ENCODING DEVICE AND ENCODING METHOD, DECODING DEVICE AND DECODING METHOD, AND PROGRAM
First Claim
1. An encoding device, comprising:
- a sub-band dividing unit configured to generate a low frequency sub-band signal of a sub-band on a low frequency side of an input signal and a high frequency sub-band signal of a sub-band on a high frequency side of the input signal;
a quasi-high frequency sub-band power calculating unit configured to calculate a quasi-high frequency sub-band power that is an estimated value of a high frequency sub-band power of the high frequency sub-band signal based on the low frequency sub-band signal and a predetermined estimation coefficient;
a feature amount calculating unit configured to calculate a number-of-sections determining feature amount based on at least one of the low frequency sub-band signal or the high frequency sub-band signal;
a determining unit configured to determine the number of continuous frame sections including frames for which the same estimation coefficient is selected in a process target section including a plurality of frames of the input signal, based on the number-of-sections determining feature amount;
a selecting unit configured to select the estimation coefficient of a frame that constitutes the continuous frame section from a plurality of estimation coefficients based on the quasi-high frequency sub-band power and the high frequency sub-band power in each continuous frame section obtained by dividing the process target section based on the determined number of continuous frame sections;
a generating unit configured to generate data for obtaining the estimation coefficient selected in a frame of each of the continuous frame sections constituting the process target section;
a low frequency encoding unit configured to encode a low frequency signal of the input signal to generate low frequency encoded data; and
a multiplexing unit configured to multiplex the data and the low frequency encoded data to generate an output code string.
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Abstract
The present technology relates to an encoding device and an encoding method, a decoding device and a decoding method, and a program, configured to obtain a high quality audio with less encoding amount. A number-of-sections determining feature amount calculating circuit calculates a number-of-sections determining feature amount for determining the number of divisions to divide a process target section into continuous frame sections each including a frame for which the same estimation coefficient is selected, based on sub-band signals of a plurality of sub-bands constituting an input signal. A quasi-high frequency sub-band power difference calculating circuit determines the number of continuous frame sections in the process target section based on the number-of-sections determining feature amount, selects an estimation coefficient for obtaining a high frequency component of the input signal by estimation for each continuous frame section, and generates data including a coefficient index for obtaining the estimation coefficient. A high frequency encoding circuit encodes the obtained data, and generates high frequency encoded data. The present technology can be applied to an encoding device.
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Citations
19 Claims
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1. An encoding device, comprising:
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a sub-band dividing unit configured to generate a low frequency sub-band signal of a sub-band on a low frequency side of an input signal and a high frequency sub-band signal of a sub-band on a high frequency side of the input signal; a quasi-high frequency sub-band power calculating unit configured to calculate a quasi-high frequency sub-band power that is an estimated value of a high frequency sub-band power of the high frequency sub-band signal based on the low frequency sub-band signal and a predetermined estimation coefficient; a feature amount calculating unit configured to calculate a number-of-sections determining feature amount based on at least one of the low frequency sub-band signal or the high frequency sub-band signal; a determining unit configured to determine the number of continuous frame sections including frames for which the same estimation coefficient is selected in a process target section including a plurality of frames of the input signal, based on the number-of-sections determining feature amount; a selecting unit configured to select the estimation coefficient of a frame that constitutes the continuous frame section from a plurality of estimation coefficients based on the quasi-high frequency sub-band power and the high frequency sub-band power in each continuous frame section obtained by dividing the process target section based on the determined number of continuous frame sections; a generating unit configured to generate data for obtaining the estimation coefficient selected in a frame of each of the continuous frame sections constituting the process target section; a low frequency encoding unit configured to encode a low frequency signal of the input signal to generate low frequency encoded data; and a multiplexing unit configured to multiplex the data and the low frequency encoded data to generate an output code string. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An encoding method, comprising the steps of:
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generating a low frequency sub-band signal of a sub-band on a low frequency side of an input signal and a high frequency sub-band signal of a sub-band on a high frequency side of the input signal; calculating a quasi-high frequency sub-band power that is an estimated value of a high frequency sub-band power of the high frequency sub-band signal based on the low frequency sub-band signal and a predetermined estimation coefficient; calculating a number-of-sections determining feature amount based on at least one of the low frequency sub-band signal or the high frequency sub-band signal; determining the number of continuous frame sections including frames for which the same estimation coefficient is selected in a process target section including a plurality of frames of the input signal, based on the number-of-sections determining feature amount; selecting the estimation coefficient of a frame that constitutes the continuous frame section from a plurality of estimation coefficients based on the quasi-high frequency sub-band power and the high frequency sub-band power in each continuous frame section obtained by dividing the process target section based on the determined number of continuous frame sections; generating data for obtaining the estimation coefficient selected in a frame of each of the continuous frame sections constituting the process target section; generating low frequency encoded data by encoding a low frequency signal of the input signal; and generating an output code string by multiplexing the data and the low frequency encoded data.
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12. A program configured to cause a computer to execute the steps of:
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generating a low frequency sub-band signal of a sub-band on a low frequency side of an input signal and a high frequency sub-band signal of a sub-band on a high frequency side of the input signal; calculating a quasi-high frequency sub-band power that is an estimated value of a high frequency sub-band power of the high frequency sub-band signal based on the low frequency sub-band signal and a predetermined estimation coefficient; calculating a number-of-sections determining feature amount based on at least one of the low frequency sub-band signal or the high frequency sub-band signal; determining the number of continuous frame sections including frames for which the same estimation coefficient is selected in a process target section including a plurality of frames of the input signal, based on the number-of-sections determining feature amount; selecting the estimation coefficient of a frame that constitutes the continuous frame section from a plurality of estimation coefficients based on the quasi-high frequency sub-band power and the high frequency sub-band power in each continuous frame section obtained by dividing the process target section based on the determined number of continuous frame sections; generating data for obtaining the estimation coefficient selected in a frame of each of the continuous frame sections constituting the process target section; generating low frequency encoded data by encoding a low frequency signal of the input signal; and generating an output code string by multiplexing the data and the low frequency encoded data.
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13. A decoding device, comprising:
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a demultiplexing unit configured to demultiplex an input code string into data for obtaining an estimation coefficient selected in a frame of each continuous frame section constituting a process target section, which is generated based on a result of calculating an estimated value of a high frequency sub-band power of a high frequency sub-band signal of an input signal based on a low frequency sub-band signal of the input signal and a predetermined estimation coefficient, determining the number of continuous frame sections including frames for which the same estimation coefficient is selected in the process target section including a plurality of frames of the input signal based on a number-of-sections determining feature amount extracted from the input signal, and selecting the estimation coefficient of a frame constituting the continuous frame section from a plurality of estimation coefficients based on the estimated value and the high frequency sub-band power in each of the continuous frame sections obtained by dividing the process target section based on the determined number of continuous frame sections, and low frequency encoded data obtained by encoding a low frequency signal of the input signal; a low frequency decoding unit configured to decode the low frequency encoded data to generate a low frequency signal; a high frequency signal generating unit configured to generate a high frequency signal based on the estimation coefficient obtained from the data and the low frequency signal obtained from the decoding; and a combining unit configured to generate an output signal based on the high frequency signal and the low frequency signal obtained from the decoding. - View Dependent Claims (14, 15, 16, 17)
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18. A decoding method, comprising the steps of:
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demultiplexing an input code string into data for obtaining an estimation coefficient selected in a frame of each continuous frame section constituting a process target section, which is generated based on a result of calculating an estimated value of a high frequency sub-band power of a high frequency sub-band signal of an input signal based on a low frequency sub-band signal of the input signal and a predetermined estimation coefficient, determining the number of continuous frame sections including frames for which the same estimation coefficient is selected in the process target section including a plurality of frames of the input signal based on a number-of-sections determining feature amount extracted from the input signal, and selecting the estimation coefficient of a frame constituting the continuous frame section from a plurality of estimation coefficients based on the estimated value and the high frequency sub-band power in each of the continuous frame sections obtained by dividing the process target section based on the determined number of continuous frame sections, and low frequency encoded data obtained by encoding a low frequency signal of the input signal; generating a low frequency signal by decoding the low frequency encoded data; generating a high frequency signal based on the estimation coefficient obtained from the data and the low frequency signal obtained from the decoding; and generating an output signal based on the high frequency signal and the low frequency signal obtained from the decoding.
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19. A program configured to cause a computer to execute the steps of:
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demultiplexing an input code string into data for obtaining an estimation coefficient selected in a frame of each continuous frame section constituting a process target section, which is generated based on a result of calculating an estimated value of a high frequency sub-band power of a high frequency sub-band signal of an input signal based on a low frequency sub-band signal of the input signal and a predetermined estimation coefficient, determining the number of continuous frame sections including frames for which the same estimation coefficient is selected in the process target section including a plurality of frames of the input signal based on a number-of-sections determining feature amount extracted from the input signal, and selecting the estimation coefficient of a frame constituting the continuous frame section from a plurality of estimation coefficients based on the estimated value and the high frequency sub-band power in each of the continuous frame sections obtained by dividing the process target section based on the determined number of continuous frame sections, and low frequency encoded data obtained by encoding a low frequency signal of the input signal; generating a low frequency signal by decoding the low frequency encoded data; generating a high frequency signal based on the estimation coefficient obtained from the data and the low frequency signal obtained from the decoding; and generating an output signal based on the high frequency signal and the low frequency signal obtained from the decoding.
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Specification