METHOD AND DEVICE OF EXTRACTING SOUND SOURCE ACOUSTIC IMAGE BODY IN 3D SPACE

摘要

The invention provides a method and device of extracting a sound source acoustic image body in 3D space. The method includes: determining a spatial position of a sound source acoustic image and determining a speaker beside the spatial position where the sound source acoustic image is located according to the determined spatial position (ρ, μ, η) of the sound source acoustic image; calculating a correlation of signals of all sound tracks of the selected speaker in the horizontal direction and the vertical direction, and obtaining and storing a parameter set {ICH, ICv, Min{ICH, ICv}} of a acoustic image body, wherein the Min{ICH, ICv} is a smaller value between ICH and ICv. The expression parameters of the acoustic image body obtained in the present invention are used for providing technical support for accurately restoring the size of the sound source acoustic image in a 3D audio live system, which solves the technical problem that the restored acoustic image in a 3D audio is excessively narrow at present.

主权项

1. A method of extracting a sound source acoustic image body in 3D space, the method comprises:
step 1, determining a spatial position of a sound source acoustic image, which is achieved by:
processing time-frequency conversion for a signal of each channel and processing the same sub-band division for each channel; and with the listener as a spherical coordinate system origin, for a speaker with the horizontal angle μi and elevation angle ηi, setting a vector pi(k,n) re presenting the time-frequency representation of the corresponding signal,pi(k,n)=gi(k,n)·[cosμi·cosηisinμi·cosηisinηi] wherein i refers to an index value of the speaker, k refers to a frequency band index, n refers to a time domain frame number index, gi(k,n) refers to a intensity information of a frequency domain point;
the horizontal angle μi and elevation angle ηi is calculated using the following formula,tanμ(k,n)=∑i=1Ngi(k,n)·cosμi·cosηi∑i=1Ngi(k,n)·sinμi·cosηitanη(k,n)=[∑i=1Ngi(k,n)·cosμi·cosηi]2+[∑i=1Ngi(k,n)·sinμi·cosηi]2∑i=1Ngi(k,n)·sinηi wherein, N refers to a total number of the speakers, i values for 1,2 . . . N, μ (k, n), η (k, n) i.e., the horizontal angle μ and elevation angle η of the sound source acoustic image in k-th frequency band of the n-th frame;
a distance ρ from the sound source acoustic image audio to the origin of the spherical coordinate system takes the average distance of distances from all the speakers to the listener; step 2, determining the speaker beside the spatial position where the sound source acoustic image is located according to the determined spatial position (ρ, μ, η) of the sound source acoustic image; step 3, calculating a correlation of signals of all sound tracks of the speakers selected at step 2 in the horizontal direction and the vertical direction, which is achieved by:
dividing the selected speakers into left part and right part according to the location of the acoustic image, using the vertical plane of the connecting line between the sound source acoustic image and the listener as a projection plane, calculating a sum of the components of the left and right signals which are perpendicular to the projection plane respectively, denoting the sums as PL and PR respectively, and calculating the correlation ICH of the left and right signals as follows,ICH=cov(PL,PR)cov(PL,PL)·cov(PR,PR) dividing the selected speakers into upper part and lower part according to the location of the acoustic image, using a plane where the sound source acoustic image and the listener are located as a projection plane, calculating a sum of the components of the upper and lower signals which are perpendicular to the projection plane respectively, denoting the sums as PU and PD respectively, and calculating the correlation ICv of the upper and lower signals as follows,ICV=cov(PU,PD)cov(PU,PU)·cov(PD,PD) step 4, obtaining and storing a parameter set {ICH, ICv, Min{ICH, ICv}} of the acoustic image body, wherein the Min{ICH, ICv} is a smaller value between ICH and ICv.