RATE CONTROLLER, RATE CONTROL METHOD, AND RATE CONTROL PROGRAM

摘要

Rate control is carried out in order to achieve optimal control of noise energy and bit rate. Disclosed is a rate controller (15) that carries out rate control based on NMR in an audio coding device (10) that divides frames generated from input signals into multiple scale factor bands and encodes each of the scale factor bands using scale factors. The controller has an NMR determining unit (1) that determines an NMR that does not exceed a target rate by means of a binary search, and a scale factor determining unit (2) that determines the maximum scale factor and rate corresponding to the NMR determined by the NMR determining unit (1) by means of a binary search. Each time that an NMR candidate value to be treated as a candidate for binary searching of an NMR is selected by the NMR determining unit (1), the scale factor determining unit (2) determines a scale factor for the NMR candidate value.