Speech decoder with high-band generation and temporal envelope shaping

1. A speech decoding device for decoding an encoded speech signal, the speech decoding device comprising:

a processor configured to:

separate a bit stream that includes the encoded speech signal into an encoded bit stream and temporal envelope supplementary information, the bit stream received from outside the speech decoding device and the temporal envelope supplementary information comprising an indicator associated with a predetermined parameter;

decode the encoded bit stream to obtain a low frequency component;

transform the low frequency component into a spectral region;

generate a high frequency component by copying, from a low frequency band to a high frequency band, the low frequency component transformed into the spectral region;

adjust the high frequency component generated by the high frequency generating unit to generate an adjusted high frequency component;

analyze the low frequency component transformed into the spectral region to obtain temporal envelope information;

obtain the temporal envelope information by obtaining power of each quadrature mirror filter (QMF) subband sample of the low frequency component transformed into the spectral region;

convert the indicator included in the temporal envelope supplementary information into the predetermined parameter, wherein the predetermined parameter is for adjustment of the temporal envelope information;

adjust the temporal envelope information by adjusting the each QMF subband sample using the predetermined parameter to generate adjusted temporal envelope information; and

shape a temporal envelope of the adjusted high frequency component using the adjusted temporal envelope information.

2. The speech decoding device according to claim 1 , wherein the processor is further configured to obtain the temporal envelope information by normalization of the power of the each QMF subband sample by use of average power in an spectral band replication (SBR) envelope time segment.

3. A speech decoding device for decoding an encoded speech signal, the speech decoding device comprising:

a processor configured to:

decode a bit stream that includes the encoded speech signal to obtain a low frequency component, the bit stream received from outside the speech decoding device;

transform the low frequency component into a spectral region;

generate a high frequency component by copying the low frequency component, transformed into the spectral region, from a low frequency band to a high frequency band;

adjust the high frequency component to generate an adjusted high frequency component;

analyze the low frequency component transformed into the spectral region to obtain temporal envelope information;

obtain the temporal envelope information by obtaining a power value of each quadrature mirror filter (QMF) subband sample of the low frequency component transformed into the spectral region;

analyze the bit stream and extract an indicator included in the bit stream, the indicator associated with a predetermined parameter, the predetermined parameter for adjustment of the temporal envelope information;

generate the predetermined parameter for adjustment of the temporal envelope information by conversion of the indicator extracted from the bit stream into the predetermined parameter;

adjust the temporal envelope information by adjusting the each QMF subband sample using the predetermined parameter to generate adjusted temporal envelope information;

and

shape a temporal envelope of the adjusted high frequency component using the adjusted temporal envelope information.

4. The speech decoding device according to claim 3 , wherein the processor is further configured to obtain the temporal envelope information by normalization of the power of the each QMF subband sample by use of average power in an spectral band replication (SBR) envelope time segment.

5. A speech decoding method using a speech decoding device for decoding an encoded speech signal, the speech decoding method comprising:

a bit stream separating step in which the speech decoding device separates a bit stream that includes the encoded speech signal into an encoded bit stream and temporal envelope supplementary information, the bit stream received from outside the speech decoding device and the temporal envelope supplementary information comprising an indicator associated with a predetermined parameter;

a core decoding step in which the speech decoding device obtains a low frequency component by decoding the encoded bit stream separated in the bit stream separating step;

a frequency transform step in which the speech decoding device transforms the low frequency component obtained in the core decoding step into a spectral region;

a high frequency generating step in which the speech decoding device generates a high frequency component by copying the low frequency component transformed into the spectral region in the frequency transform step from a low frequency band to a high frequency band;

a high frequency adjusting step in which the speech decoding device adjusts the high frequency component generated in the high frequency generating step to generate an adjusted high frequency component;

a low frequency temporal envelope analysis step in which the speech decoding device obtains temporal envelope information by analyzing the low frequency component transformed into the spectral region in the frequency transform step, wherein the temporal envelope information is obtained by obtaining a power of each quadrature mirror filter (QMF) subband sample of the low frequency component transformed into the spectral region in the frequency transform step;

a supplementary information converting step in which the speech decoding device converts the indicator included in the temporal envelope supplementary information into the predetermined parameter, the predetermined parameter for adjusting the temporal envelope information;

a temporal envelope adjusting step in which the speech decoding device adjusts the temporal envelope information obtained in the low frequency temporal envelope analysis step by adjusting the each QMF subband sample to generate adjusted temporal envelope information, wherein the predetermined parameter is utilized in said adjusting of the temporal envelope information; and

a temporal envelope shaping step in which the speech decoding device shapes a temporal envelope of the adjusted high frequency component using the adjusted temporal envelope information.

6. A speech decoding method using a speech decoding device for decoding an encoded speech signal, the speech decoding method comprising:

a core decoding step in which the speech decoding device decodes a bit stream that includes the encoded speech signal to obtain a low frequency component, the bit stream received from outside the speech decoding device;

a frequency transform step in which the speech decoding device transforms the low frequency component obtained in the core decoding step into a spectral region;

a high frequency generating step in which the speech decoding device generates a high frequency component by copying the low frequency component transformed into the spectral region in the frequency transform step from a low frequency band to a high frequency band;

a high frequency adjusting step in which the speech decoding device adjusts the high frequency component generated in the high frequency generating step to generate an adjusted high frequency component;

a low frequency temporal envelope analysis step in which the speech decoding device obtains temporal envelope information by analyzing the low frequency component transformed into the spectral region in the frequency transform step, wherein the temporal envelope information is obtained by obtaining a power value of each quadrature mirror filter (QMF) subband sample of the low frequency component transformed into the spectral region in the frequency transform step;

a temporal envelope supplementary information generating step in which the speech decoding device analyzes the bit stream, extracts an indicator associated with a predetermined parameter, and converts the indicator into the predetermined parameter, wherein the predetermined parameter is for adjusting the temporal envelope information;

a temporal envelope adjusting step in which the speech decoding device adjusts the temporal envelope information obtained in the low frequency temporal envelope analysis step by adjusting the each QMF subband sample to generate adjusted temporal envelope information, wherein the predetermined parameter is utilized in said adjusting of the temporal envelope information; and

a temporal envelope shaping step in which the speech decoding device shapes a temporal envelope of the adjusted high frequency component using the adjusted temporal envelope information.

7. A non-transitory storage medium that stores instructions executable by a processor to decode an encoded speech signal, the storage medium comprising:

instructions executable by the processor to separate a bit stream that includes the encoded speech signal into an encoded bit stream and temporal envelope supplementary information, the temporal envelope supplementary information comprising an indicator associated with a predetermined parameter for adjusting the temporal envelope information;

instructions executable by the processor to decode the encoded bit stream to obtain a low frequency component;

instructions executable by the processor to transform the low frequency component into a spectral region;

instructions executable by the processor to generate a high frequency component by copying the low frequency component transformed into the spectral region from a low frequency band to a high frequency band;

instructions executable by the processor to adjust the high frequency component to generate an adjusted high frequency component;

instructions executable by the processor to analyze the low frequency component transformed into the spectral region to obtain temporal envelope information by determination of a power of each quadrature mirror filter (QMF) subband sample of the low frequency component transformed into the spectral region by the frequency transform means;

instructions executable by the processor to convert the indicator included in the temporal envelope supplementary information into the predetermined parameter for adjusting the temporal envelope information;

instructions executable by the processor to adjust the temporal envelope information by adjusting the each QMF subband sample to generate adjusted temporal envelope information using the predetermined parameter; and

instructions executable by the processor to shape a temporal envelope of the adjusted high frequency component using the adjusted temporal envelope information.

8. A non-transitory storage medium that stores instructions executable by a processor to decode an encoded speech signal, the storage medium comprising:

instructions executable by the processor to decode a bit stream that includes the encoded speech signal to obtain a low frequency component;

instructions executable by the processor to transform the low frequency component into a spectral region;

instructions executable by the processor to generate a high frequency component by copying the low frequency component transformed into the spectral region from a low frequency band to a high frequency band;

instructions executable by the processor to adjust the high frequency component to generate an adjusted high frequency component;

instructions executable by the processor to analyze the low frequency component transformed into the spectral region to obtain temporal envelope information by determination of a power value of each QMF subband sample of the low frequency component transformed into the spectral region;

instructions executable by the processor to analyze the bit stream, extract from the bit stream an indicator associated with a predetermined parameter, and convert the indicator to the predetermined parameter, the predetermined parameter for adjustment of the temporal envelope information;

instructions executable by the processor to adjust the temporal envelope information by adjusting the each QMF subband sample to generate adjusted temporal envelope information using the predetermined parameter; and

instructions executable by the processor to shape a temporal envelope of the adjusted high frequency component using the adjusted temporal envelope information.