Encoding device and method, decoding device and method, and program

• US 9,767,824 B2
• Filed: 11/21/2016
• Issued: 09/19/2017
• Est. Priority Date: 10/15/2010
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Yamamoto, Yuki, Chinen, Toru
• Primary Examiner(s): TON, DAVID L
• Application Number:
  US15/357,877
• Publication Number:
  US 20170076737A1
• Time in Patent Office: 302 Days
• Field of Search: 381 22, 381 23, 381 98, 704500, 704501
• CPC Class Codes: G10L 19/008 Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing
• CPC Class Codes: G10L 19/0208 Subband vocoders
• CPC Class Codes: G10L 21/0388 Details of processing therefor
• CPC Class Codes: G10L 25/18 the extracted parameters being spectral information of each sub-band
• CPC Class Codes: G10L 25/21 the extracted parameters being power information

Abstract

The present invention relates to an encoding device and method, and a decoding device and method, and a program which enable music signals to be played with higher sound quality by expanding a frequency band.

A band pass filter divides an input signal into multiple subband signals, a feature amount calculating circuit calculates feature amount using at least any one of the divided multiple subband signals and the input signal, a high-frequency subband power estimating circuit calculates an estimated value of high-frequency subband power based on the calculated feature amount, and a high-frequency signal generating circuit generates a high-frequency signal component based on the multiple subband signals divided by the band pass filter and the estimated value of the high-frequency subband power calculated by the high-frequency subband power estimating circuit. A frequency band expanding device expands the frequency band of the input signal using the high-frequency signal component generated by the high-frequency signal generating circuit. The present invention may be applied to a frequency band expanding device, encoding device, decoding device, and so forth, for example.

Claims

1. A decoding device comprising:

a demultiplexing circuit configured to demultiplex input encoded data into low-frequency encoded data, coefficient information for obtaining a coefficient, and smoothing information relating to smoothing;

a low-frequency decoding circuit configured to decode the low-frequency encoded data to generate a low-frequency signal;

a subband dividing circuit configured to divide the low-frequency signal into a plurality of subbands to generate a low-frequency subband signal for each of the subbands;

a feature amount calculating circuit configured to calculate a feature amount based on the low-frequency subband signals, wherein the feature amount includes low-frequency subband powers of the low-frequency subband signals;

a smoothing circuit configured to subject the feature amount to smoothing by performing weighted averaging on the feature amount of a predetermined number of continuous frames of the low-frequency signal based on the smoothing information; and

a generating circuit configured to generate a high-frequency signal based on the coefficient obtained from the coefficient information, the feature amount subjected to smoothing, and the low-frequency subband signals.

2. The decoding device according to claim 1, wherein the smoothing information is information indicating at least one of the number of frames used for the weighted averaging, or weight used for the weighted averaging.

3. The decoding device according to claim 1, wherein the generating circuit includes

decoded high-frequency subband power calculating circuit configured to calculate decoded high-frequency subband power that is an estimated value of subband power included in the high-frequency signal based on the smoothed feature amount and the coefficient, and

high-frequency signal generating circuit configured to generate the high-frequency signal based on the decoded high-frequency subband power and the low-frequency subband signal.

4. The decoding device according to claim 1, wherein the coefficient is generated by learning with the feature amount obtained from a broadband supervisory signal, and power of the same subband as a subband included in the high-frequency signal of the broadband supervisory signal, as an explanatory variable and an explained variable.

5. A decoding method comprising:

demultiplexing, by processing circuitry, input encoded data into low-frequency encoded data, coefficient information for obtaining a coefficient, and smoothing information related to smoothing;

decoding, by the processing circuitry, the low-frequency encoded data to generate a low-frequency signal;

dividing, by the processing circuitry, the low-frequency signal into a plurality of subbands to generate a low-frequency subband signal for each of the subbands;

calculating, by the processing circuitry, a feature amount based on the low-frequency subband signals, wherein the feature amount includes low-frequency subband powers of the low-frequency subband signals;

subjecting, by the processing circuitry, the feature amount to smoothing by performing weighted averaging on the feature amount of a predetermined number of continuous frames of the low-frequency signal based on the smoothing information; and

generating, by the processing circuitry, a high-frequency signal based on the coefficient obtained from the coefficient information, the feature amount subjected to smoothing, and the low-frequency subband signals.

6. A computer-readable storage device encoded with computer-executable instructions that, when executed by processing circuitry, perform a decoding method comprising:

demultiplexing input encoded data into low-frequency encoded data, coefficient information for obtaining a coefficient, and smoothing information related to smoothing;

decoding the low-frequency encoded data to generate a low-frequency signal;

dividing the low-frequency signal into a plurality of subbands to generate a low-frequency subband signal for each of the subbands;

calculating a feature amount based on the low-frequency subband signals, wherein the feature amount includes low-frequency subband powers of the low-frequency subband signals;

subjecting the feature amount to smoothing by performing weighted averaging on the feature amount of a predetermined number of continuous frames of the low-frequency signal based on the smoothing information; and

generating a high-frequency signal based on the coefficient obtained from the coefficient information, the feature amount subjected to smoothing, and the low-frequency subband signals.