Signal processing apparatus and signal processing method, encoder and encoding method, decoder and decoding method, and program

A signal processing method of a signal processing apparatus which includes

• 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 a coefficient table which is obtained based on the coefficient information among a plurality of coefficient tables used for the production of high band signals and having coefficients for the respective sub-bands on a high band side,
• an extension and reduction unit that deletes the coefficients of some sub-bands to reduce the coefficient table or produces the coefficients of predetermined sub-bands based on the coefficients of some sub-bands to extend the coefficient table,
• a high band sub-band power calculation unit that calculates high band sub-band powers of high band sub-band signals of the respective sub-bands constituting the high band signals based on low band sub-band signals of the respective sub-bands constituting the low band signals and the extended or reduced coefficient table, 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,
• the method comprising the steps of causing:
• the demultiplexing unit to demultiplex the encoded data;
• the low band decoding unit to produce the low band signals;
• the selection unit to select the coefficient table;
• the extension and reduction unit to reduce or extend the coefficient table;
• the high band sub-band power calculation unit to calculate the high band sub-band powers;
• and
• the high band signal production unit to produce the high band signals.

A non-transitory computer-readable medium having stored therein a program that comprises instructions for causing a computer to execute processes including the steps of:

• 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 a coefficient table which is obtained based on the coefficient information among a plurality of coefficient tables used for the production of high band signals and having coefficients for the respective sub-bands on a high band side;
• deleting the coefficients of some sub-bands to reduce the coefficient table or generating the coefficients of predetermined sub-bands based on the coefficients of some sub-bands to extend the coefficient table;
• calculating high band sub-band powers of high band sub-band signals of the respective sub-bands constituting the high band signals based on low band sub-band signals of the respective sub-bands constituting the low band signals and the extended or reduced coefficient table;
• and
• generating the high band signals based on the high band sub-band powers and the low band sub-band signals.

A signal processing apparatus comprising:

• a sub-band division unit that produces low band sub-band signals of a plurality of sub-bands on a low band side of an input signal and high band sub-band signals of a plurality of sub-bands on a high band side of the input signal;
• an extension and reduction unit that deletes the coefficients of some sub-bands to reduce a coefficient table or produces coefficients of predetermined sub-bands based on coefficients of some sub-bands to extend a coefficient table, the coefficient table having the coefficients for the respective sub-bands on the high band side;
• a pseudo high band sub-band power calculation unit that calculates pseudo high band sub-band powers, which are estimated values of powers of the high band sub-band signals, for the respective sub-bands on the high band side based on the extended or reduced coefficient table and the low band sub-band signals;
• a selection unit that compares high band sub-band powers of the high band sub-band signals and the pseudo high band sub-band powers to each other and selects one of a plurality of the coefficient tables;
• and
• a production unit that produces data containing coefficient information for obtaining the selected coefficient table.

A signal processing method of a signal processing apparatus which includes

• a sub-band division unit that produces low band sub-band signals of a plurality of sub-bands on a low band side of an input signal and high band sub-band signals of a plurality of sub-bands on a high band side of the input signal,
• an extension and reduction unit that deletes the coefficients of some sub-bands to reduce a coefficient table or produces coefficients of predetermined sub-bands based on coefficients of some sub-bands to extend a coefficient table, the coefficient table having coefficients for the respective sub-bands on the high band side,
• a pseudo high band sub-band power calculation unit that calculates pseudo high band sub-band powers, which are estimated values of powers of the high band sub-band signals, for the respective sub-bands on the high band side based on the extended or reduced coefficient table and the low band sub-band signals,
• a selection unit that compares high band sub-band powers of the high band sub-band signals and the pseudo high band sub-band powers to each other and selects one of a plurality of the coefficient tables, and
• a production unit that produces data containing coefficient information for obtaining the selected coefficient table,
• the method comprising the steps of causing:
• the sub-band division unit to produces the low band sub-band signals and the high band sub-band signals;
• the extension and reduction unit to reduce or extend the coefficient table;
• the pseudo high band sub-band power calculation unit to calculate the pseudo high band sub-band powers;
• the selection unit to select the coefficient table;
• and
• the production unit to produce the data containing coefficient information.

A non-transitory computer-readable medium having stored therein a program that comprises instructions for causing a computer to execute processes including the steps of:

• generating low band sub-band signals of a plurality of sub-bands on a low band side of an input signal and high band sub-band signals of a plurality of sub-bands on a high band side of the input signal;
• deleting the coefficients of some sub-bands to reduce a coefficient table or generating coefficients of predetermined sub-bands based on coefficients of some sub-bands to extend a coefficient table, the coefficient table having coefficients for the respective sub-bands on the high band side;
• calculating pseudo high band sub-band powers, which are estimated values of powers of the high band sub-band signals, for the respective sub-bands on the high band side based on the extended or reduced coefficient table and the low band sub-band signals;
• comparing high band sub-band powers of the high band sub-band signals and the pseudo high band sub-band powers to each other and selecting one of a plurality of the coefficient tables;
• and
• generating data containing coefficient information for obtaining the selected coefficient table.

A decoder comprising:

• 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 a coefficient table which is obtained based on the coefficient information among a plurality of coefficient tables used for the production of high band signals and having coefficients for the respective sub-bands on a high band side;
• an extension and reduction unit that deletes the coefficients of some sub-bands to reduce the coefficient table or produces the coefficients of predetermined sub-bands based on the coefficients of some sub-bands to extend the coefficient table;
• a high band sub-band power calculation unit that calculates high band sub-band powers of high band sub-band signals of the respective sub-bands constituting the high band signals based on low band sub-band signals of the respective sub-bands constituting the low band signals and the extended or reduced coefficient table;
• 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;
• and
• a synthesis unit that synthesizes the low band signal and the high band signal with each other to produce an output signal.

A decoding method of a decoder which includes

• 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 a coefficient table which is obtained based on the coefficient information among a plurality of coefficient tables used for the production of high band signals and having coefficients for the respective sub-bands on a high band side,
• an extension and reduction unit that deletes the coefficients of some sub-bands to reduce the coefficient table or produces the coefficients of predetermined sub-bands based on the coefficients of some sub-bands to extend the coefficient table,
• a high band sub-band power calculation unit that calculates high band sub-band powers of high band sub-band signals of the respective sub-bands constituting the high band signals based on low band sub-band signals of the respective sub-bands constituting the low band signals and the extended or reduced coefficient table,
• 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, and
• a synthesis unit that synthesizes the low band signal and the high band signal with each other to produce an output signal,
• the method comprising the steps of causing:
• the demultiplexing unit to demultiplex the encoded data;
• the low band decoding unit to produce the low band signals;
• the selection unit to select the coefficient table;
• the extension and reduction unit to reduce or extend the coefficient table;
• the high band sub-band power calculation unit to calculate the high band sub-band powers;
• the high band signal production unit to produce the high band signals;
• and
• the synthesis unit to produce the output signal.

An encoder comprising:

• a sub-band division unit that produces low band sub-band signals of a plurality of sub-bands on a low band side of an input signal and high band sub-band signals of a plurality of sub-bands on a high band side of the input signal;
• an extension and reduction unit that deletes the coefficients of some sub-bands to reduce a coefficient table or produces coefficients of predetermined sub-bands based on coefficients of some sub-bands to extend a coefficient table, the coefficient table having coefficients for the respective sub-bands on the high band side;
• a pseudo high band sub-band power calculation unit that calculates pseudo high band sub-band powers, which are estimated values of powers of the high band sub-band signals, for the respective sub-bands on the high band side based on the extended or reduced coefficient table and the low band sub-band signals;
• a selection unit that compares high band sub-band powers of the high band sub-band signals and the pseudo high band sub-band powers to each other and selects one of a plurality of the coefficient tables;
• a high band encoding unit that encodes coefficient information for obtaining the selected coefficient table to produce high band encoded data;
• a low band encoding unit that encodes low band signals of the input signal to produce low band encoded data;
• and
• a multiplexing unit that multiplexes the low band encoded data and the high band encoded data to produce an output code string.

An encoding method of an encoder which includes

• a sub-band division unit that produces low band sub-band signals of a plurality of sub-bands on a low band side of an input signal and high band sub-band signals of a plurality of sub-bands on a high band side of the input signal,
• an extension and reduction unit that deletes the coefficients of some sub-bands to reduce a coefficient table or produces coefficients of predetermined sub-bands based on coefficients of some sub-bands to extend a coefficient table, the coefficient table having coefficients for the respective sub-bands on the high band side,
• a pseudo high band sub-band power calculation unit that calculates pseudo high band sub-band powers, which are estimated values of powers of the high band sub-band signals, for the respective sub-bands on the high band side based on the extended or reduced coefficient table and the low band sub-band signals,
• a selection unit that compares high band sub-band powers of the high band sub-band signals and the pseudo high band sub-band powers to each other and selects one of a plurality of the coefficient tables,
• a high band encoding unit that encodes coefficient information for obtaining the selected coefficient table to produce high band encoded data,
• a low band encoding unit that encodes low band signals of the input signal to produce low band encoded data, and
• a multiplexing unit that multiplexes the low band encoded data and the high band encoded data to produce an output code string,
• the method comprising the steps of causing:
• the sub-band division unit to produces the low band sub-band signals and the high band sub-band signals;
• the extension and reduction unit to reduce or extend the coefficient table;
• the pseudo high band sub-band power calculation unit to calculate the pseudo high band sub-band powers;
• the selection unit to select the coefficient table;
• the high band encoding unit to produce the high band encoded data;
• the low band encoding unit to produce the low band encoded data;
• and
• the multiplexing unit to produce the output code string.