Specifying spherical harmonic and/or higher order ambisonics coefficients in bitstreams

1. A method of generating a bitstream representative of a compressed version of audio content, the method comprising:

obtaining, by a processor of a device, a plurality of spherical harmonic coefficients representative of the audio content;

determining, by the processor and based on an analysis of the plurality of spherical harmonic coefficients, whether one or more of the plurality of spherical harmonic coefficients have information relevant in describing a sound field in three dimensions, wherein the plurality of spherical harmonic coefficients are representative of the sound field;

specifying an indication, in the bitstream stored to a memory of the device and by the processor, identifying that the determined one or more of the plurality of spherical harmonic coefficients having the information relevant in describing the sound field are included in the bitstream, and that remaining ones of the plurality of spherical harmonic coefficients having information not relevant in describing the sound field are not included in the bitstream;

specifying, in the bitstream and by the processor, the identified one or more of the plurality of spherical harmonic coefficients without specifying, in the bitstream, the remaining ones of the plurality of spherical harmonic coefficients having information not relevant in describing the sound field;

determining, by the processor, a target bitrate for the bitstream including the identified one or more of the plurality of spherical harmonic coefficients; and

bandwidth compressing, by the processor and according to the determined target bitrate, the identified one or more of the plurality of spherical harmonic coefficients in the bitstream.

2. The method of claim 1 , wherein the indication comprises a field having a plurality of bits with a different one of the plurality of bits identifying whether a corresponding one of the plurality of spherical harmonic coefficients is included in the bitstream.

3. The method of claim 1 , wherein the indication comprises a field having a plurality of bits equal to (1+n) 2 bits,

wherein n denotes an order of the plurality of spherical harmonic coefficients describing the sound field, and

wherein each of the plurality of bits identifies whether a corresponding one of the plurality of spherical harmonic coefficients is included in the bitstream.

4. The method of claim 1 ,

wherein the indication comprises a field in the bitstream having a plurality of bits with a different one of the plurality of bits identifying whether a corresponding one of the plurality of spherical harmonic coefficients is included in the bitstream, and

wherein specifying the identified plurality of spherical harmonic coefficients comprises specifying, in the bitstream, the identified one or more of the plurality of spherical harmonic coefficients directly after the field having the plurality of bits.

5. The method of claim 1 , further comprising determining that one or more of the plurality of spherical harmonic coefficients are above a threshold value,

wherein the indication comprises an indication identifying, in the bitstream, that the determined one or more of the plurality of spherical harmonic coefficients that are above the threshold value are specified in the bitstream.

6. A device configured to generate a bitstream representative of a compressed version of audio content, the device comprising:

one or more processors configured to:

obtain a plurality of spherical harmonic coefficients representative of the audio content;

determine, based on an analysis of the plurality of spherical harmonic coefficients, whether one or more of the plurality of spherical harmonic coefficients have information relevant in describing a sound field in three dimensions, wherein the plurality of spherical harmonic coefficients are representative of the sound field;

specify an indication, in the bitstream, identifying that the determined one or more of the plurality of spherical harmonic coefficients having the information relevant in describing the sound field are included in the bitstream, and that remaining ones of the plurality of spherical harmonic coefficients having information not relevant in describing the sound field are not included in the bitstream;

specify, in the bitstream, the identified one or more of the plurality of spherical harmonic coefficients without specifying, in the bitstream, the remaining ones of the plurality of spherical harmonic coefficients having information not relevant in describing the sound field;

determine a target bitrate for the bitstream including the identified one or more of the plurality of spherical harmonic coefficients; and

bandwidth compress, according to the determined target bitrate, the identified one or more of the plurality of spherical harmonic coefficients in the bitstream; and

a memory coupled to the one or more processors, and configured to store at least a portion of the bitstream.

7. The device of claim 6 , wherein the one or more processors are configured to specify a field having a plurality of bits with a different one of the plurality of bits identifying whether a corresponding one of the plurality of spherical harmonic coefficients is included in the bitstream.

8. The device of claim 6 , wherein the one or more processors are configured to specify a field having a plurality of bits equal to (1+n) 2 bits,

wherein n denotes an order of the plurality of spherical harmonic coefficients describing the sound field, and

wherein each of the plurality of bits identifies whether a corresponding one of the plurality of spherical harmonic coefficients is included in the bitstream.

9. The device of claim 6 ,

wherein the one or more processors are configured to specify a field in the bitstream having a plurality of bits with a different one of the plurality of bits identifying whether a corresponding one of the plurality of spherical harmonic coefficients is included in the bitstream, and

wherein the one or more processors are configured to specify, in the bitstream, the identified plurality of spherical harmonic coefficients directly after the field having the plurality of bits.

10. The device of claim 6 , wherein the one or more processors are further configured to determine that one or more of the plurality of spherical harmonic coefficients are above a threshold value, and

wherein the one or more processors are configured to specify the indication, in the bitstream, identifying that the determined one or more of the plurality of spherical harmonic coefficients that are above the threshold value are specified in the bitstream.

11. A device configured to generate a bitstream representative of a compressed version of audio content, the device comprising:

means for obtaining a plurality of spherical harmonic coefficients representative of the audio content;

means for determining, based on an analysis of the plurality of spherical harmonic coefficients, whether one or more of a plurality of spherical harmonic coefficients have information relevant in describing a sound field in three dimensions, wherein the plurality of spherical harmonic coefficients are representative of the sound field;

means for specifying, in the bitstream, an indication identifying that the determined one or more of the plurality of spherical harmonic coefficients having the information relevant in describing the sound field are included in the bitstream, and that remaining ones of the plurality of spherical harmonic coefficients having information not relevant in describing the sound field are not included in the bitstream;

means for specifying, in the bitstream, the identified one or more of the plurality of spherical harmonic coefficients without specifying, in the bitstream, the remaining ones of the plurality of spherical harmonic coefficients having information not relevant in describing the sound field

means for determining, by the processor, a target bitrate for the bitstream including the identified one or more of the plurality of spherical harmonic coefficients; and

means for bandwidth compressing, by the processor and according to the determined target bitrate, the identified one or more of the plurality of spherical harmonic coefficients in the bitstream.

12. The device of claim 11 , wherein the indication comprises a field having a plurality of bits with a different one of the plurality of bits identifying whether a corresponding one of the plurality of spherical harmonic coefficients is included in the bitstream.

13. The device of claim 11 , wherein the indication comprises a field having a plurality of bits equal to (1+n) 2 bits,

wherein n denotes an order of the plurality of spherical harmonic coefficients describing the sound field, and

wherein each of the plurality of bits identifies whether a corresponding one of the plurality of spherical harmonic coefficients is included in the bitstream.

14. The device of claim 11 ,

wherein the indication comprises a field in the bitstream having a plurality of bits with a different one of the plurality of bits identifying whether a corresponding one of the plurality of spherical harmonic coefficients is included in the bitstream, and

wherein the means for specifying the identified plurality of spherical harmonic coefficients comprises means for specifying, in the bitstream, the identified plurality of spherical harmonic coefficients directly after the field having the plurality of bits.

15. The device of claim 11 , further comprising means for determining that one or more of the plurality of spherical harmonic coefficients are above a threshold value,

wherein the means for specifying the indication identifying the determined one or more of the plurality of spherical harmonic coefficients that are included in the bitstream comprises means for specifying the indication identifying, in the bitstream, that the determined one or more of the plurality of spherical harmonic coefficients that are above the threshold value are specified in the bitstream.

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

obtain a plurality of spherical harmonic coefficients representative of audio content;

determine, based on an analysis of the plurality of spherical harmonic coefficients, whether one or more of the plurality of spherical harmonic coefficients have information relevant in describing a sound field in three dimensions, wherein the plurality of spherical harmonic coefficients are representative of the sound field;

specify, in a bitstream, an indication identifying that only the determined one or more of the plurality of spherical harmonic coefficients having the information relevant in describing the sound field are included in the bitstream, and that remaining ones of the plurality of spherical harmonic coefficients having information not relevant in describing the sound field are not included in the bitstream;

specify, in the bitstream, the identified one or more of the plurality of spherical harmonic coefficients without specifying, in the bitstream, the remaining ones of the plurality of spherical harmonic coefficients having information not relevant in describing the sound field

determine a target bitrate for the identified one or more of the plurality of spherical harmonic coefficients; and

bandwidth compress, according to the determined target bitrate, the identified one or more of the plurality of spherical harmonic coefficients.

17. A method of processing a bitstream representative of a compressed version of audio content, the method comprising:

bandwidth decompressing, by one or more processors, a compressed version of one or more of a plurality of spherical harmonic coefficients specified in the bitstream to obtain the one or more of the plurality of spherical harmonic coefficients, wherein the one or more of the plurality of spherical harmonic coefficients have information relevant in describing a sound field in three dimensions;

identifying, by the one or more processors and from the bitstream, that the one or more of the plurality of spherical harmonic coefficients are included in the bitstream, and that remaining ones of the plurality of spherical harmonic coefficients determined to have information not relevant in describing the sound field in three dimensions are not included in the bitstream, wherein the plurality of spherical harmonic coefficients are representative of the audio content, and the bitstream is formed to achieve a target bitrate;

parsing, by the one or more, the bitstream to determine the identified one or more of the plurality of spherical harmonic coefficients and not the remaining ones of the plurality of spherical harmonic coefficients;

render, by the one or more processors, the plurality of spherical harmonic coefficients to one or more speaker feeds; and

output, by the one or more processors, the one or more speaker feeds to one or more speakers.

18. The method of claim 17 , wherein identifying whether the one or more of the plurality of spherical harmonic coefficients are included in the bitstream comprises parsing the bitstream to identify a field having a plurality of bits with each one of the plurality of bits identifying whether a corresponding one of the plurality of spherical harmonic coefficients is included in the bitstream.

19. The method of claim 17 , wherein identifying whether the one or more of the plurality of spherical harmonic coefficients are included in the bitstream comprises parsing a field having a plurality of bits equal to (1+n) 2 bits,

wherein n denotes an order of the plurality of spherical harmonic coefficients describing the sound field, and

wherein each of the plurality of bits identify whether a corresponding one of the plurality of spherical harmonic coefficients is included in the bitstream.

20. The method of claim 17 ,

wherein identifying whether the one or more of the plurality of spherical harmonic coefficients are included in the bitstream comprises parsing a field in the bitstream having a plurality of bits with a different one of the plurality of bits identifying whether a corresponding one of the plurality of spherical harmonic coefficients is included in the bitstream, and

wherein parsing the bitstream to determine the identified one or more of the plurality of spherical harmonic coefficients comprises parsing the bitstream to determine the identified one or more of the plurality of spherical harmonic coefficients directly from the bitstream after the field having the plurality of bits.

21. The method of claim 17 , further comprising determining that one or more of the plurality of spherical harmonic coefficients are above a threshold value,

wherein identifying whether the one or more of the plurality of spherical harmonic coefficients are included in the bitstream comprises determining, from the bitstream, that the determined one or more of the plurality of spherical harmonic coefficients above the threshold value are specified in the bitstream.

22. A device configured to process a bitstream representative of a compressed version of audio content, the device comprising:

a memory configured to store at least a portion of the bitstream; and

one or more processors configured to:

bandwidth decompress a compressed version of one or more of a plurality of spherical harmonic coefficients specified in the bitstream to obtain one or more of a plurality of spherical harmonic coefficients, wherein the one of more of the plurality of spherical harmonic coefficients have information relevant in describing a sound field in three dimensions;

identify, from the bitstream, that the one or more of the plurality of spherical harmonic coefficients are included in the bitstream, and that remaining ones of the plurality of spherical harmonic coefficients determined to have information not relevant in describing the sound field in three dimensions are not included in the bitstream, wherein the plurality of spherical harmonic coefficients are representative of the audio content, and the bitstream is formed to achieve a target bitrate;

parse the bitstream to determine the identified one or more of the plurality of spherical harmonic coefficients and not the remaining ones of the plurality of spherical harmonic coefficients;

render the plurality of spherical harmonic coefficients to one or more speaker feeds; and

output the one or more speaker feeds to one or more speakers.

23. The device of claim 22 , wherein the one or more processors are configured to parse the bitstream to identify a field having a plurality of bits with each one of the plurality of bits identifying whether a corresponding one of the plurality of spherical harmonic coefficients is included in the bitstream.

24. The device of claim 22 , wherein the one or more processors are configured to parse a field from the bitstream having a plurality of bits equal to (1+n) 2 bits,

wherein n denotes an order of the plurality of spherical harmonic coefficients describing the sound field, and

wherein each of the plurality of bits identify whether a corresponding one of the plurality of spherical harmonic coefficients is included in the bitstream.

25. The device of claim 22 ,

wherein the one or more processors are configured to parse a field in the bitstream having a plurality of bits with a different one of the plurality of bits identifying whether a corresponding one of the plurality of spherical harmonic coefficients is included in the bitstream, and

wherein the one or more processors are configured to parse the bitstream to determine the identified one or more of the plurality of spherical harmonic coefficients directly from the bitstream after the field having the plurality of bits.

26. The device of claim 22 ,

wherein the one or more processors are further configured to determine that the one or more of the plurality of spherical harmonic coefficients are above a threshold value, and

wherein the one or more processors are configured to determine, from the bitstream, that the determined one or more of the plurality of spherical harmonic coefficients above the threshold value are specified in the bitstream.

27. A device configured to process a bitstream representative of a compressed version of audio content, the device comprising:

means for bandwidth decompressing a compressed version of one or more of a plurality of spherical harmonic coefficients specified in the bitstream to obtain one or more of a plurality of spherical harmonic coefficients, wherein the one of more of the plurality of spherical harmonic coefficients have information relevant in describing a sound field in three dimensions;

means for identifying, from the bitstream, that the one or more of the plurality of spherical harmonic coefficients are included in the bitstream, and that remaining ones of the plurality of spherical harmonic coefficients determined to have information not relevant in describing the sound field in three dimensions are not included in the bitstream, wherein the plurality of spherical harmonic coefficients are representative of the audio content, and the bitstream is formed to achieve a target bitrate;

means for parsing the bitstream to determine the identified one or more of the plurality of spherical harmonic coefficients and not the remaining ones of the plurality of spherical harmonic coefficients;

render the plurality of spherical harmonic coefficients to one or more speaker feeds; and

output the one or more speaker feeds to one or more speakers.

28. The device of claim 27 , wherein the means for identifying comprises means for parsing the bitstream to identify a field having a plurality of bits with each one of the plurality of bits identifying whether a corresponding one of the plurality of spherical harmonic coefficients is included in the bitstream.

29. The device of claim 27 , wherein the means for identifying comprises means for parsing a field from the bitstream having a plurality of bits equal to (1+n) 2 bits,

wherein n denotes an order of the plurality of spherical harmonic coefficients describing the sound field, and

wherein each of the plurality of bits identify whether a corresponding one of the plurality of spherical harmonic coefficients is included in the bitstream.

30. The device of claim 27 ,

wherein the means for identifying comprises means for parsing a field in the bitstream having a plurality of bits with a different one of the plurality of bits identifying whether a corresponding one of the plurality of spherical harmonic coefficients is included in the bitstream, and

wherein the means for parsing the bitstream to determine the identified one or more of the plurality of spherical harmonic coefficients comprises means for parsing the bitstream to determine the identified one or more of the plurality of spherical harmonic coefficients directly from the bitstream after the field having the plurality of bits.

31. The device of claim 27 , further comprising means for determining that the one or more of the plurality of spherical harmonic coefficients are above a threshold value,

wherein the means for identifying comprises means for determining, from the bitstream, that only the determined one or more of the plurality of spherical harmonic coefficients above the threshold value are specified in the bitstream.

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

bandwidth decompress a compressed version of one or more of a plurality of spherical harmonic coefficients specified in a bitstream to obtain one or more of a plurality of spherical harmonic coefficients, wherein the one of more of the plurality of spherical harmonic coefficients have information relevant in describing a sound field in three dimensions;

identify, from the bitstream, that the one or more of the plurality of spherical harmonic coefficients are included in the bitstream, and that remaining ones of the plurality of spherical harmonic coefficients determined to have information not relevant in describing the sound field in three dimensions are not included in the bitstream, wherein the plurality of spherical harmonic coefficients are representative of the audio content, and the bitstream is formed to achieve a target bitrate;

parse the bitstream to determine the identified one or more of the plurality of spherical harmonic coefficients and not the remaining ones of the plurality of spherical harmonic coefficients;

render the plurality of spherical harmonic coefficients to one or more speaker feeds; and

output the one or more speaker feeds to one or more speakers.