To greatly reduce a quantity of bit distribution calculation processing by calculating the processing for bit distribution that shares nearly a half the compression processing of the image audio compressor, based on a scale factor.
An MPEG audio processing section 107 comprises a sub-band analysis section 101 that divides data sampled at a prescribed interval into 32 sub-bands, a scaling section 102 that normalizes a maximum level of an output of the sub-band analysis section 101 to obtain a scale factor, a scale factor selection information calculation section 103 that uses a scale factor in common when changes in scale factors are less, a bit distribution calculation section 104 for each sub-band, a quantization section 105 that uses the calculated bit distribution and the calculated scale factor to quantize the data processed by the sub-band analysis section 101, and a bit stream generating section 106 that generates an audio stream, based on a header, the bit distribution, an SCFSI (scale factor election information), the scale factor of each sub-band, and the quantized data and calculates the bit distribution, based on the scale factor.
SHIOKAWA JUNJI
YAZAWA FUMISHIGE
