Pitch cycle search range setting apparatus and pitch cycle search apparatus

摘要

An apparatus sets a pitch cycle search object in pitch cycle search processing for searching for a pitch cycle included in a linear predictive residual on a per subframe basis. A pitch cycle indicator of the apparatus sequentially outputs pitch cycle candidates within a predetermined pitch cycle search range at integral accuracy. A memory stores an integral component of a pitch cycle selected in pitch cycle search processing of a previous subframe. An adaptive sound source vector generator sets, as the pitch cycle search object in pitch cycle search processing in a processing subframe section, a group of candidates comprising a group of integral-accuracy pitch cycle candidates output from the pitch cycle indicator and a group of fractional-accuracy pitch cycle search candidates that cover a pitch cycle near an integral component of the pitch cycle read from the previous subframe integral pitch cycle memory using fractional accuracy.