Signal processing apparatus and signal processing method, encoder and encoding method, decoder and decoding method, and program
Methods and apparatus for performing signal processing. The signal processing comprises demultiplexing input encoded data into data including information for a segment including frames and coefficient information for a coefficient selected in the frames of the segment, and low band encoded data, decoding the low band encoded data to produce a low band signal, selecting a coefficient of a frame to be processed from a plurality of the coefficients based on the data, calculating a high band sub-band power of a high band sub-band signal of each sub-band constituting a high band signal of the frame to be processed based on a low band sub-band signal of each sub-band constituting the low band signal of the frame to be processed and the selected coefficient, and producing the high band signal of the frame to be processed based on the high band sub-band power and the low band sub-band signal.
1. A decoding device, comprising:
a demultiplexing circuit configured to demultiplex input encoded data into at least low frequency encoded data and an index indicating an estimating coefficient;
a low frequency decoding circuit configured to decode said low frequency encoded data to generate a low frequency signal;
a sub-band dividing circuit configured to divide a band of said low frequency signal into a plurality of low frequency sub-bands to generate a low frequency sub-band signal for each of said plurality of low frequency sub-bands; and
a generating circuit configured to generate a high frequency signal based on said index and said low frequency sub-band signals,
wherein said generating circuit comprises circuitry configured to:
calculate a plurality of feature amounts, each of which expresses a feature of said low frequency sub-band signal;
calculate a high frequency sub-band power of a high frequency sub-band signal of a high frequency sub-band using said feature amount and said estimating coefficient regarding each of a plurality of high frequency sub-bands making up a band of said high frequency signal; and
generate said high frequency signal based on said high frequency sub-band power and said low frequency sub-band signal;
wherein calculating said high frequency sub-band power of said high frequency sub-band comprises linearly combining the plurality of feature amounts, wherein said linearly combining comprises using said estimating coefficient prepared for each of said plurality of high frequency sub-bands.
2. A signal processing method, comprising:
demultiplexing input encoded data into at least low frequency encoded data and an index indicating an estimating coefficient;
decoding said low frequency encoded data to generate a low frequency signal;
dividing a band of said low frequency signal into a plurality of low frequency sub-bands to generate a low frequency sub-band signal for each of said low frequency sub-bands; and
generating a high frequency signal based on said index and said low frequency sub-band signals, wherein generating said high frequency signal comprises:
calculating a plurality of feature amounts, each of which expresses a feature of said low frequency sub-band signal;
calculating a high frequency sub-band power of a high frequency sub-band signal of a high frequency sub-band by using said feature amount and said estimating coefficient regarding each of a plurality of high frequency sub-bands making up a band of said high frequency signal; and
generating said high frequency signal based on said high frequency sub-band power and said low frequency sub-band signal;
wherein said calculating a high frequency sub-band power comprises calculating said high frequency sub-band power by linearly combining the plurality of calculated feature amounts, wherein said linearly combining comprises using said estimating coefficient prepared for each of said plurality of high frequency sub-bands.
3. A non-transitory computer readable medium encoded with a plurality of instructions that, when executed by at least one computer processor, perform a method comprising:
demultiplexing input encoded data into at least low frequency encoded data and an index indicating an estimating coefficient;
decoding said low frequency encoded data to generate a low frequency signal;
dividing a band of said low frequency signal into a plurality of low frequency sub-bands to generate a low frequency sub-band signal for each of said low frequency sub-bands; and
generating a high frequency signal based on said index and said low frequency sub-band signals, wherein generating said high frequency signal comprises:
calculating a plurality of feature amounts, each of which expresses a feature of said low frequency sub-band signal;
calculating a high frequency sub-band power of a high frequency sub-band signal of a high frequency sub-band by using said feature amount and said estimating coefficient regarding each of a plurality of high frequency sub-bands making up a band of said high frequency signal; and
generating said high frequency signal based on said high frequency sub-band power and said low frequency sub-band signal;
wherein said calculating a high frequency sub-band power comprises calculating said high frequency sub-band power by linearly combining the plurality of calculated feature amounts, wherein said linearly combining comprises using said estimating coefficient prepared for each of said plurality of high frequency sub-bands.