| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a coder using arithmetic coding which performs approximate operation of arithmetic coding and yet enables processing time in a circuit to be considerably reduced and which provides a highly accurate prediction method of a code amount. <P>SOLUTION: The coder is equipped with a code amount approximation circuit (200) for calculating a predictive code amount of a first coding unit (macro block) from multivalued data of the first coding unit generated from an input signal and performs the arithmetic coding of the input signal based on the predictive code amount. The code amount approximation circuit (200) includes: selectors (230, 231) which divide the multivalued data included in the first coding unit into a plurality of groups for each second coding unit; partial code amount approximation circuits (201-206) which is provided for each group and calculate a predictive code amount of the second coding unit from the multivalued data divided into a plurality of groups based on a probability state; and an adder (232) which adds all the predictive code amounts to output the predictive code amount of the first coding unit. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
