ENCODING RATE CONVERSION DEVICE, ENCODING RATE CONVERSION METHOD, AND INTEGRATED CIRCUIT

摘要

A plurality of macro-blocks constituting encoding data is inverse-quantized by using a first quantization matrix used for the encoding of a picture to acquire a plurality of pieces of coefficient data. The first quantization matrix is converted into a second quantization matrix by using a first conversion value for converting the value of the low-frequency coefficient corresponding to a frequency lower than a predetermined frequency and a second conversion value which is a value for converting the value of a high-frequency coefficient and larger than the first conversion value out of the coefficients indicated by the first quantization matrix (S408). If the second quantization matrix is a matrix for increasing the encoding rate of the encoding data, the converted scale value after the value of quantization scale corresponding to at least one macro-block is multiplied by ß1(=1) is calculated. At least a part of the plurality of pieces of coefficient data is quantized by using the second quantization matrix and the calculated converted scale value corresponding to the macro-block corresponding to the at least part of coefficient data.