Abstract: A bit rate transcoding method includes: (a) receiving a motion vector of a current macroblock (MB); (b) retrieving an error count of a referenced previous MB for setting it as the error count of the current MB; (c) calculating a weight value; (d) calculating a new quantization parameter, and multiplying the same by the weight value so as to obtain a weighted new quantization parameter falling into a continuous distribution; (e) selectively using a transformation technique to transform the weighted new quantization parameter into one falling into a discrete distribution; (f) if the weighted new quantization parameter exhibits the continuous distribution, and if the weighted new quantization parameter is within a predetermined range, incrementing the error count by a predetermined value; and (g) if the weighted new quantization parameter exhibits the discrete distribution, and if the weighted new quantization parameter does not belong to a smallest quantization parameter cluster, incrementing the error count by

Abstract: A bit rate transcoding method includes: (a) receiving a motion vector of a current macroblock (MB); (b) retrieving an error count of a referenced previous MB for setting it as the error count of the current MB; (c) calculating a weight value; (d) calculating a new quantization parameter, and multiplying the same by the weight value so as to obtain a weighted new quantization parameter falling into a continuous distribution; (e) selectively using a transformation technique to transform the weighted new quantization parameter into one falling into a discrete distribution; (f) if the weighted new quantization parameter exhibits the continuous distribution, and if the weighted new quantization parameter is within a predetermined range, incrementing the error count by a predetermined value; and (g) if the weighted new quantization parameter exhibits the discrete distribution, and if the weighted new quantization parameter does not belong to a smallest quantization parameter cluster, incrementing the error count by

Abstract: A method for selectively reducing quantization levels is adapted for use in a transcoder including a variable length decoding unit. The variable length decoding unit decodes a plurality of input variable length codes into a plurality of decoded pairs, wherein each decoded pair is a run-level pair. The method includes the following steps: (a) obtaining a plurality of absolute levels arranged in an order of scan positions according to the runs and levels of the decoded pairs; (b) determining whether a saved bit number correspondingly found by reducing each absolute level exceeds a bit number threshold value such that, if yes, the respective absolute level belongs to a target set; and (c) reducing each absolute level that belongs to the target set.