Variable bit rate coding using the BFOS algorithm

摘要

A variable bit rate video (VBR) coding method includes the steps of (a) dividing an entire sequence of moving pictures into N blocks, (b) determining a quantizer scale group having M elements, each element being applied to MPEG I, P, and B pictures, (c) quantizing the N blocks divided in step (a) by the M quantizer scales determined in step (b), (d) producing M×N bit rate-distortion pairs as a result of step (c), (e) assigning optimal bits to the N blocks divided in step (a) by applying the BFOS algorithm to the M×N bit rate-distortion pairs produced in step (d), and (f) variable bit rate-coding the entire sequence of moving pictures by using the optimal number of bits assigned to each block in step (e). Therefore, the VBR video coding method can minimize distortion resulting from coding by variably assigning a given total number of bits to each block of an entire sequence of moving pictures, and allocation of more bits to a very significant portion of a moving picture leads to a better, more uniform picture quality with a lower average bit rate than in constant bit rate coding.