Method for quantizing speech and audio through an efficient perceptually relevant search of multiple quantization patterns

• US 7,873,514 B2
• Filed: 08/07/2007
• Issued: 01/18/2011
• Est. Priority Date: 08/11/2006
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Ramprashad, Sean A.
• Primary Examiner(s): AZAD, ABUL K
• Application Number:
  US11/835,273
• Publication Number:
  US 20080040107A1
• Time in Patent Office: 1,260 Days
• Field of Search: 704/200.1, 704/222, 704/230
• US Class Current: 704/222
• CPC Class Codes: G10L 19/038 Vector quantisation, e.g. TwinVQ audio
• CPC Class Codes: G10L 2019/0005 Multi-stage vector quantisation

Abstract

A method and apparatus is disclosed herein for quantizing data using a perceptually relevant search of multiple quantization patterns. In one embodiment, the method comprises performing a perceptually relevant search of multiple quantization patterns in which one of a plurality of prototype patterns and its associated permutation are selected to quantize the target vector, each prototype pattern in the plurality of prototype patterns being capable of directing quantization across the vector; converting the one prototype pattern, the associated permutation and quantization information resulting from both to a plurality of bits by an encoder; and transferring the bits as part of a bit stream.

Claims

1. A method for quantizing a target vector comprising:

performing a perceptually relevant search of multiple quantization patterns in which one of a plurality of prototype patterns and its associated permutation are selected to quantize the target vector, each prototype pattern in the plurality of prototype patterns being capable of directing quantization across the vector;

converting the one prototype pattern, the associated permutation and quantization information resulting from both to a plurality of bits by an encoder; and

transferring the bits as part of a bit stream.

2. The method defined in claim 1 wherein performing the perceptually relevant search of multiple quantization patterns comprises

selecting a plurality of permutations of the plurality of prototype patterns;

and

selecting one of the plurality of prototype patterns and its associated permutation by searching the selected permutations using a distortion criterion.

3. The method defined in claim 2 wherein selecting the plurality of permutations of a plurality of prototype patterns is performed in an open loop manner.

4. The method defined in claim 2 wherein selecting the plurality of permutations of the plurality of prototype patterns is performed implicitly by re-ordering elements of the target vector into an ordering without reordering elements in each prototype pattern.

5. The method defined in claim 4 wherein the elements of the target vector are re-ordered based on energy into an ordering that is selected from a group consisting of a complete ordering and a loose ordering.

6. The method defined in claim 5 wherein the ordering is a partial ordering.

7. The method defined in claim 4 wherein the elements of the target vector are re-ordered based on perceptual relevance into an ordering that is selected from a group consisting of a complete ordering and a loose ordering.

8. The method defined in claim 7 wherein the ordering is a partial ordering.

9. The method defined in claim 1 wherein the one prototype pattern specifies a number of bits to be allocated to each element in the target vector during quantization.

10. The method defined in claim 1 wherein the one prototype pattern defines quantization step sizes to be allocated to each element in a vector during quantization.

11. The method defined in claim 1 wherein the one prototype pattern specifies a local dimension of a quantizer to perform the quantization.

12. The method defined in claim 11 wherein the local dimension indicates a number of elements in the target vector to be jointly quantized.

13. The method defined in claim 1 wherein each of the plurality of prototype quantization patterns has repeated elements that define equivalent quantization options.

14. The method defined in claim 1 wherein transferring the bits as part of a bit stream comprises transferring the bit stream to a decoder.

15. The method defined in claim 1 wherein transferring the bits as part of a bit stream comprises storing the bit stream in a memory.

16. An apparatus comprising:

a selector to perform a search of multiple quantization patterns and select, based on perceptually relevance, one of a plurality of prototype patterns and its associated permutation to quantize a target vector, each prototype pattern in the plurality of prototype patterns being capable of directing quantization across the vector; and

an encoder to convert the one prototype pattern, the associated permutation and quantization information resulting from both to a plurality of bits and to transfer the bits as part of a bit stream.

17. The apparatus defined in claim 16 wherein the selector selects a plurality of permutations of the plurality of prototype patterns and then selects one of the plurality of prototype patterns and its associated permutation by searching the selected permutations using a distortion criterion.

18. The apparatus defined in claim 17 wherein the selector selects the plurality of permutations of the plurality of prototype patterns implicitly by re-ordering elements of the target vector.

19. The apparatus defined in claim 16 wherein the one prototype pattern specifies one of a group consisting of a number of bits to be allocated to each element in the target vector during quantization, quantization step sizes to be allocated to each element in a vector during quantization, and a local dimension of a quantizer to perform the quantization.

20. An article of manufacture having one or more non-transitory computer readable media storing instructions thereon which, when executed by a system, cause the system to perform a method comprising:

performing a perceptually relevant search of multiple quantization patterns in which one of a plurality of prototype patterns and its associated permutation are selected to quantize the target vector, each prototype pattern in the plurality of prototype patterns being capable of directing quantization across the vector;

converting the one prototype pattern, the associated permutation and quantization information resulting from both to a plurality of bits by an encoder; and

transferring the bits as part of a bit stream.

21. The article of manufacture defined in claim 20 wherein performing the perceptually relevant search of multiple quantization patterns comprises

selecting a plurality of permutations of the plurality of prototype patterns;

and

selecting one of the plurality of prototype patterns and its associated permutation by searching the selected permutations using a distortion criterion.

22. A method for decompressing a bit stream comprising:

receiving the bit stream;

decoding bits in the bit stream;

recovering a quantized version of a parameter using a quantization pattern, a permutation and a quantization index identified by the decoded bits;

creating a quantized version of the target vector by reordering the quantization pattern and the permutation.