Improved context-adaptive arithmetic coding in H.264/AVC

An improved Context-based Adaptive Binary Arithmetic Coding (CABAC) is proposed for applications in video compression. The improved CABAC is characterized by higher coding efficiency as compared to that of the original CABAC as standardized in ISO MPEG-4 AVC (Advanced Video Coding) and ITU-T H.264. In the proposal, the increase of compression ratio is obtained by application of more exact data statistics estimation based on well-known data modeling algorithm: Context-Tree Weighting (CTW). The improved CABAC codec has been tested in the framework of AVC video codec. The extensive experiments show that application of the modified AVC yields 1.2% - 5.4% bitrate reduction. Computational effort of the modified AVC decoder is about 5-10% and 15-25% greater relative to the original AVC decoder for SD and HD video sequences respectively.