Abstract
A method and an apparatus for generating a coded block pattern for highpass coefficients are provided. The method includes receiving a quantized highpass coefficient (HP), wherein the HP includes a macroblock data; dividing the macroblock into a plurality of blocks; performing lapped transform (LT) operations of two stages on the said block data, concurrently calculating a plurality of coded block patterns of the blocks corresponding to all possible HP prediction directions; performing a calculation to obtain selection information of the HP prediction directions according to lowpass coefficients (LPs) generated through LT operations of the two stages; selecting a corresponding coded block pattern among the said coded block patterns according to the above-mentioned selection information of the HP prediction directions and outputting the selected coded block pattern.