Adaptive panner of audio objects

1. A computer-implemented method, comprising:

receiving an audio object comprising audio content and object metadata, the object metadata of the audio object indicating an object spatial position of the audio object to be rendered by a plurality of audio speakers in a playback environment, each audio speaker in the plurality of audio speakers being located in a respective source spatial position in a plurality of source spatial positions in the playback environment;

determining, based on the object spatial position of the audio object and the plurality of source spatial positions of the plurality of audio speakers, a plurality of initial gain values for the plurality of audio speakers, each audio speaker in the plurality of audio speakers being assigned with a respective initial gain value in the plurality of initial gain values;

determining, based on the object spatial position of the audio object and a set of source spatial positions at which the set of audio speakers are respectively located in the playback environment, a set of optimized gain values for the set of audio speakers wherein the set of optimized gain values are non-negative;

causing the audio object at the object spatial position to be rendered with the set of optimized gain values for the set of audio speakers, each audio speaker in the set of audio speakers being assigned with a respective optimized gain value in the set of optimized gain values; and

using one or more initial gain values below a gain value threshold among the plurality of initial gain values to deactivate one or more corresponding audio sources, in the plurality of audio speakers in the playback environment, from taking part in rendering the audio object located at the object spatial position.

2. The method of claim 1 , wherein the plurality of initial gain values include one or more negative initial gain values.

3. The method of claim 1 , wherein the plurality of initial gain values include one or more zero and negative initial gain values.

4. The method of claim 1 , wherein the plurality of initial gain values is generated by a first gain calculation method that generates nonnegative gain values and negative gain values; and wherein the set of optimized gain values is generated by a second gain calculation method that maintains nonnegativity of nonnegative optimized gain values and turns negative gain values non-negative.

5. The method of claim 4 , wherein the first gain calculation method represents one of an inverse-matrix gain calculation method, or a gain calculation method that does not preclude negative gain values.

6. The method of claim 4 , wherein the second gain calculation method represents one of a multiplicative-update gain method, an interior point method, a quadratic-programming gain method, a gradient descent gain method, or a gain method that maintains nonnegativity of nonnegative optimized gain values and turns negative gain values non-negative.

7. The method of claim 1 , wherein the object spatial position represents a spatial position in a spatial trajectory of the audio object, and/or

wherein the object spatial position is related to audio content in one of one or more audio frames, or one or more subdivision of an audio frame.

8. The method of claim 1 , wherein the plurality of initial gain values for the plurality of audio speakers are at least in part derived through interpolating precomputed optimized gain values for the plurality of audio speakers in the playback environment.

9. The method of claim 8 , wherein the precomputed optimized gain values are a part of a plurality of sets of precomputed optimized gain values for a plurality of precomputed object spatial positions in the playback environment, and optionally

wherein the plurality of precomputed object spatial positions in the playback environment is determined based on a specific sparseness setting.

10. The method of claim 8 , wherein the precomputed optimized gain values are precomputed and stored in a lookup table in offline processing.

11. The method of claim 1 , further comprising:

while in offline processing:

selecting, based on one or more selection criteria, a specific sparseness setting from among a plurality of selectable sparseness settings, the specific sparseness setting determining a plurality of precomputed spatial positions in the playback environment;

generating a plurality of sets of precomputed optimized gain values for the plurality of precomputed spatial positions, each set of precomputed optimized gain values in the plurality of sets of precomputed optimized gain values corresponding to a respective precomputed spatial position in the plurality of precomputed spatial positions;

while in online processing:

deriving the plurality of initial gain values for the plurality of audio speakers at least in part from interpolated gain values from the plurality of sets of precomputed optimized gain values.

12. The method of claim 11 , further comprising:

while in the online processing:

performing optimization of the interpolated gain values to determine the plurality of initial gain values for the plurality of audio speakers.

13. The method of claim 11 , wherein the plurality of initial gain values for the plurality of audio speakers are directly set to the interpolated gain values in the online processing.

14. The method of claim 1 , further comprising using the plurality of initial gain values to select a set of audio speakers from among the plurality of audio speakers.

15. An apparatus, comprising:

a processor,

wherein the processor is configured to receive an audio object comprising audio content and object metadata, the object metadata of the audio object indicating an object spatial position of the audio object to be rendered by a plurality of audio speakers in a playback environment, each audio speaker in the plurality of audio speakers being located in a respective source spatial position in a plurality of source spatial positions in the playback environment;

wherein the processor is configured to determine, based on the object spatial position of the audio object and the plurality of source spatial positions of the plurality of audio speakers, a plurality of initial gain values for the plurality of audio speakers, each audio speaker in the plurality of audio speakers being assigned with a respective initial gain value in the plurality of initial gain values;

wherein the processor is configured to determine, based on the object spatial position of the audio object and a set of source spatial positions at which the set of audio speakers are respectively located in the playback environment, a set of optimized gain values for the set of audio speakers, wherein the set of optimized gain values are non-negative;

wherein the processor is configured to cause the audio object at the object spatial position to be rendered with the set of optimized gain values for the set of audio speakers, each audio speaker in the set of audio speakers being assigned with a respective optimized gain value in the set of optimized gain values; and

wherein the processor is configured to use one or more initial gain values below a gain value threshold among the plurality of initial gain values to deactivate one or more corresponding audio sources, in the plurality of audio speakers in the playback environment, from taking part in rendering the audio object located at the object spatial position.

16. The apparatus of claim 15 , wherein the plurality of initial gain values include one or more negative initial gain values.

17. The apparatus of claim 15 , wherein the plurality of initial gain values include one or more zero and negative initial gain values.

18. The apparatus of claim 15 , wherein the processor is configured to generate the plurality of initial gain values using a first gain calculation method that generates nonnegative gain values and negative gain values; and wherein the processor is configured to generate the set of optimized gain values using a second gain calculation method that maintains nonnegativity of nonnegative optimized gain values and turns negative gain values non-negative.

19. The apparatus of claim 18 , wherein the first gain calculation method represents one of an inverse-matrix gain calculation method, or a gain calculation method that does not preclude negative gain values.

20. The apparatus of claim 18 , wherein the second gain calculation method represents one of a multiplicative-update gain method, an interior point method, a quadratic-programming gain method, a gradient descent gain method, or a gain method that maintains nonnegativity of nonnegative optimized gain values and turns negative gain values non-negative.

21. The apparatus of claim 15 , wherein the object spatial position represents a spatial position in a spatial trajectory of the audio object, and/or

wherein the object spatial position is related to audio content in one of one or more audio frames, or one or more subdivision of an audio frame.

22. The apparatus of claim 15 , wherein the plurality of initial gain values for the plurality of audio speakers are at least in part derived through interpolating precomputed optimized gain values for the plurality of audio speakers in the playback environment.

23. The apparatus of claim 22 , wherein the precomputed optimized gain values are a part of a plurality of sets of precomputed optimized gain values for a plurality of precomputed object spatial positions in the playback environment, and optionally

wherein the plurality of precomputed object spatial positions in the playback environment is determined based on a specific sparseness setting.

24. The apparatus of claim 22 , wherein the precomputed optimized gain values are precomputed and stored in a lookup table in offline processing.

25. The apparatus of claim 15 , wherein:

while in offline processing:

the processor is configured to select, based on one or more selection criteria, a specific sparseness setting from among a plurality of selectable sparseness settings, the specific sparseness setting determining a plurality of precomputed spatial positions in the playback environment;

the processor is configured to generate a plurality of sets of precomputed optimized gain values for the plurality of precomputed spatial positions, each set of precomputed optimized gain values in the plurality of sets of precomputed optimized gain values corresponding to a respective precomputed spatial position in the plurality of precomputed spatial positions;

while in online processing:

the processor is configured to derive the plurality of initial gain values for the plurality of audio speakers at least in part from interpolated gain values from the plurality of sets of precomputed optimized gain values.

26. The apparatus of claim 25 , wherein:

while in the online processing:

the processor is configured to perform optimization of the interpolated gain values to determine the plurality of initial gain values for the plurality of audio speakers.

27. The apparatus of claim 25 , wherein the plurality of initial gain values for the plurality of audio speakers are directly set to the interpolated gain values in the online processing.

28. The apparatus of claim 15 , wherein the processor is configured to use the plurality of initial gain values to select a set of audio speakers from among the plurality of audio speakers.