Method and apparatus for transforming coded information signals

摘要

A code transform apparatus performs fast data transform by enabling intercode data transform. The code transform apparatus includes a code-string decomposing unit for inputting a first code string obtained by coding a spectral signal which has been transformed with a first block length after a time-series information signal had been divided into a first band group. A signal-component decoding unit decodes the input first code string into a spectral signal. A spectral-signal transform unit transforms the decoded spectral signal into a spectral signal which is transformed with a second block length after being divided into a second band group. A signal-component coding unit and a code-string generating unit code the transformed spectral signal into a second code string. <IMAGE>