Frequency band extending device and method, encoding device and method, decoding device and method, and program
First Claim
1. An encoding device comprising:
- sub-band dividing means configured to divide an input signal into a plurality of sub-bands, and to generate a low frequency sub-band signal made up of a plurality of sub-bands at a low frequency side and a high frequency sub-band signal made up of a plurality of sub-bands at a high frequency side;
feature amount calculating means configured to calculate feature amount that expresses a feature of said input signal, using at least one of said low frequency sub-band signal generated by said sub-band dividing means, and said input signal;
pseudo high frequency sub-band power calculating means configured to calculate a pseudo high frequency sub-band power that is a pseudo power of said high frequency sub-band signal based on said feature amount calculated by said feature amount calculating means;
pseudo high frequency sub-band power difference calculating means configured to calculate a high frequency sub-band power that is the power of said high frequency sub-band signal from said high frequency sub-band signal generated by said sub-band dividing means, and to calculate pseudo high frequency sub-band power difference that is difference as to said pseudo high frequency sub-band power calculated by said pseudo high frequency sub-band power calculating means;
high frequency encoding means configured to encode said pseudo high frequency sub-band power difference calculated by said pseudo high frequency sub-band power difference calculating means to generate high frequency encoded data;
low frequency encoding means configured to encode a low frequency signal that is a low frequency signal of said input signal to generate low frequency encoded data; and
multiplexing means configured to multiplex said low frequency encoded data generated by said low frequency encoding means, and said high frequency encoded data generated by said high frequency encoding means to obtain an output code string.
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Abstract
The present invention relates to a frequency band extending device and method, an encoding device and method, a decoding device and method, and a program, whereby music signals can be played with higher sound quality due to the extension of frequency bands.
A bandpass filter 13 divides an input signal into multiple sub-band signals, a feature amount calculating circuit 14 calculates feature amount using at least one of the multiple divided sub-band signals and the input signal, a high frequency sub-band power estimating circuit 15 calculates an estimated value of a high frequency sub-band power based on the calculated feature amount, a high frequency signal generating circuit 16 generates a high frequency signal component based on the multiple sub-band signals divided by the bandpass filter 13, and the estimated value of the high frequency sub-band power calculated by the high frequency sub-band power estimating circuit 15. A frequency band extending device 10 extends the frequency band of the input signal using a high frequency signal component. The present invention may be applied to a frequency band extending device, for example.
196 Citations
10 Claims
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1. An encoding device comprising:
- sub-band dividing means configured to divide an input signal into a plurality of sub-bands, and to generate a low frequency sub-band signal made up of a plurality of sub-bands at a low frequency side and a high frequency sub-band signal made up of a plurality of sub-bands at a high frequency side;
feature amount calculating means configured to calculate feature amount that expresses a feature of said input signal, using at least one of said low frequency sub-band signal generated by said sub-band dividing means, and said input signal;
pseudo high frequency sub-band power calculating means configured to calculate a pseudo high frequency sub-band power that is a pseudo power of said high frequency sub-band signal based on said feature amount calculated by said feature amount calculating means;
pseudo high frequency sub-band power difference calculating means configured to calculate a high frequency sub-band power that is the power of said high frequency sub-band signal from said high frequency sub-band signal generated by said sub-band dividing means, and to calculate pseudo high frequency sub-band power difference that is difference as to said pseudo high frequency sub-band power calculated by said pseudo high frequency sub-band power calculating means;
high frequency encoding means configured to encode said pseudo high frequency sub-band power difference calculated by said pseudo high frequency sub-band power difference calculating means to generate high frequency encoded data;
low frequency encoding means configured to encode a low frequency signal that is a low frequency signal of said input signal to generate low frequency encoded data; and
multiplexing means configured to multiplex said low frequency encoded data generated by said low frequency encoding means, and said high frequency encoded data generated by said high frequency encoding means to obtain an output code string. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
- sub-band dividing means configured to divide an input signal into a plurality of sub-bands, and to generate a low frequency sub-band signal made up of a plurality of sub-bands at a low frequency side and a high frequency sub-band signal made up of a plurality of sub-bands at a high frequency side;
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9. An encoding method comprising:
- a sub-band dividing step arranged to divide an input signal into a plurality of sub-bands, and to generate a low frequency sub-band signal made up of a plurality of sub-bands at a low frequency side and a high frequency sub-band signal made up of a plurality of sub-bands at a high frequency side;
a feature amount calculating step arranged to calculate feature amount that expresses a feature of said input signal, using at least one of said low frequency sub-band signal generated by the processing in said sub-band dividing step, and said input signal;
a pseudo high frequency sub-band power calculating step arranged to calculate a pseudo high frequency sub-band power that is a pseudo power of said high frequency sub-band signal based on said feature amount calculated by the processing in said feature amount calculating step;
a pseudo high frequency sub-band power difference calculating step arranged to calculate a high frequency sub-band power that is the power of said high frequency sub-band signal from said high frequency sub-band signal generated by the processing in said sub-band dividing step, and to calculate pseudo high frequency sub-band power difference that is difference as to said pseudo high frequency sub-band power calculated by the processing in said pseudo high frequency sub-band power calculating step;
a high frequency encoding step arranged to encode said pseudo high frequency sub-band power difference calculated by the processing in said pseudo high frequency sub-band power difference calculating step to generate high frequency encoded data;
a low frequency encoding step arranged to encode a low frequency signal that is a low frequency signal of said input signal to generate low frequency encoded data; and
a multiplexing step arranged to multiplex said low frequency encoded data generated by the processing in said low frequency encoding step, and said high frequency encoded data generated by the processing in said high frequency encoding step to obtain an output code string.
- a sub-band dividing step arranged to divide an input signal into a plurality of sub-bands, and to generate a low frequency sub-band signal made up of a plurality of sub-bands at a low frequency side and a high frequency sub-band signal made up of a plurality of sub-bands at a high frequency side;
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10. A non-transitory computer-readable medium encoded with instructions which, when executed by a computer, cause the computer to execute processing comprising:
- a sub-band dividing step arranged to divide an input signal into a plurality of sub-bands, and to generate a low frequency sub-band signal made up of a plurality of sub-bands at a low frequency side and a high frequency sub-band signal made up of a plurality of sub-bands at a high frequency side;
a feature amount calculating step arranged to calculate feature amount that expresses a feature of said input signal, using at least one of said low frequency sub-band signal generated by the processing in said sub-band dividing step, and said input signal;
a pseudo high frequency sub-band power calculating step arranged to calculate a pseudo high frequency sub-band power that is a pseudo power of said high frequency sub-band signal based on said feature amount calculated by the processing in said feature amount calculating step;
a pseudo high frequency sub-band power difference calculating step arranged to calculate a high frequency sub-band power that is the power of said high frequency sub-band signal from said high frequency sub-band signal generated by the processing in said sub-band dividing step, and to calculate pseudo high frequency sub-band power difference that is difference as to said pseudo high frequency sub-band power calculated by the processing in said pseudo high frequency sub-band power calculating step;
a high frequency encoding step arranged to encode said pseudo high frequency sub-band power difference calculated by the processing in said pseudo high frequency sub-band power difference calculating step to generate high frequency encoded data;
a low frequency encoding step arranged to encode a low frequency signal that is a low frequency signal of said input signal to generate low frequency encoded data; and
a multiplexing step arranged to multiplex said low frequency encoded data generated by the processing in said low frequency encoding step, and said high frequency encoded data generated by the processing in said high frequency encoding step to obtain an output code string.
- a sub-band dividing step arranged to divide an input signal into a plurality of sub-bands, and to generate a low frequency sub-band signal made up of a plurality of sub-bands at a low frequency side and a high frequency sub-band signal made up of a plurality of sub-bands at a high frequency side;
Specification