Bandwidth extension mode selection

Patent metadata

Field	Value
Publication number	US-9293143-B2
Application number	US-201414270963-A
Country	US
Kind code	B2
Filing date	May 6, 2014
Priority date	Dec 11, 2013
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

A device includes a decoder that includes an extractor, a predictor, a selector, and a switch. The extractor is configured to extract a first plurality of parameters from a received input signal. The input signal corresponds to an encoded audio signal. The predictor is configured to perform blind bandwidth extension by generating a second plurality of parameters independent of high band information in the input signal. The second plurality of parameters corresponds to a high band portion of the encoded audio signal. The selector is configured to select a particular mode from multiple high band modes including a first mode using the first plurality of parameters and a second mode using the second plurality of parameters. The switch is configured to output the first plurality of parameters or the second plurality of parameters based on the selected particular mode.

First claim

What is claimed is:

1. A device comprising:
a decoder including:
an extractor configured to extract a first plurality of parameters from a received input signal, wherein the input signal corresponds to an encoded audio signal;
a predictor configured to perform blind bandwidth extension by generating a second plurality of parameters independent of high band information in the input signal, wherein the second plurality of parameters corresponds to a high band portion of the encoded audio signal, wherein the second plurality of parameters is generated based on low band parameter information corresponding to low band parameters in the input signal, and wherein the low band parameters are associated with a low band portion of the encoded audio signal;
a selector configured to select a particular mode from multiple high band modes for reproduction of the high band portion of the encoded audio signal, the multiple high band modes including a first mode using the first plurality of parameters and a second mode using the second plurality of parameters; and
a switch configured to output the first plurality of parameters or the second plurality of parameters based on the selected particular mode.

2. The device of claim 1 , wherein the input signal corresponds to an input bit stream and wherein the extractor is configured to extract the first plurality of parameters concurrently with the predictor generating the second plurality of parameters.

3. The device of claim 1 , wherein the selector is further configured to receive a control input signal, wherein the particular mode is selected based on the control input signal.

4. The device of claim 1 , wherein the extractor is configured to extract the first plurality of parameters embedded within the low band parameter information in the input signal.

5. The device of claim 1 , wherein the extractor is configured to detect a watermark in the input signal, the watermark encoding the first plurality of parameters.

6. The device of claim 1 , wherein the extractor is further configured to extract error detection data associated with the first plurality of parameters.

7. The device of claim 6 , further comprising:
an error detector coupled to the extractor and to the selector, the error detector configured to:
receive the error detection data; and
generate an error output based on the error detection data,

wherein the selector is configured to select the particular mode at least partially based on the error output.

8. The device of claim 7 , further comprising:
a parameter validity checker configured to generate validity data indicating reliability of the first plurality of parameters,
wherein the validity data is based at least in part on the first plurality of parameters and the second plurality of parameters, and
wherein the selector is configured to select the particular mode based on the validity data.

9. The device of claim 8 , wherein the selector is configured to select the first mode using the first plurality of parameters in response to determining that the validity data satisfies a reliability threshold and that the error output indicates that an error is not detected.

10. The device of claim 9 , wherein the selector is further configured to select the second mode using the second plurality of parameters in response to determining that the validity data does not satisfy a reliability threshold or that the error output indicates that the error is detected.

11. The device of claim 9 , wherein the selector is further configured to select a third mode of the multiple high band modes in response to determining that the validity data does not satisfy a reliability threshold or that the error output indicates that the error is detected and wherein the switch is configured to output no high band parameters in response to determining that the third mode is selected.

12. The device of claim 1 , wherein the decoder is an enhanced adaptive multi-rate (eAMR) decoder.

13. The device of claim 1 , wherein the predictor comprises:
a blind bandwidth extender configured to perform the blind bandwidth extension to generate the second plurality of parameters based on analysis data; and
a tuner configured to modify the analysis data based at least in part on the first plurality of parameters.

14. The device of claim 1 , wherein the first plurality of parameters includes at least one of line spectral frequencies (LSF), gain shape, or gain frame.

15. The device of claim 1 , wherein the predictor is configured to generate the second plurality of parameters based on a predicted gain frame.

16. The device of claim 15 , wherein the predictor is further configured to adjust the predicted gain frame based on a ratio of a first gain frame of the first plurality of parameters and a second gain frame of the second plurality of parameters.

17. The device of claim 1 , wherein the predictor is configured to generate the second plurality of parameters based on average line spectral frequencies (LSF).

18. The device of claim 17 , wherein the predictor is further configured to adjust the average LSF based on a first LSF of the first plurality of parameters.

19. The device of claim 1 , further comprising an output generator configured to:
generate an output low band portion based on the low band parameters;
generate an output high band portion based on the particular mode; and
generate an output signal by combining the output low band portion and the output high band portion.

20. A method comprising:
extracting, at a decoder, a first plurality of parameters from a received input signal, wherein the input signal corresponds to an encoded audio signal;
performing, at the decoder, blind bandwidth extension by generating a second plurality of parameters independent of high band information in the input signal, wherein the second plurality of parameters corresponds to a high band portion of the encoded audio signal, wherein the second plurality of parameters is generated based on low band parameter information corresponding to low band parameters in the input signal, and wherein the low band parameters are associated with a low band portion of the encoded audio signal;
selecting, at the decoder, a particular mode from multiple high band modes for reproduction of the high band portion of the encoded audio signal, the multiple high band modes including a first mode using the first plurality of parameters and a second mode using the second plurality of parameters; and
sending the first plurality of parameters or the second plurality of parameters to an output generator of the decoder in response to selection of the particular mode.

21. The method of claim 20 , wherein the second plurality of parameters is selected in response to detecting an error associated with the first plurality of parameters.

22. The method of claim 21 , wherein the error is detected in response to determining that a cyclic redundancy check (CRC) associated with the first plurality of parameters indicates invalid data.

23. The method of claim 20 , wherein the decoder is an enhanced adaptive multi-rate (eAMR) decoder.

24. A computer-readable storage device storing instructions that, when executed by a processor, cause the processor to perform operations comprising:
extracting a first plurality of parameters from a received input signal, wherein the input signal corresponds to an encoded audio signal;
performing blind bandwidth extension by generati

Assignees

• Qualcomm Inc

Inventors

• Villette Stephane Pierre
• Sinder Daniel J

Classifications

• G10L19/00 Primary

  Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis (in musical instruments G10H) · CPC title

• G10L19/005

  Correction of errors induced by the transmission channel, if related to the coding algorithm · CPC title

• G10L21/038

  using band spreading techniques · CPC title

• G10L19/008 Primary

  Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing · CPC title

• G10L19/24 Primary

  Variable rate codecs, e.g. for generating different qualities using a scalable representation such as hierarchical encoding or layered encoding · CPC title