PhD Comprehensive exam proposal Planned Exam date May 6 2010 The University of Texas at Arlington 2010 Supervising Professor Dr K R Rao LOW COMPLEXITY AVS CHINA PART II VIDEO CODEC DESIGN USING DATAMINING TECHNIQUES by Jennie G Abraham ABSTRACT This research proposes to reduce the computational complexity of AVS China Part II video codec by reducing the overall computations involved in intra and inter mode decisions The attempt is to accomplish this by using decision trees which is one of the data mining techniques for classification A number of attributes for each macroblock MB is extracted to be given as input to the decision tree algorithm The various attributes give sufficient amount of statistical information of each MB and thus should allow the classification of the MBs such that they are mapped to the appropriate mode which would have been assigned to them by the codec This classification would be done offline and the results from the decision tree can be written as if else statements in C This piece of code would then replace the complex mode decision algorithm in the video codec Extensive offline data mining should then enable for determining a decision tree that would work for all videos This would result in a low complexity video codec which is modified once and for all times Expected outcome of the research also includes video quality nearly equivalent to the original video codec without any decrease in the compression ratio TABLE OF CONTENTS 1 INTRODUCTION 1 1 Scope of a standard 2 AVS CHINA PART II 2 1 Profiles and Levels 2 1 1 AVS Video Jizhun profile base profile 2 1 2 AVS video Jiben profile basic profile 2 1 3 AVS Shenzhan profile extended profile 2 1 4 AVS Jiaqiang profile enhanced profile 2 2 Data Formats used in AVS 2 2 1 Layered Structure 2 3 System Architecture 3 CODING TOOLS IN AVS CHINA VIDEO Part 2 3 1 8x8 Intra Predictions 3 2 Inter Prediction 3 2 1 P Prediction 3 2 2 Bi prediction 3 2 3 Interpolation 3 3 Transform and Quantization 3 3 1 8x8 integer cosine transform ICT 3 4 In loop deblocking filter 3 5 2D VLC Variable Length Coding 4 DATA MINING AND MACHINE LEARNING FOR MODE DECISION TREES 4 1 LOW COMPLEXITY MODE DECISION ALGORITHM 5 SUMMARY 6 REFERENCES LIST OF ILLUSTRATIONS Fig 1 1 An example of a multimedia ecosystem Fig 1 2 History of audio video coding standards Fig 1 3 Video encoding decoding process Fig 1 4 shows the encoding and decoding processes of a general video Fig 2 1 Color formats of input sequence Fig 2 2 A frame divided into two fields Fig 2 3 Layered data structure Fig 2 4 16x16 MB in 4 2 0 format Fig 2 5 Normal slice structure and flexible slice set in AVS video Fig 2 6 Macroblock partitioning for inter prediction Fig 2 7 AVS video coding framework Fig 2 8 Intra prediction Fig 2 9 Inter prediction in a block based video codec Fig 2 10 Four types of block sizes supported in AVS P2 Fig 2 11 Zig zag scanning order and new scanning order Fig 2 12 Reconstruction of MB image from residual MB and MB predicted using motion vectors Fig 3 1 Neighboring pixels in luminance intra prediction Fig 3 2 Five luminance intra prediction modes Fig 3 3 Symmetric mode of AVS Part 2 Fig 3 4 Position of integer pixels 1 2 pixels and 1 4 pixels Fig 3 5 Maximum of two reference pictures in AVS video Fig 3 6 Quantization of the transformed coefficients of the image block Fig 3 7 Six pixels involved in de blocking filtering Fig 4 1 Example of a decision tree generated by WEKA Fig 4 2 Extracting features of MB adjacent to current block LIST OF TABLES Table 2 1 Different parts of AVS standard Table 2 2 Application based profiles of AVS Table 2 3 Features of the four profiles in AVS China video codec LIST OF ACRONYMS AVS Audio Video Standard AVS M Audio Video Standard for mobile B Frame Interpolated Frame CAVLC Context Adaptive Variable Length Coding CBP Coded Block Pattern CIF Common Intermediate Format DPB Decoded Picture Buffer DVD Digital Versatile Disc EOB End of Block HD High Definition HHR Horizontal High Resolution ICT Integer Cosine Transform IDR Instantaneous Decoding Refresh I Frame Intra Frame ITU T International Telecommunication Union MB Macroblocks MBPAFF Macro Block Pair Adaptive Field Frame MPEG Moving Picture Experts Group PAFF Picture Adaptive Field Frame P Frame Predicted Frame QCIF Quarter Common Intermediate Format QP Quantization Parameter RD Rate Distortion SAD Sum of Absolute Differences SD Standard Definition TV Television VLC Variable Length Coding 1 INTRODUCTION Broadcast television and home entertainment have been revolutionized by the advent of digital TV and DVD video These applications and many more are made possible by the standardization of video compression technology Video compression or video coding is an essential technology for applications such as digital television DVD Video mobile TV videoconferencing and internet video streaming 1 Fig 1 1 shows the example of a home media ecosystem Figure 1 1 An example of a home media ecosystem In today s world a seamless integration of various standards is highly desirable The history of various audio video coding standards as they emerged over the years can be seen in Figure 1 2 1stGENERATION 2ndGENERATION Figure 1 2 History of audio video coding standards 21 Standardizing video compression makes it possible for products from different manufacturers e g encoders decoders and storage media to inter operate An encoder converts video into a compressed format and a decoder converts compressed video back into an uncompressed format 1 1 Scope of a standard The process of converting a digital video into a format that takes up less capacity when it is stored or transmitted is defined by each industry standard for video compression These standards define the format syntax for compressed video bitstream and a method for decoding this syntax to produce a displayable video sequence The standard document does not actually specify how to encode compress digital video this is left to the manufacturer of a video encoder but in practice the encoder is likely to mirror the steps of the decoding process VIDEO ENCODER Video Source Predict Transform Quantize Encode Bitstream as defined by the standard VIDEO DECODER Video Output Reconstruct Inverse transform InverseQuantization Decode Scope of the standard Figure 1 3 Video encoding decoding process Figure 1 3 shows the encoding and decoding processes of a general video compression scheme and highlights the parts specified by the standard 2 AVS CHINA PART
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