SIGNAL PROCESSING APPARATUS AND SIGNAL PROCESSING METHOD, ENCODER AND ENCODING METHOD, DECODER AND DECODING METHOD, AND PROGRAM
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Abstract
The present invention relates to a signal processing apparatus and a signal processing method, an encoder and an encoding method, a decoder and a decoding method, and a program capable of reproducing music signal having a better sound quality by expansion of frequency band.
A high band decoding circuit decodes high band encoded data outputs a coefficient table having coefficients for the respective high band sub-bands, which are specified by a coefficient index obtained as a result of decoding. A decoding high band sub-band power calculation circuit calculates decoded high band sub-band powers for the respective high band sub-bands based on low band signals and the coefficient table, and a decoded high band signal production unit produces decoded high band signals from these decoded high band sub-band powers. At this time, an extension and reduction unit newly produces or deletes coefficients of the coefficient table for the respective sub-bands to correspond to the number of sub-bands of the calculated decoded high band sub-band powers, thereby to extend or reduce the coefficient table. The present invention can be applied to a decoder.
29 Citations
29 Claims
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1-14. -14. (canceled)
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15. A decoder comprising:
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a demultiplexing unit that demultiplexes input encoded data to at least low band encoded data and coefficient information; a low band decoding unit that decodes the low band encoded data to produce low band signals; a selection unit that selects coefficients based on the coefficient information for the production of high band signals; a high band sub-band power calculation unit that calculates high band sub-band powers of high band sub-band signals constituting the high band signals based on low band sub-band signals constituting the low band signals and the coefficients, wherein the coefficient for a sub-band having a highest frequency is used for at least another sub-band in the high band sub-band power calculation unit; and a high band signal production unit that produces the high band signals based on the high band sub-band powers and the low band sub-band signals. - View Dependent Claims (16, 17, 18, 19)
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20. A decoding method of a decoder, comprising:
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demultiplexing input encoded data to at least low band encoded data and coefficient information; decoding the low band encoded data to produce low band signals; selecting coefficients based on the coefficient information for the production of high band signals; calculating high band sub-band powers of high band sub-band signals constituting the high band signals based on low band sub-band signals constituting the low band signals and the coefficients, wherein the coefficient for a sub-band having a highest frequency is used for at least another sub-band in the high band sub-band power calculation unit; and producing the high band signals based on the high band sub-band powers and the low band sub-band signals. - View Dependent Claims (21, 22, 23, 24)
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25. A non-transitory computer-readable medium having stored therein a program that comprises instructions for causing a computer to execute processes including:
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demultiplexing input encoded data to at least low band encoded data and coefficient information; decoding the low band encoded data to produce low band signals; selecting coefficients based on the coefficient information for the production of high band signals; calculating high band sub-band powers of high band sub-band signals constituting the high band signals based on low band sub-band signals constituting the low band signals and the coefficients, wherein the coefficient for a sub-band having a highest frequency is used for at least another sub-band in the high band sub-band power calculation unit; and producing the high band signals based on the high band sub-band powers and the low band sub-band signals. - View Dependent Claims (26, 27, 28, 29)
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Specification