| 摘要 |
<P>PROBLEM TO BE SOLVED: To properly control the amount of generated codes of an output stream toward a target bitrate without delaying output of the stream. <P>SOLUTION: A transcoder 1 calculates a reference conversion coefficient α<SB>1</SB>based on a ratio of an overall target bitrate T of a second stream and an input overall bitrate S of a first stream and calculates a variation coefficient from the overall target bitrate T of the second stream and an output average bitrate C<SB>n</SB>of the converted second stream in an Nth term. Next, the variation coefficient is added to the reference conversion coefficient α<SB>1</SB>, thereby calculating a quantization step conversion coefficient α<SB>n+1</SB>in the next N+1th term. Then, a quantization step value P of the first stream in the N+1th term is multiplied by the quantization step conversion coefficient α<SB>n+1</SB>, thereby calculating a quantization step value Q of the second stream in the N+1th term. <P>COPYRIGHT: (C)2009,JPO&INPIT |
