mitsubishi)]
5.13.2.1.1.1.1.1.5JCTVC-H0381 AHG15: Partial APS update [V. Drugeon, S. Esenlik, M. Narroschke, T. Wedi, V. Wahadaniah (Panasonic)]
5.13.2.1.1.1.1.1.6JCTVC-H0505 On APS partial update [Y. -K. Wang, Y. Chen, G. Van der Auwera (Qualcomm)]