ENCODING DEVICE AND ENCODING METHOD, DECODING DEVICE AND DECODING METHOD, AND PROGRAM

摘要

The present technology relates to an encoding device and an encoding method, a decoding device and a decoding method, and a program, configured to obtain a high quality audio with less encoding amount. A number-of-sections determining feature amount calculating circuit calculates a number-of-sections determining feature amount for determining the number of divisions to divide a process target section into continuous frame sections each including a frame for which the same estimation coefficient is selected, based on sub-band signals of a plurality of sub-bands constituting an input signal. A quasi-high frequency sub-band power difference calculating circuit determines the number of continuous frame sections in the process target section based on the number-of-sections determining feature amount, selects an estimation coefficient for obtaining a high frequency component of the input signal by estimation for each continuous frame section, and generates data including a coefficient index for obtaining the estimation coefficient. A high frequency encoding circuit encodes the obtained data, and generates high frequency encoded data. The present technology can be applied to an encoding device.

主权项

1. An encoding device, comprising:
a sub-band dividing unit configured to generate a low frequency sub-band signal of a sub-band on a low frequency side of an input signal and a high frequency sub-band signal of a sub-band on a high frequency side of the input signal; a quasi-high frequency sub-band power calculating unit configured to calculate a quasi-high frequency sub-band power that is an estimated value of a high frequency sub-band power of the high frequency sub-band signal based on the low frequency sub-band signal and a predetermined estimation coefficient; a feature amount calculating unit configured to calculate a number-of-sections determining feature amount based on at least one of the low frequency sub-band signal or the high frequency sub-band signal; a determining unit configured to determine the number of continuous frame sections including frames for which the same estimation coefficient is selected in a process target section including a plurality of frames of the input signal, based on the number-of-sections determining feature amount; a selecting unit configured to select the estimation coefficient of a frame that constitutes the continuous frame section from a plurality of estimation coefficients based on the quasi-high frequency sub-band power and the high frequency sub-band power in each continuous frame section obtained by dividing the process target section based on the determined number of continuous frame sections; a generating unit configured to generate data for obtaining the estimation coefficient selected in a frame of each of the continuous frame sections constituting the process target section; a low frequency encoding unit configured to encode a low frequency signal of the input signal to generate low frequency encoded data; and a multiplexing unit configured to multiplex the data and the low frequency encoded data to generate an output code string.