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

Patent metadata

Field	Value
Publication number	US-2016012829-A1
Application number	US-201514861734-A
Country	US
Kind code	A1
Filing date	Sep 22, 2015
Priority date	Oct 15, 2010
Publication date	Jan 14, 2016
Grant date	—

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.

First claim

1 - 16 . (canceled)

17 . 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 feature amount based on 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.

18 . 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.

19 . 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.

20 . 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.

Assignees

• Sony Corp

Inventors

• Yamamoto Yuki
• Chinen Toru

Classifications

• G10L21/04 Primary

  Time compression or expansion · CPC title

• G10L19/0208

  Subband vocoders · CPC title

• G10L25/21

  the extracted parameters being power information · CPC title

• G10L25/18

  the extracted parameters being spectral information of each sub-band · CPC title

• G10L19/02

  using spectral analysis, e.g. transform vocoders or subband vocoders · CPC title