Audio quantization

• US 7,813,922 B2
• Filed: 01/30/2007
• Issued: 10/12/2010
• Est. Priority Date: 01/30/2007
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Laaksonen, Lasse, Vasilache, Adriana, Ramo, Anssi
• Primary Examiner(s): MCFADDEN, SUSAN IRIS
• Application Number:
  US11/700,732
• Publication Number:
  US 20080180307A1
• Time in Patent Office: 1,351 Days
• Field of Search: 704/230
• US Class Current: 704/230
• CPC Class Codes: G10L 19/032 Quantisation or dequantisation of spectral components

Abstract

For supporting a selection of a predictive or non-predictive quantization in the scope of an audio signal coding, it is determined whether an error resulting with a non-predictive quantization of an audio signal segment lies below a predetermined threshold value. An audio signal segment quantized with the non-predictive quantization is provided as a part of an encoded audio signal at least in case it is determined that the error resulting with the non-predictive quantization of the audio signal segment lies below a predetermined threshold value. Otherwise, an audio signal segment quantized with predictive quantization is provided as a part of an encoded audio signal.

Claims

1. A method comprising:

a processor of an electronic device;

determining whether an error resulting with a non-predictive quantization of parameters representing an audio signal segment lies below a predetermined threshold value;

providing parameters representing an audio signal segment quantized with said non-predictive quantization as a part of an encoded audio signal at least in case it is determined that said error resulting with said non-predictive quantization of said parameters representing an audio signal segment lies below a predetermined threshold value; and

providing otherwise parameters representing an audio signal segment quantized with predictive quantization as a part of an encoded audio signal.

2. The method according to claim 1, wherein said predetermined threshold is a threshold below which said error is considered to be inaudible.

3. The method according to claim 1, wherein said error is a spectral distortion over a frequency range between said original parameters representing an audio signal segment and parameters representing an audio signal segment resulting with said non-predictive quantization.

4. The method according to claim 1, wherein said error is obtained by combining weighted errors between a respective component of said parameters representing an audio signal segment and a corresponding component of said parameters representing an audio signal segment resulting with said non-predictive quantization.

5. The method according to claim 4, wherein said error is obtained by combining weighted mean square errors.

6. The method according to claim 4, wherein said weighting of errors is a psycho acoustically meaningful weighting.

7. The method according to claim 1, further comprising determining whether an error resulting with said non-predictive quantization of said parameters representing an audio signal segment is smaller than an error resulting with said predictive quantization of said parameters representing an audio signal segment, wherein parameters representing an audio signal segment quantized with said non-predictive quantization is provided in addition in case said error resulting with said non-predictive quantization of said parameters representing an audio signal segment is smaller than said error resulting with said predictive quantization of said parameters representing an audio signal segment.

8. The method according to claim 7, wherein at least one of said errors resulting with said non-predictive quantization and with said predictive quantization is weighted before determining whether said error resulting with said non-predictive quantization of said parameters representing an audio signal segment is smaller than said error resulting with said predictive quantization of said parameters representing an audio signal segment.

9. The method according to claim 1, further comprising determining whether a latest audio signal segment for which quantized parameters have been provided belongs to a sequence of audio signal segments for which parameters have been quantized with said predictive quantization, a number of said segments exceeding a predetermined number, wherein parameters representing an audio signal segment quantized with said non-predictive quantization is provided in addition in case it is determined that said number of segments for which parameters quantized with said predictive quantization have been provided in sequence exceeds said predetermined number.

10. An apparatus comprising:

at least one processing component; and

at least one memory including computer program code;

to the at least one memory and the computer program code configured to, with the at least one processing component, cause the apparatus at least to;

determine whether an error resulting with a non-predictive quantization of parameters representing an audio signal segment lies below a predetermined threshold value;

provide an audio signal segment quantized with said non-predictive quantization as a part of parameters representing an encoded audio signal at least in case it is determined that said error resulting with said non-predictive quantization of said parameters lies below a predetermined threshold value; and

provide otherwise parameters representing an audio signal segment quantized with predictive quantization as a part of an encoded audio signal.

11. The apparatus according to claim 10, wherein said predetermined threshold is a threshold below which said error is considered to be inaudible.

12. The apparatus according to claim 10, further comprising a processing component configured to compute said error as a spectral distortion over a frequency range between said original parameters representing an audio signal segment and parameters representing an audio signal segment resulting with said non-predictive quantization.

13. The apparatus according to claim 10, further comprising a processing component configured to compute said error by combining weighted errors between a respective component of said parameters representing an audio signal segment and a corresponding component of said parameters representing an audio signal segment resulting with said non-predictive quantization.

14. The apparatus according to claim 13, wherein said error is obtained by combining weighted mean square errors.

15. The apparatus according to claim 13, wherein said weighting of errors is a psycho acoustically meaningful weighting.

16. The apparatus according to claim 10, further comprising a processing component configured to determine whether an error resulting with said non-predictive quantization of said parameters representing an audio signal segment is smaller than an error resulting with said predictive quantization of said parameters representing an audio signal segment, wherein parameters representing an audio signal segment quantized with said non-predictive quantization is provided in addition in case said error resulting with said non-predictive quantization of said parameters representing an audio signal segment is smaller than said error resulting with said predictive quantization of said parameters representing an audio signal segment.

17. The apparatus according to claim 16, wherein at least one of said errors resulting with said non-predictive quantization and with said predictive quantization is weighted before determining whether said error resulting with said non-predictive quantization of said parameters representing an audio signal segment is smaller than said error resulting with said predictive quantization of said parameters representing an audio signal segment.

18. The apparatus according to claim 10, further comprising a processing component configured to determine whether a latest audio signal segment for which quantized parameters have been provided belongs to a sequence of audio signal segments for which parameters have been quantized with said predictive quantization, a number of said segments exceeding a predetermined number, wherein parameters representing an audio signal segment quantized with said non-predictive quantization are provided in addition in case it is determined that said number of segments for which parameters quantized with said predictive quantization have been provided in sequence exceeds said predetermined number.

19. An apparatus comprising:

means for determining whether an error resulting with a non-predictive quantization of parameters representing an audio signal segment lies below a predetermined threshold value;

means for providing parameters representing an audio signal segment quantized with said non-predictive quantization as a part of an encoded audio signal at least in case it is determined that said error resulting with said non-predictive quantization of said parameters representing audio signal segment lies below a predetermined threshold value; and

means for providing otherwise parameters representing an audio signal segment quantized with predictive quantization as a part of an encoded audio signal.

20. A non-transitory computer readable medium in which program code is stored, said program code realizing the following when executed by a processor:

determining whether an error resulting with a non-predictive quantization of parameters representing an audio signal segment lies below a predetermined threshold value;

providing parameters representing an audio signal segment quantized with said non-predictive quantization as a part of an encoded audio signal at least in case it is determined that said error resulting with said non-predictive quantization of said parameters representing an audio signal segment lies below a predetermined threshold value; and

providing otherwise parameters representing an audio signal segment quantized with predictive quantization as a part of an encoded audio signal.

21. The non-transitory computer readable medium according to claim 20, said program code further realizing:

determining whether a latest audio signal segment for which quantized parameters have been provided belongs to a sequence of audio signal segments for which parameters have been quantized with said predictive quantization, a number of said segments exceeding a predetermined number, wherein parameters representing an audio signal segment quantized with said non-predictive quantization is provided in addition in case it is determined that said number of audio signal segments for which parameters quantized with said predictive quantization have been provided in sequence exceeds said predetermined number.

22. The non-transitory computer readable medium according to claim 20, wherein said predetermined threshold is a threshold below which said error is considered to be inaudible.

23. The non-transitory computer readable medium according to claim 20, wherein said error is a spectral distortion over a frequency range between said original parameters representing an audio signal segment and parameters representing an audio signal segment resulting with said non-predictive quantization.

24. The non-transitory computer readable medium according to claim 20, wherein said error is obtained by combining weighted errors between a respective component of said original parameters representing an audio signal segment and a corresponding component of said parameters representing an audio signal segment resulting with said non-predictive quantization.

25. The non-transitory computer readable medium according to claim 24, wherein said error is obtained by combining weighted mean square errors.

26. The non-transitory computer readable medium according to claim 24, wherein said weighting of errors is a psycho acoustically meaningful weighting.

27. The non-transitory computer readable medium according to claim 20, said program code further realizing:

determining whether an error resulting with said non-predictive quantization of said parameters representing an audio signal segment is smaller than an error resulting with said predictive quantization of said parameters representing an audio signal segment, wherein parameters representing an audio signal segment quantized with said non-predictive quantization is provided in addition in case said error resulting with said non-predictive quantization of said parameters representing an audio signal segment is smaller than said error resulting with said predictive quantization of said parameters representing an audio signal segment.

28. The non-transitory computer readable medium according to claim 27, wherein at least one of said errors resulting with said non-predictive quantization and with said predictive quantization is weighted before determining whether said error resulting with said non-predictive quantization of said parameters representing an audio signal segment is smaller than said error resulting with said predictive quantization of said a parameters representing an audio signal segment.