International organisation for standardisation organisation internationale de normalisation

Coding results of G0078 Method1 and G0066

	Video 1	Video 2	Video/video BR	Video/total BR	Synthesized/total BR	Enc time	Dec time
G0078-Method1	-0.20%	-0.13%	-0.09%	-0.09%	-0.05%	99.63%	100.61%
G0066	-0.24%	-0.20%	-0.09%	-0.08%	-0.05%	96.5%	94.3%

Coding results of G0078 Method1 + Method2

G0078	Video 1	Video 2	Video/video BR	Video/total BR	Synthesized/total BR	Enc time	Dec time
Method1+Method2	-0.28%	-0.21%	-0.13%	-0.13%	-0.08%	99.7%	98.9%

G0078 method 1 requires 2 additional comparisons, whereas in worst case G0066 could require six additional comparisons in the merge list construction, whereas it is claimed to possibly simplify the pruning process in the case of IC.

G0078 method 2 only gives very little gain, while further increasing the complexity.

Further investigation of G0034, G0099, G0104 (simplifying merging) and G0078 method 1 and G0066 (making merging a little bit more complex with small benefit in compression) in CE. The result of the CE shall be accompanied by a decent worst case complexity analysis.
d) Others

JCT3V-G0082 proposes to limit the range of NBDV according to the possible disparity range between the current texture view and the reference view. Two different methods are proposed. Both of the two methods can limit the range NBDV into a rectangle area, which makes the possible accessed area in reference view be much smaller than with current design.

Coding results of G0082

	Video 1	Video 2	Video/video BR	Video/total BR	Synthesized/total BR	Enc time	Dec time
Method1	-0.09%	-0.11%	-0.03%	-0.03%	-0.03%	100.4%	98.2%
Method2	-0.14%	-0.10%	-0.03%	-0.03%	-0.04%	102.4%	98.0%

It is claimed that the approach limits the maximum cache size necessary. Data are given based on the set of test sequences, which may however not cover the possible worst case, since in principle we currently do not have any limitation on the motion vector. Another possibility to achieve this could be a limitation on the allowable range of inter-view motion vectors (as bitstream constraint within a given profile/level). Further study required on these issues.
JCT3V-G0128 [Qualcomm& PKU] CE3 related: Motion storage optimization in 3D-HEVC

In current 3D-HEVC, motion compression is achieved by two steps: compression to 8x8 level after each picture is decoded, and compression to 16x16 level after the whole access unit is decoded. In this document, it is proposed that the 3D-HEVC design should be aligned with the HEVC design for inside access unit motion storage optimization and the current 8x8 motion compression should be removed.

Coding results of G0128

	Video 1	Video 2	Video/video BR	Video/total BR	Synthesized/total BR	Enc time	Dec time
G0128	-0.22%	-0.16%	-0.05%	-0.04%	-0.06%	102.2%	99.9%

The proposal is to use uncompressed motion parameters within the same access unit. It is claimed that the amount of memory is not increased. WD text is not available. Further information is necessary.

In the discussion, it is emphasized that if the amount of memory is kept the same, the memory access mechanism is probably having some irregular content-dependent condition, dependent on 4x8/8x4/8x8 and uni-/bi prediction.

An update of the contribution is announced including WD text and more clarification about the memory consumption. This was further discussed 01-14 PM.

With a sophisticated implementation, it is true that no additional memory is needed to store the motion parameters. However, additional complexity would be needed 1) for determining the meaning of the two MP sets stored per 8x8 block depending on uni/bi prediction mode 2) for the interpretation of list 0/1 signalling. Several experts expressed the concern that instead of that, hardware implementations might rather prefer storing uncompressed motion parameters on a 4x4 grid.

No action.
JCT3V-G0149 proposes to utilize depth map for sub-PU level inter-view motion prediction (SPIVMP). While the current SPIVMP utilizes single disparity vector to derive motion parameters for all sub-PUs in single CU, the proposed method derives disparity vector for each sub-PU from depth map as view synthesis prediction does.