Context-adaptive coded block pattern coding for H.264/AVC

For coding of quantized transform coefficients, a coded block pattern (CBP) is a key syntax element to represent the existence of coefficients in a macroblock efficiently. In H.264/AVC, the CBP is coded by using a fixed variable length coding table, called Exp-Golomb codes. However, since the CBP is highly affected by the change of quantization parameter (QP), in this paper, we show the CBP distributions according to the change of QP and propose an context-adaptive CBP coding method. The proposed scheme selects the coding table adaptively based on the context of neighbors’ CBP. Experimental results show that the proposed scheme reduces average 1.15% in total bit rate and 12.54% in CBP bit rate compared to the anchor, H.264/AVC.