Patent ID: 11972767
Assignee: DOLBY LABORATORIES LICENSING CORPORATION
Field: Computer technology (Electrical engineering)
Classification: CPC G  H | IPC G

Claim 15:
16. A method of providing an audio service, the method comprising:
receiving an input signal representing N audio channels, where N>1;
dividing the input signal into a time-domain sequence of frames;
transforming each frame of the time-domain sequence of frames into a respective frequency-domain representation having a plurality of frequency bands, each frequency band of the plurality of frequency bands including a respective plurality of frequency bins;
for each frame of the time-domain sequence of frames, calculating, based on the frequency-domain representation of the frame, a respective set of band-specific N×N covariance matrices, each of the band-specific N×N covariance matrices having covariances of the N audio channels corresponding to a respective one of the plurality of frequency bands;
for each frequency band of the plurality of frequency bands, calculating a respective smoothed band-specific covariance matrix by applying a low-pass filter to a sequence of band-specific N×N covariance matrices corresponding to the time-domain sequence of frames and further corresponding to the frequency band; and
generating an audio signal for the audio service using the respective frequency domain representations of the time-domain sequence of frames and further using corresponding sets of the respective smoothed band-specific covariance matrices.