Patent ID: 11887611
Assignee: FRAUNHOFER GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
Field: Computer technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 12:
13. A parametric frequency-domain audio decoding method comprising
decoding, using entropy decoding, from a data stream
a first spectrum of a first channel of a current frame of a multichannel audio signal, wherein the spectrum is subdivided into scale factor bands, and
for each scale factor band, a scale factor associated with the respective scale factor band,

checking, for a predetermined scale factor band, whether all spectral lines of the first spectrum within the predetermined scale factor band are zero,
responsive to all spectral lines within the predetermined scale factor band being zero, filling the first spectrum within the predetermined scale factor band with noise determined from spectral lines of
a previous frame of the multichannel audio signal, or
a second channel of the current frame of the multichannel audio signal, to obtain a second spectrum;

scaling the second spectrum within each scale factor band, including the predetermined scale factor band, using the scale factor of the respective scale factor band to obtain a third spectrum; and
subjecting the third spectrum to an inverse transform so as to acquire a time domain portion of the first channel of the multichannel audio signal.