Vamsi Krishna Vegunta University of Texas, Arlington

Interim Report Color Space: Y’CrCb often termed YUV in digital video. The HVS is less sensitive to changes in color than in changes in luminance. Y'CrCb is used to separate out a luma signal (Y′) that can be stored with high resolution or transmitted at high bandwidth, and two chroma components (C B and C R ) that can be bandwidth-reduced, sub sampled, compressed, or otherwise treated separately for improved system efficiency.

Chroma Sub Sampling 24 bits/pixel16 bits/pixel12 bits/pixel Fig 1.Chroma sub sampling [1,2]

Layered Structure Sequence Picture / Frame Slice Macro block Block Fig 2. Layered structure of AVS China

Layered Structure Group of Pictures (GOP) Slice Picture Macroblock 8 pixels Block Video input Chrominance (Cb,Cr ) Luminance (Y) Fig 3. Layered structure of AVS China [3]

Picture Types Intra Pictures (I-Pictures) Predicted Pictures (P-Pictures) Interpolated Pictures (B-Pictures)

Predicted Picture (P-Picture) Prediction of a Macro block or block in the current picture may be from the most recent reference picture or from the second most recent reference picture. Fig 4. P-Pictures [4]

Predicted Picture (P-Picture) In Interlaced Format, prediction of the current field may be made from the four most recent fields. As shown, these fields may be in the current frame, most recent frame or second most recent frame. Fig 5. Interlaced P-Frame prediction [4]

Predicted Picture Modes Macroblock modes of P-prediction in AVS video : Mb Type P_Skip P_16*16 P_16*8 P_8*16 P_8*8 Table 1. Modes of P-picture [5]

Interpolated Picture (B-Picture) A Macro block or block in the current picture is predicted by the average of the macro blocks or blocks in the most recent and future P-Pictures that are selected by the motion vector. Fig 6. Interpolated Pictures [4]

Interpolated Picture (B-Picture) Fig 7. Interlaced B-Frame prediction [4]

Interpolated Picture Modes Direct Mode: Both forward and backward motion vectors of current block are derived from the motion vector of its collocated block. Symmetric Mode: Forward motion vector needs to be transmitted for each partition of current macroblock, while backward motion vector is conducted from the forward motion vector by a symmetric rule.

Interpolated Picture Modes Fig 8. Example for symmetric mode [5]

Intra Picture(I-Picture) Intra-frame prediction (intra-prediction) uses decoded information in the current frame as the reference of prediction, exploiting statistical spatial dependencies between pixels within a picture. Fig 9. Intra prediction [5]

Intra-Prediction Modes 8 × 8 Intra-prediction: (a) (b) (c) (d) (e) Fig × 8 Intra-prediction modes for Luminance component [5] (a): mode 4 : Down right (b): mode 3 : Down left (c): mode 0 : Vertical (d): mode 1 : Horizontal (e): mode 2 : DC

Intra-Prediction Modes 4 × 4 Intra- prediction: Fig × 4 Intra-prediction modes for Luminance [5] 0 : Down left 1: Vertical left 2 : Vertical 3 : Vertical right 4 : Down right 5 : Horizontal down 6 : Horizontal 7 : Horizontal up 8 : DC

Encoder Fig 12. AVS encoder [4]

Decoder Fig 13. AVS decoder [4]

Results: Profile: Jizhun Video resolution: 704 × 576 Frames per second : 30 File size: 57.4 MB QPPSNR-YMSESSIMMSSSIM3-SSIMCompression ratio : : : : :1

References 1. : Chroma sub sampling gif : Chroma sub sampling article : UTA Multimedia Processing Website : AVS Document 5. L.Yu et al, Overview of AVS-video coding standards, Signal Processing: Image Communication, Vol 24, Issue 4, Special Issue on AVS and its Application, April 2009, Pages , 6. S.Hu et al, “Efficient Implementation of Interpolation for AVS”, Image and Signal Processing, Vol 3, pp.133 – 138,May X. Jin et al, “Platform-independent MB-based AVS video standard implementation”, Signal Processing: Image Communication, Vol. 24, Issue 4, pp , April W. Gao et al, “Context-based entropy coding in AVS video coding standard”, Signal Processing: Image Communication, Vol. 24, Issue 4, pp , April Guo-An Su et al,“Low-Cost Hardware-Sharing Architecture of Fast 1-D Inverse Transforms for H.264/AVC and AVS Applications”, IEEE Trans. on Circuits and Systems II: Express Briefs, Vol. 55, Issue 12, pp.1249 – 1253, Dec

References contd W. Gao et al, “A Real-Time Full Architecture for AVS Motion Estimation”, IEEE Trans. on Consumer Electronics, Vol. 53, Issue 4, pp –1751, Nov B. Tang et al,“ AVS Encoder Performance and Complexity Analysis Based on Mobile Video Communication”, WRI International conference on Communications and Mobile Computing, CMC '09, Vol. 3, pp. 102 – 107,. 6-8 Jan X. Wang and D. Zhao, “Performance comparison of AVS and H.264/AVC video coding standards”, J. Comput. Sci. & Technol., Vol.21, No.3, pp , May X.Zhang and L. Yu, “An area-efficient VLSI architecture for AVS intra frame encoder”, Visual Communications and Image Processing 2007, Proc. of SPIE-IS & T Electronic Imaging, SPIE vol. 6508, pp , Jan. 29, Special issue on 'AVS and its Applications' Signal Processing: Image Communication, vol. 24, pp , April W.Gao, K.N. Ngan and L.Yu “Special issue on AVS and its applications: Guest editorial”, Signal Process: Image Commun, vol. 24, Issue 4, pp , April R. Schafer and T. Sikora, “Digital video coding standards and their role in video communications”, Proc. of the IEEE, vol. 83, pp , June M.Liu and Z.Wei “A fast mode decision algorithm for intra prediction in AVS-M video coding” Vol 1, International Conference on Wavelet Analysis and Pattern Recognition apos;07, Issue 2-4, pp.326 –331, Nov