Organisation internationale de normalisation

BoGs

13.0.0.1.1.1.1.1.341JCTVC-S0292 BoG report on CE6 improvements of palette mode [R. Cohen, Y.-W. Huang]

See section 5.1.6.

13.0.0.1.1.1.1.1.342JCTVC-S0294 BoG report on complexity assessment of IBC block vector coding [C. Pang, S. Liu]

See section 4.2.1.

13.0.0.1.1.1.1.1.343JCTVC-S0304 BoG report on Adaptive Colour Transform (ACT) J. Boyce

See section 5.1.12.

13.0.0.1.1.1.1.1.344JCTVC-S0308 BoG report on Intra String Copy (CE10) [Y. Chen]

See section 4.10.1.

4. Summary of normative decisions

The following is a summary of the normative decisions made at the meeting for the draft screen content coding extensions:

• 
  Adaptive colour transform
  
  • 
    JCTVC-S0086 – Syntax made dependent on whether chroma pred mode is derived the luma prediction mode, and move the ACT enabling flag to PPS (cleanup)
    
  • 
    JCTVC-S0086 / JCTVC-S0140 / JCTVC-S0144 – Clipping of final adjusted QP value to not be negative (bug fix)
    
  • 
    JCTVC-S0086 / JCTVC-S0180 – Shift to align colour components that have different bit depths, and disallow ACT for trans-quant-bypass CUs when the colour component bit depths differ (cleanup)
    
  • 
    JCTVC-S0086 / JCTVC-S0254 – Use YCoCg-R for both lossy and lossless coding (cleanup)
    
• 
  Intra block copy
  
  • 
    JCTVC-S0070 / JCTVC-S0088 / JCTVC-S0220– Constrained referencing area (regardless of whether bitstream uses WPP) to enable WPP decoding operation (bug fix)
    
• 
  Pallete
  
  • 
    JCTVC-S0025 / JCTVC-S0037 / JCTVC-S0189 / CE5 – Maximum palette size and maximum palette predictor size sent in SPS as ue(v) and add profile constraint to disallow values greater than 31 and 64, respectively (cleanup)
    
  • 
    JCTVC-S0026 / JCTVC-S0163 / JCTVC-S0038 / JCTVC-S0269 / CE6 – Modified binarization for run coding (coding efficiency ~1.5% for AI TGM)
    
  • 
    JCTVC-S0088 / JCTVC-S0141 – Palette prediction for WPP made similar to CABAC context resetting (cleanup and minor coding efficiency improvement ~0.6% for AI TGM)
    
  • 
    JCTVC-S0153 / CE6 – Modified coding of palette table relative to palette predictor (cleanup)
    
  • 
    JCTVC-S0043 – Delta QP for palette escape coded pixels (cleanup)
    
  • 
    JCTVC-S0105 / JCTVC-S0110 / JCTVC-S0173 – When the palette size is zero, infer that all pixels are escape coded (cleanup)
    
  • 
    JCTVC-S0096 – Disable deblocking within palette coded regions (cleanup)
    
  • 
    JCTVC-S0150 / JCTVC-S0181 / JCTVC-S0258 – Allow escape indices to be referred to by the copy above mode, and allow run coding with escape coded pixels (cleanup)
    
• 
  Inter
  
  • 
    JCTVC-S0085 – Adaptive MV resolution (coding efficiency ~3% for TGM RA/LB)
    
• 
  Intra
  
  • 
    JCTVC-S0102 / JCTVC-S0309 / CE9 – SPS-level disabling of intra boundary filtering (cleanup / coding efficiency ~1% for AI mixed content)
    
• 
  Cross-component prediction
  
  • 
    JCTVC-S0003 – Constrain the input to cross-component prediction to a 16 bit range when the extended precision inverse transform is disabled (corrigendum bug fix)
    

Note that the last item also affects the fidelity range extensions already standardized in HEVC version 2.

For further detail, see notes in other sections. The above list is only provided as a summary.

7.