Patent ID: 7983337

Claim:
A moving picture coding device configured to perform a motion-compensated prediction for moving picture data in macroblocks, to apply a discrete cosine transform and a quantization to a prediction error obtained by the motion-compensated prediction to obtain a quantization step size, and to apply variable-length-coding to the quantization step size together with a motion vector to be obtained by the motion compensated prediction, comprising: a coding controller configured to control coding modes of target macroblocks for the variable-length-coding in response to picture types respectively, wherein the coding controller comprises: a quantization step size determining module configured to determine whether the quantization step size is equal or greater than a threshold when the picture type of the target macroblocks is a Bi-directional (B) picture which is not a reference frame for other frames; a frame prediction mode processor configured to perform motion detection only by frame prediction if the quantization step size is equal to or greater than the threshold; a conventional mode processor configured to perform the motion detection after a conventional frame/field prediction determination if the quantization step size is smaller than the threshold; and a skip determination controller configured to skip a coding of the target macroblocks under predetermined conditions after motion detection by the frame prediction mode processor or the conventional mode processor.