High-efficiency video coding: tools and complexity Oct

HEVC Highlights – Latest video coding standard developed by the JCTVC – 50% bit rate reduction compared with the H.264/AVC at same visual quality – HEVC decoder complexity is similar to the H.264/AVC decoder, but encoder is way more complex than the H.264/AVC encoder. – HEVC extensions are under developing

Hybrid Motion-compensation & Transform Coding

What’s new? Recursive coding tree structure (64x64 -> 4x4) Advanced intra prediction DCT based interpolation filter Advanced inter prediction Discrete Since Transform Scanning Sample adaptive offset

Recursive Tree Structure H.264/AVC – 16x16 macroblock – 16x16, …, 4x4 prediction block – 8x8 & 4x4 transform block HEVC – 64x64, …, 4x4 recursive coding unit (CU) – 64x64, …, 4x4 recursive prediction unit (PU) – 32x32, …, 4x4 recursive transform unit (TU)

If we restricted LCU < 64x64

Intra Prediction H.264/AVC – Up to 9 modes HEVC – Up to 35 modes – Intra smoothing [1,2,1]/4

Interpolation H.264/AVC – 6-tap Wiener for ½ pixel – Bilinear for ¼ pixel HEVC – 8-tap DCT-IF for ½ pixel – 7-tap DCT-IF for ¼ pixel

Inter Prediction H.264/AVC – Median motion from neighboring blocks HEVC – Spatial motion vector prediction – Temporal motion vector prediction

Discrete Since Transform Intra 4x4 only – 1% BD-Rate gain

Scanning H.264/AVC – Zigzag HEVC (zigzag is the history!) – Diagonal up-right – Horizontal – Vertical

Sample adaptive offset (SAO) SAO

History of the tool development

And more …. mid-2004 H.264/AVC High Profile Early-2005, VCEG Key Technology Area (KTA) , MPEG Call for Evidence Jan. 2010, Joint CfP April 2010, 1 st JCT-VC meeting, TMuC Oct. 2010, 3 rd JCT-VC meeting, WD1 July 2012, 10 th JCT-VC meeting, DIS Jan. 2013, 12 th JCT-VC meeting, FDIS

Performances of the HEVC (1) Objectively – IBBP – IPPP

Performances of the HEVC (1) Subjectively

Complexity Analysis NTT DoCoMo Real-Time HEVC Decoder

HEVC Related R&D Fast Mode Decision Rate Control HEVC Perceptual Quality Model Software Implementation – ARM – ARM + GPU Hardware implementation

HEVC Scalability CfP: July 2012 Stockholm Meeting – Base layer could be compatible with HEVC, H.264/AVC, MPEG-2 – Enhancement layer can use new developed tools First JCT-VC meeting on scalability: Oct Shanghai Meeting – Select the base software to develop the HEVC based scalability – FDIS of HEVC scalability: Jan. 2014

References [1] G. J. Sullivan, J.-R. Ohm, W.-J. Han, and T. Wiegand, "Overview of the High Efficiency Video Coding (HEVC) Standard," IEEE Transactions on Circuits and Systems for Video Technology, vol. 22, December [2] J.-R. Ohm, G. J. Sullivan, H. Schwarz, T. K. Tan, and T. Wiegand, "Comparison of the Coding Efficiency of Video Coding Standards – Including High Efficiency Video Coding (HEVC)," IEEE Transactions on Circuits and Systems for Video Technology, vol.22,December [3] F. Bossen, B. Bross, K. Sühring, and D. Flynn, "HEVC Complexity and Implementation Analysis," IEEE Transactions on Circuits and Systems for Video Technology, vol.22, December 2012.