Patent ID: 6028896
Filing Date: 2000-02-22
Classification: H04N

Abstract:
A method for controlling the data bit rate of a differential pulse code modulation/discrete cosine transform (DPCM/DCT) video encoder, comprising the steps of:determining an initial bit allocation amount for every group of pictures (GOP) of an input video;allocating bits for every picture of each GOP;allocating bits for every macroblock of each picture;determining a quantizer step parameter based on the bit allocation amount,wherein the quantizer step parameter for every macroblock is determined to be proportional to a value obtained after subtracting the accumulated amount of bits allocated for up to the macroblock from the accumulated amount of bits generated for up to the macroblock, andwherein the quantizer step parameter for every macroblock is determined using the following equation:d.sub.j =d.sub.o +.SIGMA.B.sub.j -.SIGMA.TMB.sub.jwhere,""d.sub.j "" represents a quantizer step parameter of a j-th macroblock;""d.sub.o "" represents an initial value of ""d.sub.j "";"".SIGMA.B.sub.j "" represents the accumulated amount of bits generated for up to the j-th macroblock; and"".SIGMA.TMB.sub.j "" represents the accumulated amount of bits allocated for up to the j-th macroblock; anddetermining a quantizer step proportional to the determined quantizer step parameter.