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

摘要

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.

主权项

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 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.