| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance the quality of a moving picture image without increasing an amount of data to be recorded more than necessary and to ensure the remaining time for recording when recording moving picture data on a recording medium. <P>SOLUTION: A target coding rate (Tp, Tb) of a P/B picture calculated for each frame by the CBR method is correctively increased or decreased using a coding rate adjustment coefficient (Fk) determined based on the image contents, etc., of each frame. By coding according to the corrected target coding rate (T), the deterioration of an image having a large amount of information is prevented. (a) A corrective decrease (rest×(1-Fk)) of the coding rate is accumulated in a virtual accumulation management buffer, and (b) a corrective increase of the coding rate is extracted from an accumulated coding rate (Bank) accumulated in the accumulation management buffer. The upper limit (Bankmax) is set for the accumulation management buffer in advance. By restricting the corrective increase of the target coding rate (Tp, Tb) to the case that the corrective increase of the coding rate is equal to or less than the accumulated coding rate (Bank) accumulated in the accumulation management buffer, the bit rate of GOP is kept nearly constant. <P>COPYRIGHT: (C)2009,JPO&INPIT |
