DECODER FOR AUDIO SIGNAL INCLUDING GENERIC AUDIO AND SPEECH FRAMES

• US 20110218799A1
• Filed: 09/09/2010
• Published: 09/08/2011
• Est. Priority Date: 03/05/2010
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Gibbs, Joanthan A., Ashley, James P., Mittal, Udar
• Granted Patent: US 8,428,936 B2
• Time in Patent Office: Days
• US Class Current: 704/203
• CPC Class Codes: G10L 19/0212 using orthogonal transformation
• CPC Class Codes: G10L 19/12 the excitation function being a code excitation, e.g. in code excited linear prediction [CELP] vocoders
• CPC Class Codes: G10L 19/18 Vocoders using multiple modes
• CPC Class Codes: G10L 19/20 using sound class specific coding, hybrid encoders or object based coding

Abstract

A method for decoding audio frames includes producing a first frame of coded audio samples, producing at least a portion of a second frame of coded audio samples, generating audio gap filler samples based on parameters representative of a weighted segment of the first frame of coded audio samples or a weighted segment of the portion of the second frame of coded audio samples, and forming a sequence including the audio gap filler samples and the portion of the second frame of coded audio samples.

Claims

1. A method for decoding audio frames, the method comprising:

producing, using a first decoding method, a first frame of coded audio samples;

producing, using a second decoding method, at least a portion of a second frame of coded audio samples;

generating audio gap filler samples based on parameters representative of a weighted segment of the first frame of coded audio samples or a weighted segment of the portion of the second frame of coded audio samples,

forming a sequence including the audio gap filler samples and the portion of the second frame of coded audio samples.

2. The method of claim 1 further comprising forming the sequence including the first frame of coded audio samples, wherein the audio gap filler samples at least partially fill an audio gap between the first frame of coded audio samples and the portion of the second frame of coded audio samples.

3. The method of claim 1, wherein

the weighted segment of the first frame of coded audio samples includes a first weighting parameter and a first index for the weighted segment of the first frame of coded audio samples, and

the weighted segment of the portion of the second frame of coded audio samples includes a second weighting parameter and a second index for the weighted segment of the portion of the second frame of coded audio samples.

4. The method of claim 3, wherein

the first index specifying a first time offset from the audio gap filler sample to a corresponding sample in the first frame of coded audio samples,

the second index specifying a second time offset from the audio gap filler sample to a corresponding sample in the portion of the second frame of coded audio samples.

5. The method of claim 1, generating the audio gap filler samples based on parameters representative of both the weighted segment of the first frame of coded audio samples and the weighted segment of the portion of the second frame of coded audio samples.

6. The method of claim 5, wherein the parameters are based on an expression:

ŝ

_g=α

·

ŝ

_s(−

T₁)+β

·

ŝ

_a(T₂)

wherein α

is a first weighting factor of a segment of the first frame of coded audio samples ŝ

_s(−

T₁), β

is a second weighting factor for a segment of the portion of the second frame of coded audio samples ŝ

_a(T₂), and ŝ

_g corresponds to the audio gap filler samples.

7. The method of claim 6, wherein the parameters are based on a distortion metric that is a function of a set of reference audio gap samples, wherein the distortion metric is a squared error distortion metric.

8. The method of claim 6, wherein the parameters are based on a distortion metric that is a function of a set of reference audio gap samples, wherein the distortion metric is based on an expression:

D=|s_g−

ŝ

_g|^T·

|s_g−

ŝ

_g|

where s_g is representative of the set of reference gap filler samples.

9. The method of claim 6, producing the portion of the second frame of coded audio samples using a generic audio coding method.

10. The method of claim 9, producing the first frame of coded audio samples using a speech coding method.

11. The method of claim 1, wherein the parameters are based on a distortion metric that is a function of a set of the reference gap filler samples.

12. The method of claim 1, producing the portion of the second frame of coded audio samples using a generic audio coding method.

13. The method of claim 12, producing the first frame of coded audio samples using a speech coding method.

14. The method of claim 3, wherein

the first index is based on a correlation between a segment of the first frame of coded audio samples and a segment of reference audio gap samples in the sequence of frames, and

the second index is based on a correlation between a segment of the portion of the second frame of coded audio samples and the segment of reference audio gap samples.

15. The method of claim 1, generating the audio gap filler samples based on parameters selected to reduce distortion between the audio gap filler samples and a set of reference audio gap samples.