Apparatus for Encoding or Decoding an Encoded Multichannel Signal Using a Filling Signal Generated by a Broad Band Filter

A method of decoding an encoded multichannel signal, comprising:

• decoding an encoded base channel to acquire a decoded base channel;
• decorrelation filtering at least a portion of the decoded base channel to acquire a filling signal;
• and
• performing a multichannel processing using a spectral representation of the decoded base channel and a spectral representation of the filling signal,
• wherein the decorrelation filtering is a broad band filtering and the multichannel processing comprises applying a narrow band processing to the spectral representation of the decoded base channel and the spectral representation of the filling signal.

A non-transitory digital storage medium having a computer program stored thereon to perform, when said computer program is run by a computer, the method of decoding an encoded multichannel signal, comprising:

• decoding an encoded base channel to acquire a decoded base channel;
• decorrelation filtering at least a portion of the decoded base channel to acquire a filling signal;
• and
• performing a multichannel processing using a spectral representation of the decoded base channel and a spectral representation of the filling signal,
• wherein the decorrelation filtering is a broad band filtering and the multichannel processing comprises applying a narrow band processing to the spectral representation of the decoded base channel and the spectral representation of the filling signal.