| 摘要 |
PROBLEM TO BE SOLVED: To remove signal of frequency band which will not be a coding object, by a low calculation amount. SOLUTION: It contains an image converter 11 for producing a frequency region signal in a frequency variable range, by performing image conversion for an input audio signal, a code amount indicator 12 for outputting a setting coded bit rate as a code amount, a frequency region signal compressed coding 13 for performing compressed coding process to the frequency region signal, based on the code amount and to produce a bit stream, and a band limiting section 10 to output the frequency region signal processed with band limitation to the frequency region signal compressed coding, indicating a part of a frequency variable range of the frequency region signal as a damped frequency variable range, multiplying a damping coefficient of less than 1 by the value of the frequency region signal in the damped frequency variable range and performing band limiting process for damping the frequency region signal in the damped frequency variable range. It removes a signal of frequency band which is not a coding subject by the low operation amount, damping the frequency region signal of the fixed frequency band. |
