ENCODING METHOD ENCODING DEVICE PERIODIC FEATURE AMOUNT DETERMINATION METHOD PERIODIC FEATURE AMOUNT DETERMINATION DEVICE PROGRAM AND RECORDING MEDIUM

摘要

The present invention provides an encoding technique im- proving the quality of acoustic signals b y low-bit encoding with low com plexity. This encoding technique includes: interval determination processing that determines an interval (T) o f a sample corresponding t o the periodicity o f an acoustic signal o r an interval o f a sample corresponding t o the in tegral multiple o f the basic frequency o f the acoustic signal for each o f frames from among aggregation (S) o f candidates for the interval (T); and auxiliary information generation processing that encodes the interval d e termined b y the interval determination processing t o obtain auxiliary inform ation. The interval determination processing determines the interval (T) by defining, as the aggregation (S), aggregation configured by (Y) number of candidates (where YZ) b y (Z2) number of candidates (where Z2Z) selected independent of candidates targeted for the interval determination step in past frames only for a predetermined number of frames, and candidates targeted for the interval determination processing in the past frames only for the pre determined number o f frames, among (Z) number of candidates for the interval (T) representable with the auxiliary information.