Of itu-t sg16 wp3 and iso/iec jtc1/SC29/WG11

JCTVC-M0431 (m29385) YUV444 test sequences for screen content [Wenpeng Ding, Yunhui Shi, Baocai Yin (BJUT)] [late]

This contribution describes and introduces three YUV 4:4:4 and RGB 4:4:4 test sequences for screen content which are corresponding to the sequences in JCTVC-F741.

Three video sequences will were reported to be provided for screen content. The table below tabulates the specification of the sequences.

Sequences	Resolution	Frames	Frame rate fps	Chrome format	Bit-depth Per Sample
Doc	1280x720	500	10	4:4:4	8
Slide	1280x720	500	20	4:4:4	8
Web	1280x720	500	10	4:4:4	8

Sequences	Brief Description
Doc	A word document is being editing.
SlideShow	A slide show with all kinds of animations.
Web	Web browsing activities.

It was remarked that SlideShow is a 4:4:4 version from which the same sequence previously provided in 4:2:0 was derived.

The sequences will would reportedly be made available on the Univ. Hannover ftp site that is accessible to JCT-VC members.

The availability of the additional content was highly appreciated by the JCT-VC.

4Core experiments in Range Extensions

4.1RCE1: Inter-component decorrelation methods

4.1.1RCE1 summary and general discussion

JCTVC-M0026 RCE1: Summary report of HEVC Range Extensions Core Experiment 1 on Inter component decorrelation methods [J. Sole, K. Kawamura, J. Kim (CE coordinators)]

A summary of RCE1 on Inter component decorrelation methods for HEVC Range Extensions is reported. Four methods and combinations have been evaluated based on the range extensions common test conditions according to the CE description in JCTVC-L1121.

Test 1.1: LM Chroma

• 
  JCTVC-M0097 (JCTVC-L0240), “RCE1: The performance of extended chroma mode for non 4:2:0 format”, J. Kim (LGE)
  
• 
  Cross-check: JCTVC-M0084 (Samsung)
  

Test 1.2: Inter-plane intra coding of residual

• 
  JCTVC-M0410 (JCTVC-L0370), “RCE1: Results of in-loop color-space transformation of residual signals”, K. Kawamura, T. Yoshino, S. Naito (KDDI)
  
• 
  Cross-check: JCTVC-M0085 (Samsung)
  

Test 2.1: In-loop color-space transformation of residual

• 
  JCTVC-M0411 (JCTVC-L0371), “RCE1: Results of in-loop color-space transformation of residual signals”, K. Kawamura, T. Yoshino, S. Naito (KDDI)
  
• 
  Cross-check: Results provided by Canon (JCTVC-M0387)
  

Test 2.2: Fixed colour transforms

• 
  JCTVC-M0048 (JCTVC-L0175), “RCE1: Adaptive Color Transforms for Range Extensions”, W. Dai, M. Krishnan, P. Topiwala (FastVDO)

  Note: Only fix color transform part of the contribution is part of the CE

  
  
• 
  Cross-check: JCTVC-M0384 (Mediatek)
  

Test 3: Combination of proposals

• 
  JCTVC-M0049, “Combined Chroma Tools For Range Extensions, Test 3.3”, P. Topiwala (FastVDO) , J. Kim (LG), K. Kawamura (KDDI)
  
• 
  Cross-check: JCTVC-M0367 (Qualcomm)
  

Related non-CE contributions

• 
  JCTVC-M0116, “Non-RCE1: Multiple LM chroma modes”, C.-Y. Chen, C.-W. Hsu, C.-Y. Tsai, Y.-W. Huang, S. Lei (MediaTek)
  
• 
  JCTVC-M0230, “Non-RCE1/Non-RCE2/AHG5/AHG8: Adaptive Inter-Plane Prediction for RGB Content”, T. Nguyen, A. Khairat, D. Marpe (Fraunhofer HHI)
  

Some issues were noted:

• 
  WD text was not uploaded with most proposals
  
• 
  For Test 1.2, cross-check results do not match for few sequences in bitrates with the proponent, but match among cross-checkers.
  
• 
  For Tests 1.2 and 2.1, the proposal results were uploaded late (18/04)
  

Discussion from report:

• 
  BD-rate gains of tools reducing the colour correlation on different domain (pixel/residual) are not additive
  
  • 
    LM chroma (test 1.1) and RM (1.2) gains are not additive (3.1)
    
• 
  Largest BD-rate gains for RGB sequences are obtained with fixed colour transforms
  
• 
  One non-CE1 contribution in this meeting proposed variants on LM chroma (JCTVC-M0116) and one on the inter-plane prediction for RGB content (JCTVC-M0230).
  

Test 1.1: LM Chroma (JCTVC-M0097)

• 
  Two methods for chroma prediction which predicts chroma samples using linear combination of luma samples (LM mode)
  
  • 
    LM as was proposed in HEVC version 1, extended to non-4:2:0
    
  • 
    LM where parameter calculation is performed on a CU basis rather than per-TU
    

Test 1.2: Inter-plane intra coding of residual (JCTVC-M0410, uploaded on 4/18)

• 
  Inter-plane intra coding of residual signals (RM). In RM, correlation of residual signals between planes is reduced by using the linear model. The prediction parameter of the model is estimated at the encoder, differentially coded by predicting it from neighbouring parameters, and then signalled as additional information.
  

Test 2.1: In-loop color-space transformation of residual (JCTVC-M0411, uploaded on 4/18)

• 
  In-loop color-space transformation of residual signals for range extensions
  
• 
  This method transforms prediction error signals into those in a adaptively computed colour space. A transformation matrix is derived from pixel domain for each coding unit. The colour-space transformation is applied to prediction error of both intra and inter mode. No additional signalling is necessary.
  

Test 2.2: Fixed colour space transforms (JCTVC-M0048)

• 
  Matrix approximation of the transforms:
  
  • 
    YCbCr = [0.213, 0.715 0.072; −0.117, −0.394, 0.511; 0.511, −0.464, −0.047] (Rec. 709)
    
  • 
    YCoCg = [1/4 1/2 1/4; 1/2 0 −1/2; −1/4 1/2 −1/4]
    
  • 
    YFbFr = [5/16 3/8 5/16; −1/2 1 −1/2;1 0 −1]
    
  • 
    FbFr2 = [3/16 5/8 3/16; −1/2 1 −1/2;1 0 −1]
    
• 
  YCoCg, YFbFr and YFbFr2 are implemented with the lifting scheme
  
• 
  Test 3: Combination of methods (JCTVC-M0049)
  
  • 
    Test 1.1 + Test 1.2
    
  • 
    Test 1.1 + Test 1.2 + Test 2.2 (YFbFr2)
    
  • 
    Test 1.1 + Test 1.2 + Test 2.1 + Test 2.2
    
• 
  YCbCr
  
• 
  YFbFr2
  

Test 1.1 LM Chroma first variant: