SYSTEMS, METHODS, APPARATUS, AND COMPUTER-READABLE MEDIA FOR THREE-DIMENSIONAL AUDIO CODING USING BASIS FUNCTION COEFFICIENTS

• US 20140016786A1
• Filed: 03/15/2013
• Published: 01/16/2014
• Est. Priority Date: 07/15/2012
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Sen, Dipanjan
• Granted Patent: US 9,190,065 B2
• Time in Patent Office: Days
• US Class Current: 381/23
• CPC Class Codes: G10L 19/008 Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing
• CPC Class Codes: H04S 2400/01 Multi-channel, i.e. more than two input channels, sound reproduction with two speakers wherein the multi-channel information is substantially preserved
• CPC Class Codes: H04S 2400/03 Aspects of down-mixing multi-channel audio to configurations with lower numbers of playback channels, e.g. 7.1 -> 5.1 H04S2400/01 takes precedence
• CPC Class Codes: H04S 3/008 in which the audio signals are in digital form, i.e. employing more than two discrete digital channels data reduction aspects thereof based on psychoacoustics G10L19/02

Abstract

Systems, methods, and apparatus for a unified approach to encoding different types of audio inputs are described.

Claims

1. A method of audio signal processing, said method comprising:

encoding an audio signal and spatial information for the audio signal into a first set of basis function coefficients that describes a first sound field; and

combining the first set of basis function coefficients with a second set of basis function coefficients that describes a second sound field during a time interval to produce a combined set of basis function coefficients that describes a combined sound field during the time interval.

2. The method according to claim 1, wherein said audio signal is a frame of a corresponding stream of audio samples.

3. The method according to claim 1, wherein said audio signal is a frame of a pulse-code-modulation (PCM) stream.

4. The method according to claim 1, wherein said spatial information for the audio signal indicates a direction in space.

5. The method according to claim 1, wherein said spatial information for the audio signal indicates a location in space of a source of the audio signal.

6. The method according to claim 1, wherein said spatial information for the audio signal indicates a diffusivity of the audio signal.

7. The method according to claim 1, wherein said audio signal is a loudspeaker channel.

8. The method according to claim 1, wherein said method includes obtaining an audio object that includes said audio signal and said spatial information for said audio signal.

9. The method according to claim 1, wherein said method includes encoding a second audio signal and spatial information for the second audio signal into the second set of basis function coefficients.

10. The method according to claim 1, wherein each basis function coefficient of said first set of basis function coefficients corresponds to a unique one of a set of orthogonal basis functions.

11. The method according to claim 1, wherein each basis function coefficient of said first set of basis function coefficients corresponds to a unique one of a set of spherical harmonic basis functions.

12. The method according to claim 10, wherein said set of basis functions describes a space with higher resolution along a first spatial axis than along a second spatial axis that is orthogonal to the first spatial axis.

13. The method according to claim 1, wherein at least one of said first and second sets of basis function coefficients describes the corresponding sound field with higher resolution along a first spatial axis than along a second spatial axis that is orthogonal to the first spatial axis.

14. The method according to claim 1, wherein said first set of basis function coefficients describes the first sound field in at least two spatial dimensions, and wherein said second set of basis function coefficients describes the second sound field in at least two spatial dimensions.

15. The method according to claim 1, wherein at least one of said first and second sets of basis function coefficients describes the corresponding sound field in three spatial dimensions.

16. The method according to claim 1, wherein a total number of basis function coefficients in said first set of basis function coefficients is less than a total number of basis function coefficients in said second set of basis function coefficients.

17. The method according to claim 16, wherein the number of basis function coefficients in said combined set of basis function coefficients is at least equal to the number of basis function coefficients in said first set of basis function coefficients and is at least equal to the number of basis function coefficients in said second set of basis function coefficients.

18. The method according to claim 1, wherein said combining comprises, for each of at least a plurality of the basis function coefficients of said combined set of basis function coefficients, summing a corresponding basis function coefficient of said first set of basis function coefficients and a corresponding basis function coefficient of said second set of basis function coefficients to produce the basis function coefficient.

19. A non-transitory computer-readable data storage medium having tangible features that cause a machine reading the features to perform a method according to claim 1.

20. An apparatus for audio signal processing, said apparatus comprising:

means for encoding an audio signal and spatial information for the audio signal into a first set of basis function coefficients that describes a first sound field; and

means for combining the first set of basis function coefficients with a second set of basis function coefficients that describes a second sound field during a time interval to produce a combined set of basis function coefficients that describes a combined sound field during the time interval.

21. The apparatus according to claim 20, wherein said spatial information for the audio signal indicates a direction in space.

22. The apparatus according to claim 20, wherein said audio signal is a loudspeaker channel.

23. The apparatus according to claim 20, wherein said apparatus includes means for parsing an audio object that includes said audio signal and said spatial information for said audio signal.

24. The apparatus according to claim 20, wherein each basis function coefficient of said first set of basis function coefficients corresponds to a unique one of a set of orthogonal basis functions.

25. The apparatus according to claim 20, wherein each basis function coefficient of said first set of basis function coefficients corresponds to a unique one of a set of spherical harmonic basis functions.

26. The apparatus according to claim 20, wherein said first set of basis function coefficients describes the first sound field in at least two spatial dimensions, and wherein said second set of basis function coefficients describes the second sound field in at least two spatial dimensions.

27. The apparatus according to claim 20, wherein at least one of said first and second sets of basis function coefficients describes the corresponding sound field in three spatial dimensions.

28. The apparatus according to claim 20, wherein a total number of basis function coefficients in said first set of basis function coefficients is less than a total number of basis function coefficients in said second set of basis function coefficients.

29. An apparatus for audio signal processing, said apparatus comprising:

an encoder configured to encode an audio signal and spatial information for the audio signal into a first set of basis function coefficients that describes a first sound field; and

a combiner configured to combine the first set of basis function coefficients with a second set of basis function coefficients that describes a second sound field during a time interval to produce a combined set of basis function coefficients that describes a combined sound field during the time interval.

30. The apparatus according to claim 29, wherein said spatial information for the audio signal indicates a direction in space.

31. The apparatus according to claim 29, wherein said audio signal is a loudspeaker channel.

32. The apparatus according to claim 29, wherein said apparatus includes a parser configured to parse an audio object that includes said audio signal and said spatial information for said audio signal.

33. The apparatus according to claim 29, wherein each basis function coefficient of said first set of basis function coefficients corresponds to a unique one of a set of orthogonal basis functions.

34. The apparatus according to claim 29, wherein each basis function coefficient of said first set of basis function coefficients corresponds to a unique one of a set of spherical harmonic basis functions.

35. The apparatus according to claim 29, wherein said first set of basis function coefficients describes the first sound field in at least two spatial dimensions, and wherein said second set of basis function coefficients describes the second sound field in at least two spatial dimensions.

36. The apparatus according to claim 29, wherein at least one of said first and second sets of basis function coefficients describes the corresponding sound field in three spatial dimensions.

37. The apparatus according to claim 29, wherein a total number of basis function coefficients in said first set of basis function coefficients is less than a total number of basis function coefficients in said second set of basis function coefficients.