International organisation for standardisation organisation internationale de normalisation

Summary of CE results compared to 3D-HTM

Topics	Proposals				Simulation Results
		Video 1		Video 2		Video PSNR / Video bit rate	Video PSNR / total bit rate	Synth PSNR / total bit rate	Enc. time	Dec. time
MV-Cand ARP with 3 weighting factors	JCT3V-G0064	-0.4%		-0.4%		-0.2%	-0.2%	-0.1%	110%	99%
MV-Cand ARP with 2 weighting factors	JCT3V-G0064	-0.5%		-0.5%		-0.2%	-0.2%	-0.1%	103%	100%
Block-level ARP	JCT3V-G0121	-0.5%		-0.7%		-0.2%	-0.2%	-0.2%	104%	102%
disable IC when ARP is enabled	JCT3V-G0072	-0.1%		-0.1%		-0.1%	-0.1%	0.0%	98%	99%
	JCT3V-G0121	-0.1%		-0.1%		-0.1%	-0.1%	0.0%	98%	100%
disable ARP when IC is enabled	JCT3V-G0072	-0.1%		-0.1%		0.0%	0.0%	0.0%	98%	99%

Block-level ARP gives the highest gain among the proposed methods. There was a question on how much each aspect of the proposal contributes, i.e., whether or not to code the residual of chroma components if the current PU is coded with ARP.

It was noted that block-level ARP would incur the worst case for 8x8, but this is not considered to be a concern since it is used in combination with sub-PU prediction.

For first aspect of G0121 (inclusion of block level ARP in merge candidate list), additional simulation results with only block-level ARP were requested. It is reported in v2 of G0121 that the gain is still 0.2%.

One expert points out that the current implementation of this first aspect of G0121 would be in contradiction with the simplification that was proposed in G0033, and G0121 would make ARP more complex on average.

Further study of the first aspect of G0121 and G0033 in a CE.

Further study second aspect of G0121 (remove CBF of chroma component) in CE was initially suggested. In a follow-up discussion after the results about using only block-level ARP were presented, it appears that the gain by this is rather negligible, which can be interpreted such that CABAC appropriately encodes the case that non-zero chroma blocks rarely occur.
JCT3V-G0095: This related contribution proposes a disparity motion vector candidate list for temporal ARP. The list includes two candidates, one is the disparity vector from NBDV process and the other is the disparity vector from DoNBDV process. The best candidate is signalled in the bitstream. The results indicate 0.l% bit rate reduction on coded and synthesized views. No action.

2.