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US 7,065,338 B2Granted
Method, device and program for coding and decoding acoustic parameter, and method, device and program for coding and decoding sound
AssigneesNippon Telegraph and Telephone Corporation, Matsushita Electric Industrial Co., Ltd.
InventorsKazunori Mano, Yusuke Hiwasaki, Hiroyuki Ehara, Kazutoshi Yasunaga
Life of this patent
Estimating the term…
Abstract
In coding and decoding an acoustic parameter, a weighted vector is generated by multiplying a code vector output in a past frame and a code vector selected in a present frame by weighting factors respectively selected from a factor code book and adding the products to each other.
Claims49
An acoustic parameter coding method, comprising:
- (a) a step of calculating an acoustic parameter equivalent to a linear predictive coefficient showing a spectrum envelope characteristic of an acoustic signal for every frame of a predetermined length of time;
- (b) a step of multiplying a code vector outputted in at least one frame in the closest past selected from a vector codebook for storing a plurality of code vectors in correspondence with an index representing said code vectors and a code vector selected in a current frame respectively with a set of weighting coefficients selected from a coefficient codebook for storing one or more sets of weighting coefficients in correspondence with an index representing the weighting coefficients, wherein multiplied results are added to generate a weighted vector and a vector including a component of said weighted vector is found as a candidate of a quantized acoustic parameter with respect to said acoustic parameter of the current frame;
- and
- (c) a step of determining the code vector of the vector codebook and the set of the weighting coefficients of the coefficient codebook by using a standard such that a distortion of said candidate of the quantized acoustic parameter with respect to the calculated acoustic parameter becomes a minimum, wherein an index showing the determined code vector and the determined set of the weighting coefficients are determined and outputted as a quantized code of the acoustic parameter.
1 more element
An acoustic parameter decoding method, comprising:
- (a) a step of outputting a code vector corresponding to an index expressed by a code inputted for every frame and a set of weighting coefficients from a vector codebook and a coefficient codebook, said vector codebook storing a plurality of code vectors of an acoustic parameter equivalent to a linear predictive coefficient showing a spectrum envelope characteristic of an acoustic signal in correspondence with an index representing the code vectors, said coefficient codebook storing one or more sets of weighting coefficients in correspondence with an index representing said sets;
- and
- (b) a step of multiplying said code vector outputted from said vector codebook in at least one frame of the closest past and a code vector outputted from the vector codebook in a current frame respectively with said outputted set of the weighting coefficients, and adding multiplied results together to thereby generate a weighted vector, wherein a vector including a component of said weighted vector is outputted as a decoded quantized vector of the current frame.
An acoustic parameter coding device, comprising:
- parameter calculating means for analyzing an input acoustic signal for every frame and calculating an acoustic parameter equivalent to a linear predictive coefficient showing a spectrum envelope characteristic of the acoustic signal;
- a vector codebook for storing a plurality of code vectors in correspondence with an index representing the vectors;
- a coefficient codebook for storing one or more sets of weighting coefficients in correspondence with an index representing the coefficients;
- quantized parameter generating means for multiplying a code vector with respect to a current frame outputted from the vector codebook and a code vector outputted in at least one frame of the closest past respectively with the set of the weighting coefficients selected from the coefficient codebook, said quantized parameter generating means adding results together a vector including a component of the generated weighted vector as a candidate of a quantized acoustic parameter with respect to the acoustic parameter in the current frame;
- a distortion computing part for computing a distortion of the quantized acoustic parameter with respect to the acoustic parameter calculated at the parameter calculating means;
- and
- a codebook search controlling part for determining the code vector of the vector codebook and the set of the weighting coefficients of the coefficient codebook by using a standard such that the distortion becomes small, said codebook search controlling part outputting indexes respectively representing the determined code vector and the set of the weighting coefficients as codes of the acoustic parameter.
4 more elements
An acoustic parameter decoding device, comprising:
- a vector codebook for storing a plurality of code vectors of an acoustic parameter equivalent to a linear predictive coefficient showing a spectrum envelope characteristic of an acoustic signal in correspondence with an index representing the code vectors,
- a coefficient codebook for storing one or more sets of weighting coefficients in correspondence with an index representing the weighting coefficients, and
- quantized parameter generating means for outputting one code vector from the vector codebook in correspondence with an index showing a code inputted for every frame, to thereby output a set of weighting coefficients from said coefficient codebook, said quantized parameter generating means multiplying the code vector outputted in a current frame and a code vector outputted in at least one frame of the closest past respectively with the set of the weighting coefficients outputted in the current frame, said quantized parameter generating means adding multiplied results together to thereby generate a weighted vector, said quantized parameter generating means outputting a vector including a component of the generated weighted vector as a decoded quantized acoustic parameter of the current frame.
Dependencies are inferred from the claim text.