Research On Optimization Algorithm Based On Cu Partition And The Mode Of Prediction For AVS2

With the development of video technology,the requirements of real-time transmission and other aspects is necessary,and video coding technology is rising.The core of video coding technology is the compression of video files,which can reduce the bit rate of video transmission and save the bandwidth resources of video stream.Nowadays,4K TV is gradually popularized in the market.4K resolution belongs to ultra-high definition video.Under the condition of low distortion how to reduce the bit rate and improve the feasibility of ultra-high definition video transmission is the primary problem to be solved in video coding.AVS video coding standard is a pure domestic video coding standard.At present,two generations of coding standards have been improved.The Chinese audio and video coding group is currently engaged in the development of the third generation of coding standards.The performance of avs2 is far better than the international standard h264,and is comparable to the new coding standard h265.AVS video coding technology compress the video sequence by Time redundancy and space redundancy.The related technologies include intra prediction,inter prediction,coding block division,entropy coding,loop filtering and so on.In this paper,the performance of avs2 coding is improved by optimizing the selection of intra and inter prediction mode,coding block division and the selection of intra prediction mode in the process of avs2 coding.The details are as follows:1.Selection of intra and inter prediction mode:in the AVS coding process,inter frame prediction mode will be applied to the coding block firstly.When rdcost is very small,intra frame prediction will be skipped directly.When rdcost is relatively large,intra frame prediction calculation needs to be continued.Finally,rdcost of inter frame prediction and rdcost of intra frame prediction are compared to get the most appropriate coding mode.Therefore,When most blocks are coded,both intra prediction and inter prediction operations need to be calculated,but there is only one which is used for final prediction method.This paper provides a fast algorithm,which can predict the coding block before coding and skip the intra prediction or inter prediction in advance to reduce the amount of coding calculation and improve the coding efficiency of avs2.2.Optimization of coding block division:in the process of coding,it is necessary to divide the coding image into coding blocks.In this process,it is necessary to calculate all prediction modes and get rdcost of each division mode,compare them separately,and select the optimal division mode.A large amount of calculation is caused in avs2 coding block division.In this paper,a new method is proposed By referring to the coding block division mode of this frame or the previous frame,this paper predicts the division mode of the current coding block,skips the unnecessary division mode in advance,reduces the calculation amount of coding block division,improves the coding speed,optimizes the avs2 coding block division module,and improves the avs2 coding efficiency.3.Selection of intra prediction mode:in the new generation avs2 standard,avs2 adds 33 intra prediction modes,which saves bit rate and greatly increases the coding calculation of intra prediction mode.In this paper,a fast intra prediction mode selection algorithm is proposed,which is based on the statistics of adjacent areas to predict the intra prediction mode of the coding area,,eliminate unnecessary intra prediction direction,jump out of the intra prediction direction operation in advance,improve the coding rate and the coding efficiency of avs2.