Patent ID: 8208537

Claim:
A bit rate transcoding method capable of suppressing drift errors, comprising: (a) receiving a motion vector of a current macroblock of a current frame; (b) according to the motion vector, retrieving an error count of a referenced macroblock from a previous frame, and setting the error count of the referenced macroblock as an error count of the current macroblock; (c) calculating a weight value; (d) calculating a new quantization parameter using a bit rate control algorithm, and multiplying the new quantization parameter by the weight value so as to obtain a weighted new quantization parameter; and based on an evaluation of the weighted new quantization parameter, performing one of: (e) determining if the weighted new quantization parameter of one of the macroblocks is larger than a threshold value and smaller than a preset statistical value, incrementing the error count of said one of the macroblocks by a first predetermined value if affirmative, and preserving the error count of said one of the macroblocks if otherwise; and (f) determining if the weighted new quantization parameter of one of the macroblocks belongs to a smallest quantization parameter cluster, preserving the error count of said one of the macroblocks if affirmative, and incrementing the error count of said one of the macroblocks by a second predetermined value if otherwise.