Systems, methods, apparatus, and computer-readable media for dynamic bit allocation

• US 9,236,063 B2
• Filed: 07/28/2011
• Issued: 01/12/2016
• Est. Priority Date: 07/30/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Duni, Ethan Robert, Krishnan, Venkatesh, Rajendran, Vivek
• Primary Examiner(s): Yen, Eric
• Application Number:
  US13/193,529
• Publication Number:
  US 20120029925A1
• Time in Patent Office: 1,629 Days
• Field of Search: 704500-502, 704/E19.022
• US Class Current: 1/1
• CPC Class Codes: G10L 19/038 Vector quantisation, e.g. TwinVQ audio
• CPC Class Codes: G10L 19/093 using sinusoidal excitation models
• CPC Class Codes: G10L 25/90 Pitch determination of speech signals

Abstract

A method of bit allocation is described. The method includes, for each among a plurality of vectors, calculating a corresponding one of a plurality of gain factors. The method also includes, for each among the plurality of vectors, calculating a corresponding bit allocation that is based on the gain factor. The method further includes, for at least one among the plurality of vectors, determining that the corresponding bit allocation is not greater than a minimum allocation value. The method additionally includes, in response to the determining, for each of the at least one vector, changing the corresponding bit allocation.

Claims

1. A method of dynamic bit allocation for encoding audio signals, said method comprising:

for each among a plurality of vectors, calculating a corresponding one of a plurality of gain factors;

for each among the plurality of vectors, calculating, by an audio encoding electronic apparatus, a corresponding bit allocation that is based on a corresponding gain factor;

for at least one vector among the plurality of vectors, determining that a corresponding bit allocation is not greater than a corresponding minimum allocation value, wherein each corresponding minimum allocation value is calculated based on a corresponding vector length and based on a value, wherein the value is the same for each of said at least one vector;

in response to said determining, for each of said at least one vector, changing, by the audio encoding electronic apparatus, a corresponding bit allocation; and

encoding each vector of the plurality of vectors into a corresponding allocated number of bits.

2. The method of dynamic bit allocation according to claim 1, wherein a first minimum allocation value corresponding to a first vector among the plurality of vectors is different from a second minimum allocation value corresponding to a second vector among the plurality of vectors.

3. The method of dynamic bit allocation according to claim 1, wherein each corresponding minimum allocation value is calculated as a minimum of a corresponding vector length and the value.

4. The method of dynamic bit allocation according to claim 1, wherein each corresponding minimum allocation value is calculated according to a monotonically nondecreasing function of a corresponding vector length.

5. The method of dynamic bit allocation according to claim 1, wherein said method comprises, for each among the plurality of vectors, calculating a value of a corresponding vector'"'"'s energy distribution, and

wherein, for each among the plurality of vectors, a corresponding bit allocation is based on a corresponding value of a corresponding vector'"'"'s energy distribution.

6. The method of dynamic bit allocation according to claim 1, wherein said method comprises, for at least one among the plurality of vectors:

determining that a corresponding bit allocation does not correspond to a valid codebook index length, and

reducing a corresponding bit allocation in response to said determining.

7. The method of dynamic bit allocation according to claim 1, wherein, for at least one among the plurality of vectors, a corresponding bit allocation is an index length of a codebook of patterns that each have n unit pulses, and said method comprises calculating a number of bits between a corresponding bit allocation and an index length of a codebook of patterns that each have (n+1) unit pulses.

8. The method of dynamic bit allocation according to claim 1, wherein said method comprises calculating, from each among the plurality of vectors, a corresponding gain factor and a corresponding shape vector.

9. The method of dynamic bit allocation according to claim 1, wherein said method comprises determining a length of each of the plurality of vectors,

wherein said determining a length of each of the plurality of vectors is based on locations of a second plurality of vectors, and

wherein a frame of an audio signal includes the plurality of vectors and the second plurality of vectors.

10. The method of dynamic bit allocation according to claim 1, wherein the plurality of gain factors are calculated by dequantizing a corresponding quantized gain vector.

11. An apparatus for dynamic bit allocation for encoding audio signals, said apparatus comprising:

means for calculating, for each among a plurality of vectors, a corresponding one of a plurality of gain factors;

means for calculating, for each among the plurality of vectors, a corresponding bit allocation that is based on a corresponding gain factor;

means for determining, for at least one vector among the plurality of vectors, that a corresponding bit allocation is not greater than a corresponding minimum allocation value, wherein each corresponding minimum allocation value is calculated based on a corresponding vector length and based on a value, wherein the value is the same for each of said at least one vector;

means for changing a corresponding bit allocation, in response to said determining, for each of said at least one vector; and

means for encoding each vector of the plurality of vectors into a corresponding allocated number of bits.

12. The apparatus for dynamic bit allocation according to claim 11, wherein a first minimum allocation value corresponding to a first vector among the plurality of vectors is different from a second minimum allocation value corresponding to a second vector among the plurality of vectors.

13. The apparatus for dynamic bit allocation according to claim 11, wherein each corresponding minimum allocation value is calculated as a minimum of a corresponding vector length and the value.

14. The apparatus for dynamic bit allocation according to claim 11, wherein each corresponding minimum allocation value is calculated according to a monotonically nondecreasing function of a corresponding vector length.

15. The apparatus for dynamic bit allocation according to claim 11, wherein said apparatus includes means for calculating, for each among the plurality of vectors, a value of a corresponding vector'"'"'s energy distribution, and

wherein, for each among the plurality of vectors, a corresponding bit allocation is based on a corresponding value of a corresponding vector'"'"'s energy distribution.

16. The apparatus for dynamic bit allocation according to claim 11, wherein said apparatus comprises means for determining, for at least one among the plurality of vectors, that a corresponding bit allocation does not correspond to a valid codebook index length, and for reducing a corresponding bit allocation in response to said determining.

17. The apparatus for dynamic bit allocation according to claim 11, wherein, for at least one among the plurality of vectors, a corresponding bit allocation is an index length of a codebook of patterns that each have n unit pulses, and said apparatus comprises means for calculating a number of bits between a corresponding bit allocation and an index length of a codebook of patterns that each have (n+1) unit pulses.

18. The apparatus for dynamic bit allocation according to claim 11, wherein said apparatus comprises means for calculating, from each among the plurality of vectors, a corresponding gain factor and a corresponding shape vector.

19. The apparatus for dynamic bit allocation according to claim 11, wherein said apparatus comprises means for determining a length of each of the plurality of vectors,

wherein said determining a length of each of the plurality of vectors is based on locations of a second plurality of vectors, and

wherein a frame of an audio signal includes the plurality of vectors and the second plurality of vectors.

20. The apparatus for dynamic bit allocation according to claim 11, wherein the plurality of gain factors are calculated by means for dequantizing a corresponding quantized gain vector.

21. An apparatus for dynamic bit allocation for encoding audio signals, said apparatus comprising:

a processor;

a gain factor calculator configured to calculate, for each among a plurality of vectors, a corresponding one of a plurality of gain factors;

a bit allocation calculator configured to calculate, for each among the plurality of vectors, a corresponding bit allocation that is based on a corresponding gain factor;

a comparator configured to determine, for at least one vector among the plurality of vectors, that a corresponding bit allocation is not greater than a corresponding minimum allocation value, wherein each corresponding minimum allocation value is calculated based on a corresponding vector length and based on a value, wherein the value is the same for each of said at least one vector;

an allocation adjustment module configured to change a corresponding bit allocation, in response to said determining, for each of said at least one vector; and

an encoder configured to encode each vector of the plurality of vectors into a corresponding allocated number of bits.

22. The apparatus for dynamic bit allocation according to claim 21, wherein a first minimum allocation value corresponding to a first vector among the plurality of vectors is different from a second minimum allocation value corresponding to a second vector among the plurality of vectors.

23. The apparatus for dynamic bit allocation according to claim 21, wherein each corresponding minimum allocation value is calculated as a minimum of a corresponding vector length and the value.

24. The apparatus for dynamic bit allocation according to claim 21, wherein the corresponding minimum allocation value is calculated according to a monotonically nondecreasing function of a corresponding vector length.

25. The apparatus for dynamic bit allocation according to claim 21, wherein said method comprises a sparsity factor calculator configured to calculate, for each among the plurality of vectors, a value of a corresponding vector'"'"'s energy distribution, and

wherein, for each among the plurality of vectors, a corresponding bit allocation is based on a corresponding value of a corresponding vector'"'"'s energy distribution.

26. The apparatus for dynamic bit allocation according to claim 21, wherein said apparatus comprises a verification module configured to determine, for at least one among the plurality of vectors, that a corresponding bit allocation does not correspond to a valid codebook index length and to reduce a corresponding bit allocation in response to said determining.

27. The apparatus for dynamic bit allocation according to claim 21, wherein, for at least one among the plurality of vectors, a corresponding bit allocation is an index length of a codebook of patterns that each have n unit pulses, and said apparatus comprises a module configured to calculate a number of bits between a corresponding bit allocation and an index length of a codebook of patterns that each have (n+1) unit pulses.

28. The apparatus for dynamic bit allocation according to claim 21, wherein said apparatus comprises a normalizer configured to calculate, from each among the plurality of vectors, a corresponding gain factor and a corresponding shape vector.

29. The apparatus for dynamic bit allocation according to claim 21, wherein said apparatus comprises a frame divider configured to determine a length of each of the plurality of vectors,

wherein said determining a length of each of the plurality of vectors is based on locations of a second plurality of vectors, and

wherein a frame of an audio signal includes the plurality of vectors and the second plurality of vectors.

30. The apparatus for dynamic bit allocation according to claim 21, wherein the plurality of gain factors are calculated by dequantizing a corresponding quantized gain vector.

31. A non-transitory computer-readable storage medium having tangible features that cause an apparatus reading the features to:

calculate, for each among a plurality of vectors, a corresponding one of a plurality of gain factors;

calculate, for each among the plurality of vectors, a corresponding bit allocation that is based on a corresponding gain factor;

determine, for at least one vector among the plurality of vectors, that a corresponding bit allocation is not greater than a corresponding minimum allocation value, wherein each corresponding minimum allocation value is calculated based on a corresponding vector length and based on a value, wherein the value is the same for each of said at least one vector;

change a corresponding bit allocation, in response to said determining, for each of said at least one vector; and

encode each vector of the plurality of vectors into a corresponding allocated number of bits.