US 7,583,805 B2 · Late reverberation-based synthesis of auditory scenes

Abstract

A scheme for stereo and multi-channel synthesis of inter-channel correlation (ICC) (normalized cross-correlation) cues for parametric stereo and multi-channel coding. The scheme synthesizes ICC cues such that they approximate those of the original. For that purpose, diffuse audio channels are generated and mixed with the transmitted combined (e.g., sum) signal(s). The diffuse audio channels are preferably generated using relatively long filters with exponentially decaying Gaussian impulse responses. Such impulse responses generate diffuse sound similar to late reverberation. An alternative implementation for reduced computational complexity is proposed, where inter-channel level difference (ICLD), inter-channel time difference (ICTD), and ICC synthesis are all carried out in the domain of a single short-time Fourier transform (STFT), including the filtering for diffuse sound generation.

Claims49

Dependent claims

A method for synthesizing an auditory scene comprising:

processing at least one input channel to generate two or more processed input signals;
filtering the at least one input channel to generate two or more diffuse signals;
and combining the two or more diffuse signals with the two or more processed input signals to generate a plurality of output channels for the auditory scene, wherein processing the at least one input channel comprises:
converting the at least one input channel from a time domain into a frequency domain to generate a plurality of frequency-domain (FD) input signals;
delaying the FD input signals to generate a plurality of delayed FD signals;
and scaling the delayed FD signals to generate a plurality of scaled, delayed FD signals, and wherein:
the FD input signals are delayed based on inter-channel time difference (ICTD) data;
and the delayed FD signals are scaled based on inter-channel level difference (ICLD) and inter-channel correlation (ICC) data.

5 more elements

Apparatus for synthesizing an auditory scene, comprising:

a configuration of at least one time domain to frequency domain (TD-FD) converter and a plurality of filters, the configuration adapted to generate two or more processed FD input signals and two or more diffuse FD signals from at least one TD input channel;
two or more combiners adapted to combine the two or more diffuse FD signals with the two or more processed FD input signals to generate a plurality of synthesized FD signals;
and two or more frequency domain to time domain (FD-TD) converters adapted to convert the synthesized FD signals into a plurality of TD output channels for the auditory scene, wherein the configuration comprises:
a first TD-FD converter adapted to convert the at least one TD input channel into a plurality of FD input signals;
a plurality of delay nodes adapted to delay the FD input signals to generate a plurality of delayed FD signals;
and a plurality of multipliers adapted to scale the delayed FD signals to generate a plurality of scaled, delayed FD signals, wherein the apparatus is adapted to generate more than tow output channels from the at least one TD input channel, and wherein:
the delay nodes are adapted to delay the FD input signals based on inter-channel time difference (ICTD) data;
and the multipliers are adapted to scale the delayed FD signals based on inter-channel level difference (ICLD) and inter-channel correlation (ICC) data.

5 more elements

Apparatus for synthesizing an auditory scene, comprising:

a configuration of at least one time domain to frequency domain (TD-FD) converter and a plurality of filters, the configuration adapted to generate two or more processed FD input signals and two or more diffuse FD signals from at least one TD input channel;
two or more combiners adapted to combine the two or more diffuse FD signals with the two or more processed FD input signals to generate a plurality of synthesized FD signals;
and two or more frequency domain to time domain (FD-TD) converters adapted to convert the synthesized FD signals into a plurality of TD output channels for the auditory scene, wherein:
the configuration comprises:
a first TD-FD converter adapted to convert the at least one TD input channel into a plurality of FD input signals;
a plurality of delay nodes adapted to delay the FD input signals to generate a plurality of delayed FD signals;
and
a plurality of multipliers adapted to scale the delayed FD signals to generate a plurality of scaled, delayed FD signals;
the combiners are adapted to sum, for each output channel, one of the scaled, delayed FD signals and a corresponding one of the diffuse FD signals to generate one of the synthesized FD signals;
each filter is a TD late reverberation filter adapted to generate a different TD diffuse channel from the at least one TD input channel;
and
an other multiplier adapted to scale the FD diffuse signal to generate a scaled FD diffuse signal, wherein a corresponding combiner is adapted to combine the scaled FD diffuse signal with a corresponding one of the scaled, delayed FD signals to generate one of the synthesized FD signals;
and
wherein each other multiplier is adapted to scale the FD diffuse signal based on ICLD and ICC data.

11 more elements

Apparatus for synthesizing an auditory scene, comprising:

a configuration of at least one time domain to frequency domain (TD-FD) converter and a plurality of filters, the configuration adapted to generate two or more processed FD input signals and two or more diffuse FD signals from at least one TD input channel;
two or more combiners adapted to combine the two or more diffuse FD signals with the two or more processed FD input signals to generate a plurality of synthesized FD signals;
and two or more frequency domain to time domain (FD-TD) converters adapted to convert the synthesized FD signals into a plurality of TD output channels for the auditory scene, wherein:
the configuration comprises:
a first TD-FD converter adapted to convert the at least one TD input channel into a plurality of FD input signals;
a plurality of delay nodes adapted to delay the FD input signals to generate a plurality of delayed FD signals;
and
a plurality of multipliers adapted to scale the delayed FD signals to generate a plurality of scaled, delayed FD signals;
the combiners are adapted to sum, for each output channel, one of the scaled, delayed FD signals and a corresponding one of the diffuse FD signals to generate one of the synthesized FD signals;
each filter is an FD late reverberation filter adapted to generate a different FD diffuse signal from one of the FD input signals;
and
the configuration further comprises a further plurality of multipliers adapted to scale the FD diffuse signals to generate a plurality of scaled FD diffuse signals, wherein the combiners are adapted to combine the scaled FD diffuse signals with the scaled, delayed FD signals to generate the synthesized FD signals;
and wherein each other multiplier is adapted to scale the FD diffuse signal based on ICLD and ICC data.

10 more elements

Dependencies are inferred from the claim text.

Late reverberation-based synthesis of auditory scenes

Life of this patent

Late reverberation-based synthesis of auditory scenes

Life of this patent

Abstract

Claims49