Encoding device and decoding device
First Claim
Patent Images
1. An encoding device comprising:
- a time characteristic extracting unit for specifying a band of an audio input signal that is to be encoded in the time domain based on a characteristic of the audio input signal, and for outputting data indicating the specified band;
a time-frequency transforming unit for transforming the audio input signal into a frequency spectrum according to a time-frequency transformation, and for outputting a first part of the frequency spectrum and a second part of the frequency spectrum, the second part of the frequency spectrum corresponding to the specified band;
a time transforming unit for transforming the second part of the frequency spectrum into a time-frequency signal according to a frequency-time transformation; and
an encoding unit for encoding the first part of the frequency spectrum obtained from the time-frequency transforming unit and the time-frequency signal obtained from the time transforming unit, and for generating the encoded first part of the frequency spectrum and the encoded time-frequency signal as an output signal.
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Abstract
An encoding device (200) includes: a time characteristic extracting unit (203) that specifies a band for a part of a frequency spectrum based on a characteristic of an audio input signal in a time domain; a time transforming unit (204) that transforms a signal in the specified band to a signal according to frequency-time transform; and an encoded data stream generating unit (205) that encodes the signal obtained by the time transforming unit (204) and at least a part of the frequency spectrum, and generates an output encoded data stream from the encoded signal and the encoded frequency spectrum.
30 Citations
25 Claims
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1. An encoding device comprising:
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a time characteristic extracting unit for specifying a band of an audio input signal that is to be encoded in the time domain based on a characteristic of the audio input signal, and for outputting data indicating the specified band; a time-frequency transforming unit for transforming the audio input signal into a frequency spectrum according to a time-frequency transformation, and for outputting a first part of the frequency spectrum and a second part of the frequency spectrum, the second part of the frequency spectrum corresponding to the specified band; a time transforming unit for transforming the second part of the frequency spectrum into a time-frequency signal according to a frequency-time transformation; and an encoding unit for encoding the first part of the frequency spectrum obtained from the time-frequency transforming unit and the time-frequency signal obtained from the time transforming unit, and for generating the encoded first part of the frequency spectrum and the encoded time-frequency signal as an output signal. - View Dependent Claims (2, 3)
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4. An encoding device comprising:
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a time characteristic extracting unit for specifying one or more bands of an audio input signal that is to be encoded in the time domain based on a characteristic of the input signal, and for outputting data indicating the specified bands; a time-frequency transforming unit for transforming the audio input signal into a frequency spectrum according to a time-frequency transformation, and for outputting the frequency spectrum; a reference band deciding unit for deciding a reference band and a target band from among the specified bands, the reference band being utilized to compose the target band, and for outputting a part of the frequency spectrum which corresponds to the specified bands including the reference band and the target band; a time transforming unit for transforming a part of the frequency spectrum into a time-frequency signal according to a frequency-time transformation; a time composing and encoding unit for generating a parameter to compose a time-frequency signal for the reference band, and for encoding the parameter and data indicating the target band and the reference band; an encoding unit for encoding a part of the frequency spectrum obtained from the time-frequency transforming unit, and for outputting an encoded frequency spectrum; and an encoded data stream generating unit for generating an encoded data stream including the encoded frequency spectrum obtained from the encoding unit, encoded data indicating the target band and the reference band obtained from the time composing and encoding unit, and data indicating the specified bands output from the time characteristic extracting unit. - View Dependent Claims (5, 6, 7)
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8. An encoding device comprising:
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a time characteristic extracting unit for specifying a band of an audio input signal that is to be encoded in the time domain based on a characteristic of the input signal, for outputting data indicating the specified band; a time-frequency transforming unit operable for transforming the audio input signal into a frequency spectrum according to a time-frequency transformation, and for outputting a first part of the frequency spectrum and a second part of the frequency spectrum, the second part of the frequency spectrum corresponding to the specified band; a frequency characteristic extracting unit for specifying a third part of the frequency spectrum from the first part of the frequency spectrum obtained by the time-frequency transforming unit that is to be encoded in the time domain based on a characteristic of the first part of the frequency spectrum, for outputting data indicating the specified third part of the frequency spectrum, and for outputting an unspecified part of the first part of the frequency spectrum; a time transforming unit for transforming a signal of the second part and the third part of the frequency spectrum into a time-frequency signal according to the frequency-time transformation; and an encoding unit for encoding the unspecified part of the first part of the frequency spectrum obtained from the frequency characteristic extracting unit and the time-frequency signal obtained from the time transforming unit, and for generating the encoded unspecified part of the first part of the frequency spectrum and the encoded time-frequency signal as an output signal. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A decoding device for decoding encoded data of an encoded data stream obtained by encoding an audio input signal, said decoding device comprising:
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a decoding unit for extracting a first part of the encoded data from the encoded data stream and a second part of the encoded data from the encoded data stream, for decoding the first part of the encoded data to generate a first part of a frequency spectrum, and for decoding the second part of the encoded data to generate a time-frequency signal; a frequency transforming unit for tramsforming the time-frequency signal generated by said decoding unit into a second part of the frequency spectrum; and a frequency-time transforming unit for composing the first part of the frequency spectrum and the second part of the frequency spectrum, and for transforming the composed frequency spectrum into an audio output signal in the time domain. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22)
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23. An encoding method comprising:
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a time characteristic extracting step of specifying a band of an audio input signal that is to be encoded in the time domain based on a characteristic of the audio input original signal, and outputting data indicating the specified band; a time-frequency transforming step of transforming the audio input signal into a frequency spectrum according to a time-frequency transformation, and outputting a first part of the frequency spectrum and a second part of the frequency spectrum, the second part of the frequency spectrum corresponding to the specified band; a time transforming step of transforming the second part of the frequency spectrum into a time-frequency signal according to a frequency-time transformation; and an encoding step of encoding the first part of the frequency spectrum obtained by the time-frequency transforming step and the time-frequency signal obtained by the time transforming step, and generating the encoded first part of the frequency spectrum and the encoded time-frequency signal as an output signal.
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24. A decoding method for decoding encoded data of an encoded data stream obtained by encoding an audio input signal, said decoding method comprising:
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a decoding step of extracting a first part of the encoded data from the encoded data stream and a second part of the encoded data from the encoded data stream, decoding the first part of the encoded data to generate a first part of a frequency spectrum, and decoding the second part of the encoded data to generate a time-frequency signal; a frequency transforming step of transforming the time-frequency signal generated by said decoding step into a second part of the frequency spectrum; and a frequency-time transforming step of composing the first part of the frequency spectrum and the second part of the frequency spectrum, and transforming the composed frequency spectrum into an audio output signal in the time domain.
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25. An encoding method comprising:
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a time characteristic extracting step of specifying a band of an audio input signal that is to be encoded in the time domain based on a characteristic of the input signal, and outputting data indicating the specified band; a time-frequency transforming step of transforming the audio input signal into a frequency spectrum according to a time-frequency transformation, and outputting a first part of the frequency spectrum and a second part of the frequency spectrum, the second part of the frequency spectrum corresponding to the band specified by the time characteristic extracting unit; a frequency characteristic extracting step of specifying a third part of the frequency spectrum from the first part of the frequency spectrum obtained by the time-frequency transforming unit that is to be encoded in the time domain based on a characteristic of the first part of the frequency spectrum, outputting data indicating the specified third part of the frequency spectrum, and outputting an unspecified part of the first part of the frequency spectrum; a time transforming step of transforming a signal of the second part and the third part of the frequency spectrum into a time-frequency signal according to the frequency-time transformation; and an encoding step of encoding the unspecified part of the first part of the frequency spectrum obtained from the frequency characteristic extracting unit and the time-frequency signal obtained from the time transforming unit, and generating the encoded unspecified part of the first part of the frequency spectrum and the encoded time-frequency signal as an output signal.
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Specification