US 12,266,372 B2
Parameter encoding and decoding
Alexandre Bouthéon, Erlangen (DE); Guillaume Fuchs, Erlangen (DE); Markus Multrus, Erlangen (DE); Fabian Küch, Erlangen (DE); Oliver Thiergart, Erlangen (DE); Stefan Bayer, Erlangen (DE); Sascha Disch, Erlangen (DE); and Jürgen Herre, Erlangen (DE)
Assigned to Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V., Munich (DE)
Filed by Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V., Munich (DE)
Filed on Dec. 14, 2021, as Appl. No. 17/550,953.
Application 17/550,953 is a continuation of application No. PCT/EP2020/066456, filed on Jun. 15, 2020.
Claims priority of application No. 19180385 (EP), filed on Jun. 14, 2019.
Prior Publication US 2022/0122621 A1, Apr. 21, 2022
Int. Cl. G10L 19/008 (2013.01); G10L 19/08 (2013.01); H04S 3/02 (2006.01)
CPC G10L 19/008 (2013.01) [G10L 19/08 (2013.01); H04S 3/02 (2013.01); H04S 2400/01 (2013.01); H04S 2400/03 (2013.01)] 13 Claims
OG exemplary drawing
 
1. An audio synthesizer for generating a synthesis signal from a downmix signal comprising a number of downmix channels, the synthesis signal comprising a number of synthesis channels, the downmix signal being a downmixed version of an original signal comprising a number of original channels, the audio synthesizer comprising:
a first path comprising:
a first mixing matrix block configured for synthesizing a first component of the synthesis signal according to a first mixing matrix calculated from:
a covariance matrix of the synthesis signal; and
a covariance matrix of the downmix signal,
a second path for synthesizing a second component of the synthesis signal, wherein the second component is a residual component, the second path comprising:
a prototype signal block configured for upmixing the downmix signal from the number of downmix channels to the number of synthesis channels;
a decorrelator configured for decorrelating the upmixed prototype signal;
a second mixing matrix block configured for synthesizing the second component of the synthesis signal according to a second mixing matrix from the decorrelated version of the downmix signal, the second mixing matrix being a residual mixing matrix,
wherein the audio synthesizer is configured to calculate the second mixing matrix from:
the residual covariance matrix provided by the first mixing matrix block; and
an estimate of the covariance matrix of the decorrelated prototype signals acquired from the covariance matrix of the downmix signal,
wherein the audio synthesizer further comprises an adder block for summing the first component of the synthesis signal with the second component of the synthesis signal.