US 12,273,696 B2
Method and device for applying dynamic range compression to a higher order ambisonics signal
Johannes Boehm, Göttingen (DE); and Florian Keiler, Hannover (DE)
Assigned to Dolby Laboratories Licensing Corporation, San Francisco, CA (US)
Filed by Dolby Laboratories Licensing Corporation, San Francisco, CA (US)
Filed on Nov. 9, 2023, as Appl. No. 18/505,494.
Application 17/144,325 is a division of application No. 16/857,093, filed on Apr. 23, 2020, granted, now 10,893,372, issued on Jan. 12, 2021.
Application 16/857,093 is a division of application No. 16/660,626, filed on Oct. 22, 2019, granted, now 10,638,244, issued on Apr. 28, 2020.
Application 16/660,626 is a division of application No. 16/457,135, filed on Jun. 28, 2019, granted, now 10,567,899, issued on Feb. 18, 2020.
Application 16/457,135 is a division of application No. 15/891,326, filed on Feb. 7, 2018, granted, now 10,362,424, issued on Jul. 23, 2019.
Application 15/891,326 is a division of application No. 15/127,775, granted, now 9,936,321, issued on Apr. 3, 2018, previously published as PCT/EP2015/056206, filed on Mar. 24, 2015.
Application 18/505,494 is a continuation of application No. 17/144,325, filed on Jan. 8, 2021, granted, now 11,838,738.
Claims priority of application No. 14305423 (EP), filed on Mar. 24, 2014; and application No. 14305559 (EP), filed on Apr. 15, 2014.
Prior Publication US 2024/0098436 A1, Mar. 21, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H04S 3/00 (2006.01); G10L 19/008 (2013.01); H04S 3/02 (2006.01)
CPC H04S 3/008 (2013.01) [G10L 19/008 (2013.01); H04S 3/02 (2013.01); H04S 2420/01 (2013.01); H04S 2420/11 (2013.01)] 3 Claims
OG exemplary drawing
 
1. A method for dynamic range compression (DRC), the method comprising:
receiving a reconstructed Higher Order Ambisonics (HOA) audio signal representation;
transforming the reconstructed HOA audio signal into a spatial domain based on:
WDSHT=DDSHTC, wherein DDSHT is an inverse Discrete Spherical Harmonics Transform (DSHT) matrix, wherein Cis a block of τ HOA samples, and
wherein Wis a block of spatial samples matching an input time granularity of a Quadrature Mirror Filter (QMF) bank;
applying a DRC gain value g(n, m) corresponding to a time frequency tile (n, m) based on:
w̌DRC(n, m)=diag(g(n, m)) ŵDSHT(n, m),
wherein ŵDSHT(n, m) is a vector of spatial channels for the time frequency tile (n, m); and
rendering to loudspeaker channels based on:
w(n, m)=D DDSHT−1 w̌DRC(n, m), wherein DDSHT−1 matrix is an inverse of the DDSHT matrix and D is a HOA rendering matrix,
wherein the DDSHT−1 and the DDSHT matrices are optimized for DRC purposes based on a row-vector e is calculated by

OG Complex Work Unit Math
and a matrix Ď2, where [1,0,0, . . . ,0] is a row vector of (N+1)2 all zero elements except for a first element with a value of one, wherein N is an HOA order, wherein

OG Complex Work Unit Math
wherein a compact singular value decomposition is performed D1=USVT and a new prototype matrix is calculated by: {tilde over (D)}2=UVT, wherein

OG Complex Work Unit Math
wherein a set of spherical positions custom characterDSHT=[Ω1,Ωl, . . . ,Ω)N+1)2] with Ωl=[θl, ϕl]T and related quadrature (cubature) gains custom character∈custom character(N+1)2×1 are selected and wherein a mode matrix ΨDSHT is related to the spherical positions.