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US 2010/0250263 A1Published application
Method and apparatus for coding or decoding wideband speech
AssigneeKabushiki Kaisha Toshiba
InventorKimio MISEKI
Life of this patent
Estimating the term…
Abstract
A wideband speech coding method comprising identifying whether an input speech signal is a narrowband signal or a wideband signal, and coding the input speech signal by controlling a predetermined parameter of a wideband speech coding process based on the identification result.
Claims7
1-18. (canceled)
A wideband speech coding apparatus which causes an input speech signal to be represented by a spectrum parameter and an excitation signal, and codes the spectrum parameter and the excitation signal, the wideband speech coding apparatus comprising:
- a coding unit configured to select a plurality of pulses from given pulse position candidates, and to code the excitation signal with the selected pulses;
- an identification unit configured to identify whether the input speech signal is a wideband speech signal or a narrowband speech signal;
- a control unit configured to control the coding unit to select a pulse position candidate having a time resolution which is set in advance in accordance with the wideband speech signal, when the identification unit identifies that the input speech signal is the wideband speech signal, and to control the coding unit to lower the time resolution of the pulse position candidate, when the identification unit identifies that the input speech signal is the narrowband speech signal;
- a converter configured to convert a sampling rate of the input speech signal to a predetermined sampling rate for wideband speech coding;
- and
- an output unit to output a result of coding by the coding unit.
3 more elements
A wideband speech coding apparatus which causes an input speech signal to be represented by a spectrum parameter and an excitation signal, and codes the spectrum parameter and the excitation signal, the wideband speech coding apparatus comprising:
- a coding unit configured to select a plurality of pulses from given pulse position candidates, and coding the excitation signal with the selected pulses;
- an identification unit configured to identify whether a sampling rate of the input speech signal is a first sampling rate to be applied to the wideband speech signal or a second sampling rate to be applied to a narrowband speech signal;
- a control unit configured to control the coding unit to use a pulse position candidate having a time resolution which is set in advance in accordance with the first sampling rate, when the identification unit identifies that the sampling rate of the input speech signal is the first sampling rate, and to control the coding unit to lower the time resolution of the pulse position candidate, when the identification unit identifies that the sampling rate of the input speech signal is the second sampling rate;
- a converter configured to convert the sampling rate of the input speech signal to a predetermined sampling rate for wideband speech coding;
- and
- an output unit to output a result of coding by the coding unit.
3 more elements
A wideband speech coding method of causing an input speech signal to be represented by a spectrum parameter and an excitation signal, and then coding the spectrum parameter and the excitation signal, the wideband speech coding method comprising:
- a process of identifying whether the input speech signal is a wideband speech signal or a narrowband speech signal;
- a first coding process of preparing, when it is identified that the input speech signal is the wideband speech signal, pulse position candidates each having a time resolution which is set in advance in accordance with the wideband speech signal, and then coding the excitation signal with a plurality of pulses selected from the pulse position candidates;
- a second coding process of lowering, when it is identified that the input speech signal is the narrowband speech signal, the time resolution of the pulse position candidate, and then coding the excitation signal with a plurality of pulses selected from the pulse position candidates;
- a process of converting a sampling rate of the input speech signal to a predetermined sampling rate for wideband speech coding;
- and
- a process of outputting a result of coding in one of the first and second coding processes which is executed.
3 more elements
A wideband speech coding method of causing an input speech signal to be represented by a spectrum parameter and an excitation signal, and then coding the spectrum parameter and the excitation signal, the wideband speech coding method comprising:
- a process of identifying whether a sampling rate of the input speech signal is a first sampling rate to be applied to the wideband speech signal or a second sampling rate to be applied to a narrowband speech signal;
- a process of preparing, when it is identified that the sampling rate of the input speech signal is the first sampling rate, pulse position candidates each having a time resolution which is set in advance in accordance with the first sampling rate, and then coding the excitation signal with a plurality of pulses selected from the first pulse position candidates;
- a process of lowering, when it is identified that the sampling rate of the input speech signal is the second sampling rate, the time resolution of the pulse position candidate, and coding the excitation signal with a plurality of pulses selected from the second pulse position candidates;
- a process of converting the sampling rate of the input speech signal to a predetermined sampling rate for wideband speech coding;
- and
- a process of outputting a result of coding in one of the preparing and coding process and the lowering and coding process which is executed.
3 more elements
A wideband speech coding apparatus which causes an input speech signal to be represented by a spectrum parameter and an excitation signal, and codes the spectrum parameter and the excitation signal, the wideband speech coding apparatus comprising:
- adaptive codebook searching means for producing a first codevector corresponding to a pitch period of the input speech signal by using an adaptive codebook;
- noise codebook searching means for producing a second codevector by using a noise codebook comprising arrangement information regarding pulse position candidates, pulse polarity and the number of pulses;
- excitation signal producing means for producing an excitation signal by using the first codevector and the second codevector, and storing the excitation signal in the adaptive codebook;
- output means for outputting a code of the spectrum parameter coded by the spectrum parameter coding means, a code corresponding to the first codevector produced by the adaptive codebook searching means, and a code corresponding to the second codevector produced by the noise codebook searching means;
- and
- identification means for identifying whether the input speech signal is a wideband speech signal or a narrowband speech signal,
- wherein the noise codebook searching means modifies arrangement information of the noise codebook, such that when the identification means identifies that the input speech signal is the wideband speech signal, the noise codebook searching means produces the second codevector having a first number of pulses, and when the identification means identifies that the input speech signal is the narrowband speech signal, the noise codebook searching means produces the second codevector having a second number of pulses which is larger than the first number of pulses.
4 more elements
A wideband speech coding method which causes an input speech signal to be represented by a spectrum parameter and an excitation signal, and codes the spectrum parameter and the excitation signal, the wideband speech coding apparatus comprising:
- a spectrum parameter coding process of extracting a spectrum parameter from the input speech signal, and coding the extracted spectrum parameter;
- an adaptive codebook searching process of producing a first codevector corresponding to a pitch period of the input speech signal by using an adaptive codebook;
- a noise codebook searching process of producing a second codevector by using a noise codebook comprising arrangement information regarding pulse position candidates, pulse polarity and the number of pulses;
- a producing process of producing an excitation signal by using the first codevector and the second codevector;
- a storing process of storing the excitation signal in the adaptive codebook;
- an outputting process of outputting a code of the spectrum parameter coded in the spectrum parameter coding process, a code corresponding to the first codevector produced in the adaptive code searching process, and a code corresponding to the second codevector produced in the noise code book searching process;
- and
- an identification process of identifying whether the input speech signal is a wideband speech signal or a narrowband speech signal,
- wherein in the noise codebook searching process, arrangement information of the noise codebook is modified, such that when it is identified in the identification process that the input speech signal is the wideband speech signal, the second codevector is produced in such a manner as to have a first number of pulses, and when it is identified in the identification process that the input speech signal is the narrowband speech signal, the second codevector having a second number of pulses is produced, the second number of plusses being larger than the first number of pulses.
6 more elements
Dependencies are inferred from the claim text.