Audio quantization

• US 20080180307A1
• Filed: 01/30/2007
• Published: 07/31/2008
• 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
• Granted Patent: US 7,813,922 B2
• Time in Patent Office: Days
• US Class Current: 341/200
• 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:

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

providing 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 audio signal segment lies below a predetermined threshold value; and

providing otherwise 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 audio signal segment and 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 audio signal segment and a corresponding component of said 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 audio signal segment is smaller than an error resulting with said predictive quantization of said audio signal segment, wherein 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 audio signal segment is smaller than said error resulting with said predictive quantization of said 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 audio signal segment is smaller than said error resulting with said predictive quantization of said audio signal segment.

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

10. An apparatus comprising:

a processing component configured to determine whether an error resulting with a non-predictive quantization of an audio signal segment lies below a predetermined threshold value;

a processing component configured to provide 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 audio signal segment lies below a predetermined threshold value; and

a processing component configured to provide otherwise 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 audio signal segment and 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 audio signal segment and a corresponding component of said 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 audio signal segment is smaller than an error resulting with said predictive quantization of said audio signal segment, wherein 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 audio signal segment is smaller than said error resulting with said predictive quantization of said 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 audio signal segment is smaller than said error resulting with said predictive quantization of said audio signal segment.

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

19. An electronic device comprising:

an apparatus according to claim 10; and

an audio input component.

20. A system comprising:

an apparatus according to claim 10; and

an apparatus comprising a processing component configured to decode an encoded audio signal provided by said apparatus according to claim 10.

21. A computer program product in which a program code is stored in a computer readable medium, said program code realizing the following when executed by a processor:

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

providing 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 audio signal segment lies below a predetermined threshold value; and

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

22. The computer program product according to claim 21, wherein said predetermined threshold is a threshold below which said error is considered to be inaudible.

23. The computer program product according to claim 21, wherein said error is a spectral distortion over a frequency range between said original audio signal segment and an audio signal segment resulting with said non-predictive quantization.

24. The computer program product according to claim 21, wherein said error is obtained by combining weighted errors between a respective component of said original audio signal segment and a corresponding component of said audio signal segment resulting with said non-predictive quantization.

25. The computer program product according to claim 24, wherein said error is obtained by combining weighted mean square errors.

26. The computer program product according to claim 24, wherein said weighting of errors is a psycho acoustically meaningful weighting.

27. The computer program product according to claim 21, said program code further realizing:

determining whether an error resulting with said non-predictive quantization of said audio signal segment is smaller than an error resulting with said predictive quantization of said audio signal segment, wherein 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 audio signal segment is smaller than said error resulting with said predictive quantization of said audio signal segment.

28. The computer program product 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 audio signal segment is smaller than said error resulting with said predictive quantization of said audio signal segment.

29. The computer program product according to claim 21, said program code further realizing:

determining whether a latest provided quantized audio signal segment belongs to a sequence of audio signal segments quantized with said predictive quantization, a number of said segments exceeding a predetermined number, wherein 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 quantized with said predictive quantization that has been provided in sequence exceeds said predetermined number.

30. An apparatus comprising:

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

means for providing 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 audio signal segment lies below a predetermined threshold value; and

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