ENCODER AND ENCODING METHOD, PROGRAM, AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide an encoder for setting a value of a Q matrix on the basis of a bit rate and a difficulty level of a picture.

SOLUTION: A flowchart explaining a Q matrix setting process 3 includes: a step S61 of discriminating whether or not a value of the bit rate is smaller than a threshold value A; a step S62 of discriminating whether or not a relation of mad_info > threshold value B holds when the bit rate value is smaller than the threshold value A; and a step S63 of revising the Q matrix to have first values for execution of rough quantization by excluding high frequency components because the difficulty level of a picture after a scene change is high and encoding is difficult in the case of mad_info > threshold value B; a step S64 of revising the Q matrix to have second values for execution of finer quantization than the rough quantization in comparison with the first values although the high frequency components are excluded more than the case with an ordinary processing because the difficulty level of a picture after a scene change is low and encoding is easy; and a step S65 of not revising the Q matrix values because there is a margin for the encoding when the bit rate is greater than the threshold value A.

COPYRIGHT: (C)2004,JPO