A coding tree unit can be subdivided into square regions as coding units (CUs) using a structure. Each CU is predicted using inter or intra prediction and transformed using one or more transform units. Fig 10: Picture, Slice, Coding Tree Unit (CTU), Coding Unit (CU) [19] 6.4.2 Prediction [1]: Frames of video are coded using intra or inter prediction: Intra prediction: Each PU is predicted from neighboring image data in the same picture, using DC prediction (an average value for the PU), planar prediction (fitting a plane surface to the PU) or directional prediction (extrapolating from neighboring data). Inter prediction: Each PU is predicted from image data in one or two reference pictures (before or after the current picture in display order), using motion compensated prediction. Fig 11: Modes and angular intra prediction directions in HEVC [1] 6.4.3 Transform and Quantization [19] : Any residual data remaining after prediction is transformed using a block transform based on the Discrete Cosine Transform (DCT) [13] or Discrete Sine Transform (DST). One or more block transforms of size 32x32, 16x16, 8x8 and 4x4 are applied to residual data in each CU. Fig 12: CTU showing of transform (TU) sizes [19] Then transformed data is quantized. 6.4.4 Entropy coding: A HEVC bit stream consists of quantized transform coefficients, prediction information such as prediction modes and motion vectors, partitioning information and other header data. All of these elements are encoded using Context Adaptive Binary Arithmetic Coding (CABAC) [14] similar to H.264/AVC. 7. VP9 [3] [4]: : 7.1 Introduction VP9 is an open and royalty free video compression standard being developed by Google. VP9 had earlier development names of Next Generation Open Video (NGOV) and VP-Next. VP9 is a successor to VP8. Development of VP9 started in Q3 2011. One of the goals of VP9 is to reduce the bit rate by 50% compared to VP8 while having the same video quality [22]. Also VP9 aims
A coding tree unit can be subdivided into square regions as coding units (CUs) using a structure. Each CU is predicted using inter or intra prediction and transformed using one or more transform units. Fig 10: Picture, Slice, Coding Tree Unit (CTU), Coding Unit (CU) [19] 6.4.2 Prediction [1]: Frames of video are coded using intra or inter prediction: Intra prediction: Each PU is predicted from neighboring image data in the same picture, using DC prediction (an average value for the PU), planar prediction (fitting a plane surface to the PU) or directional prediction (extrapolating from neighboring data). Inter prediction: Each PU is predicted from image data in one or two reference pictures (before or after the current picture in display order), using motion compensated prediction. Fig 11: Modes and angular intra prediction directions in HEVC [1] 6.4.3 Transform and Quantization [19] : Any residual data remaining after prediction is transformed using a block transform based on the Discrete Cosine Transform (DCT) [13] or Discrete Sine Transform (DST). One or more block transforms of size 32x32, 16x16, 8x8 and 4x4 are applied to residual data in each CU. Fig 12: CTU showing of transform (TU) sizes [19] Then transformed data is quantized. 6.4.4 Entropy coding: A HEVC bit stream consists of quantized transform coefficients, prediction information such as prediction modes and motion vectors, partitioning information and other header data. All of these elements are encoded using Context Adaptive Binary Arithmetic Coding (CABAC) [14] similar to H.264/AVC. 7. VP9 [3] [4]: 7.1 Introduction : VP9 is an open and royalty free video compression standard being developed by Google. VP9 had earlier development names of Next Generation Open Video (NGOV) and VP-Next. VP9 is a successor to VP8. Development of VP9 started in Q3 2011. One of the goals of VP9 is to reduce the bit rate by 50% compared to VP8 while having the same video quality [22]. Also VP9 aims