International organisation for standardisation organisation internationale de normalisation

MV/DV candidates (6)

(Chaired by A. Vetro)

14.1.1.1.1.1.1.1.144JCT3V-G0067 Availability checking of temporal inter-view MV candidate and VSP candidate [J. An, Y.-W. Chen, K. Zhang, J.-L. Lin, S. Lei (MediaTek)]

This contribution fixes a problem of using an unavailable reference view. It is proposed to check the availability of temporal inter-view MV candidate and VSP candidate according to the existence of inter-view reference picture. When there is no inter-view picture in the current reference lists, the temporal inter-view MV candidate and VSP candidate should not be inserted into the merge candidate list.

The problem will happen when there is no inter-view reference in the merge list construction.

As an alternative, it was suggested to disable NBDV and VSP at the slice level when no inter-view reference is available, but this signalling is not currently supported.

One expert expressed support for this proposal. WD text was reviewed, and was considered straightforward.

Decision(BF): Adopt.

14.1.1.1.1.1.1.1.145JCT3V-G0080 Improvement on Do-NBDV derivation [X. Chen, Y. Lin, X. Zheng, J. Zheng, (Hisilicon)]

In current 3D-HEVC, Do-NBDV uses the maximum among four corners of the depth samples to extract a disparity vector from the virtual depth block. There are two contributions for Do-NBDV:

1, The proposed method uses the maximum among two or three corners of the depth samples to extract a disparity vector from the virtual depth block. The experimental results reportedly show that the proposed method (three corners) has minor coding efficiency gain or no overall coding efficiency loss (two corners), and the computational complexity and memory access of depth samples are reduced.

2, It is proposed to recalculate corners position of the depth samples from the virtual depth block and select the corner which has maximum depth value after maximum among corners of the depth samples from the virtual depth block. The experimental results reportedly show that the proposed method has 0.04 coding efficiency gain.

In the current design, the disparity vector is derived using four corners. It is suggested that two or three corners is sufficient.

It was remarked that there is no problem with the current design and it is not desirable to make small and unjustified changes. No action.

14.1.1.1.1.1.1.1.146JCT3V-G0183 Crosscheck of Improvement on Do-NBDV derivation (JCT3V-G0080) [T. Ikai (Sharp)] [late]

14.1.1.1.1.1.1.1.147JCT3V-G0081 Improvement on NBDV derivation [X. Chen, X. Zheng, Y. Lin, J. Zheng, (Hisilicon)]

In HTM 9.0r1, NBDV is calculated by candidates of temporal, special, MCP or Default. We build the relationship between NBDV and Do-NBDV in certain condition. The experimental results reportedly show that build relationship between NBDV and Do-NBDV can achieve 0.05% BD-rate saving for overall coded and synthesized views compared to HTM-9.0r1.

This proposal aims to improve coding efficiency, but only gives 0.05% gain which is considered negligible. No action.

14.1.1.1.1.1.1.1.148JCT3V-G0215 Crosscheck on Improvement on NBDV derivation (JCT3V-G0081) [H. Liu (Qualcomm)] [late]

14.1.1.1.1.1.1.1.149JCT3V-G0096 Bug-fix on merging candidate list construction [G. Bang (ETRI), Y.S. Heo, G.H.Park (KHU), G.S. Lee, N.H.Hur (ETRI)]

This report presents a bug-fix on merging candidate list construction. In current 3D-HEVC, the maximum size of merging candidate list is generally 6 (5 + NumExtraMergeCand) for dependent view or depth. Therefore, in order to prevent buffer-overflow, checking current size of the list is necessary in decision of inserting candidates whose priority are lower than IvDC. However, as shown in Table 1, current WD does not check the size of the list when inserting VSP, A0, and B2 to the list.

This contribution identifies a mismatch between the text and software. The WD text has been checked by the editor and is agreed.

Decision (BF): Adopt.

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