公开(公告)号：EP2581905A4

公开(公告)日：2014-11-05

申请号：EP11792129

申请日：2011-06-06

Applicant: PANASONIC IP CORP AMERICA

Inventor： ISHIKAWA TOMOKAZU ,  NORIMATSU TAKESHI ,  ZHOU HUAN ,  CHONG KOK SENG ,  ZHONG HAISHAN

IPC: G10L21/038 ,  G10L21/04

CPC classification number: G10L19/02 ,  G10L21/038 ,  G10L21/04

Abstract: To provide a bandwidth extension method which allows reduction of computation amount in bandwidth extension and suppression of deterioration of quality in the bandwidth to be extended. In the bandwidth extension method: a low frequency bandwidth signal is transformed into a QMF domain to generate a first low frequency QMF spectrum (S11); pitch-shifted signals are generated by applying different shifting factors on the low frequency bandwidth signal (S12); a high frequency QMF spectrum is generated by time-stretching the pitch-shifted signals in the QMF domain (S13); the high frequency QMF spectrum is modified (S14); and the modified high frequency QMF spectrum is combined with the first low frequency QMF spectrum (S15).