DETERMINING RENDERERS FOR SPHERICAL HARMONIC COEFFICIENTS

• US 20140219456A1
• Filed: 02/06/2014
• Published: 08/07/2014
• Est. Priority Date: 02/07/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Morrell, Martin James, Peters, Nils Gnther, Sen, Dipanjan
• Granted Patent: US 9,736,609 B2
• Time in Patent Office: Days
• US Class Current: 381/17
• CPC Class Codes: H04S 2400/11 Positioning of individual sound objects, e.g. moving airplane, within a sound field H04S2420/13 takes precedence
• CPC Class Codes: H04S 2420/11 Application of ambisonics in stereophonic audio systems
• CPC Class Codes: H04S 5/00 Pseudo-stereo systems, e.g. in which additional channel signals are derived from monophonic signals by means of phase shifting, time delay or reverberation
• CPC Class Codes: H04S 7/30 Control circuits for electronic adaptation of the sound field
• CPC Class Codes: H04S 7/301 Automatic calibration of stereophonic sound system, e.g. with test microphone

Abstract

In general, techniques are described for determining renderers used for rendering spherical harmonic coefficients to generate one or more loudspeaker signals. A device comprising one or more processors may perform the techniques. The one or more processors may be configured to determine a local speaker geometry of one or more speakers used for playback of spherical harmonic coefficients representative of a sound field, and configure the device to operate based on the local speaker geometry.

Claims

1. A method comprising:

determining a local speaker geometry of one or more speakers used for playback of spherical harmonic coefficients representative of a sound field; and

determining a two-dimensional or three-dimensional renderer based on the local speaker geometry.

2. The method of claim 1, further comprising rendering the spherical harmonic coefficients using the determined two-dimensional or three-dimensional renderer to generate multi-channel audio data.

3. The method of claim 1, wherein determining the two-dimensional or three-dimensional renderer based on the local speaker geometry comprises, when the local speaker geometry conforms to a stereo speaker geometry, determining a two-dimensional stereo renderer.

4. The method of claim 1, wherein determining the two-dimensional or three-dimensional renderer based on the local speaker geometry comprises, when the local speaker geometry conforms to horizontal multi-channel speaker geometry having more than two speakers, determining a horizontal two-dimensional multi-channel renderer.

5. The method of claim 4, wherein determining the horizontal two-dimensional multi-channel renderer comprises determining an irregular horizontal two-dimensional multi-channel renderer when the determined local speaker geometry indicates an irregular speaker geometry.

6. The method of claim 4, wherein determining the horizontal two-dimensional multi-channel renderer comprises determining a regular horizontal two-dimensional multi-channel renderer when the determined local speaker geometry indicates a regular speaker geometry.

7. The method of claim 1, wherein determining the two-dimensional or three-dimensional renderer based on the local speaker geometry comprises, when the local speaker geometry conforms a three-dimensional multi-channel speaker geometry having more than two speakers on more than one horizontal plane, determining a three-dimensional multi-channel renderer.

8. The method of claim 7, wherein determining the three-dimensional multi-channel renderer comprises determining an irregular three-dimensional multi-channel renderer when the determined local speaker geometry indicates an irregular speaker geometry.

9. The method of claim 7, wherein determining the three-dimensional multi-channel renderer comprises determining a near regular three-dimensional multi-channel renderer when the determined local speaker geometry indicates a near regular speaker geometry.

10. The method of claim 7, wherein determining the three-dimensional multi-channel renderer comprises determining a regular three-dimensional multi-channel renderer when the determined local speaker geometry indicates a regular speaker geometry.

11. The method of claim 1, wherein determining the renderer comprises:

determining an allowed order of spherical basis functions to which the spherical harmonic coefficients are associated, the allowed order identifying those of the spherical harmonic coefficients that are required to be rendered given the determined local speaker geometry; and

determining the renderer based on the determined allowed order.

12. The method of claim 1, wherein determining the two-dimensional or three-dimensional renderer comprises:

determining an allowed order of spherical basis functions to which the spherical harmonic coefficients are associated, the allowed order identifying those of the spherical harmonic coefficients that are required to be rendered given the determined local speaker geometry; and

determining the two-dimensional or three-dimensional renderer such that the two-dimensional or three-dimensional renderer only renders those of the spherical harmonic coefficients associated with spherical basis functions having an order less than or equal to the determined allowed order.

13. The method of claim 1, wherein determining the local speaker geometry of the one or more speakers comprises receiving input from a listener specifying local speaker geometry information describing the local speaker geometry.

14. The method of claim 1, wherein determining the two-dimensional or three-dimensional renderer based on the local speaker geometry comprises, when the local speaker geometry conforms to a mono speaker geometry, determining a mono renderer.

15. A device comprising:

one or more processors configured to determine a local speaker geometry of one or more speakers used for playback of spherical harmonic coefficients representative of a sound field and configure the device to operate based on the determined local speaker geometry.

16. The device of claim 15, wherein the one or more processors are further configured to, when configuring the device to operate based on the determined local speaker geometry, determine a two-dimensional or three-dimensional renderer based on the local speaker geometry, and configure the device to operate in accordance with the determined two-dimensional or three-dimensional renderer.

17. The device of claim 16, wherein the one or more processors are further configured to render the spherical harmonic coefficients using the determined two-dimensional or three-dimensional renderer to generate multi-channel audio data.

18. The device of claim 16, wherein the one or more processors are further configured to, when determining the two-dimensional or three-dimensional renderer based on the local speaker geometry, determine, when the local speaker geometry conforms to a stereo speaker geometry, a two-dimensional stereo renderer.

19. The device of claim 16, wherein the one or more processors are further configured to, when determining the two-dimensional or three-dimensional renderer based on the local speaker geometry, determine, when the local speaker geometry conforms to horizontal multi-channel speaker geometry having more than two speakers, a horizontal two-dimensional multi-channel renderer.

20. The device of claim 19, wherein the one or more processors are further configured to, when determining the horizontal two-dimensional multi-channel renderer, determine an irregular horizontal two-dimensional multi-channel renderer when the determined local speaker geometry indicates an irregular speaker geometry.

21. The device of claim 19, wherein the one or more processors are further configured to, when determining the horizontal two-dimensional multi-channel renderer, determine a regular horizontal two-dimensional multi-channel renderer when the determined local speaker geometry indicates a regular speaker geometry.

22. The device of claim 16, wherein the one or more processors are further configured to, when determining the two-dimensional or three-dimensional renderer based on the local speaker geometry, determine, when the local speaker geometry conforms a three-dimensional multi-channel speaker geometry having more than two speakers on more than one horizontal plane, a three-dimensional multi-channel renderer.

23. The device of claim 22, wherein the one or more processors are further configured to, when determining the three-dimensional multi-channel renderer, determine an irregular three-dimensional multi-channel renderer when the determined local speaker geometry indicates an irregular speaker geometry.

24. The device of claim 22, wherein the one or more processors are further configured to, when determining the three-dimensional multi-channel renderer, determine a near regular three-dimensional multi-channel renderer when the determined local speaker geometry indicates a near regular speaker geometry.

25. The device of claim 22, wherein the one or more processors are further configured to, when determining the three-dimensional multi-channel renderer, determine a regular three-dimensional multi-channel renderer when the determined local speaker geometry indicates a regular speaker geometry.

26. The device of claim 16, wherein the one or more processors are further configured to, when determining the renderer, determine an allowed order of spherical basis functions to which the spherical harmonic coefficients are associated, the allowed order identifying those of the spherical harmonic coefficients that are required to be rendered given the determined local speaker geometry, and determine the renderer based on the determined allowed order.

27. The device of claim 16, wherein the one or more processors are further configured to, when determining the two-dimensional or three-dimensional renderer, determine an allowed order of spherical basis functions to which the spherical harmonic coefficients are associated, the allowed order identifying those of the spherical harmonic coefficients that are required to be rendered given the determined local speaker geometry, and determine the two-dimensional or three-dimensional renderer such that the two-dimensional or three-dimensional renderer only renders those of the spherical harmonic coefficients associated with spherical basis functions having an order less than or equal to the determined allowed order.

28. The device of claim 16, wherein the one or more processors are further configured to, when determining the local speaker geometry of the one or more speakers, receive input from a listener specifying local speaker geometry information describing the local speaker geometry.

29. The device of claim 16, wherein the one or more processors are further configured to, when determining the two-dimensional or three-dimensional renderer based on the local speaker geometry, determine, when the local speaker geometry conforms to a mono speaker geometry, a mono renderer.

30. A non-transitory computer-readable storage medium having stored thereon instructions that, when executed, cause one or more processors to:

determine a local speaker geometry of one or more speakers used for playback of spherical harmonic coefficients representative of a sound field; and

determine a two-dimensional or three-dimensional renderer based on the local speaker geometry.