| 摘要 |
A method and device for coding an input sound signal in at least one lower layer and at least one upper layer of an embedded codec while reducing a quantization noise comprises, in the at least one lower layer, coding the input sound signal to produce coding parameters, wherein coding the input sound signal comprises producing a synthesized sound signal. An error signal is computed as a difference between the input sound signal and the synthesized sound signal and a spectral mask is calculated as a function of a spectrum related to the input sound signal. In the at least one upper layer, the error signal is coded to produce coding coefficients, the spectral mask is applied to the coding coefficients, and the masked coding coefficients are quantized. Applying the spectral mask to the coding coefficients reduces the quantization noise produced upon quantizing the coding coefficients. Therefore, a method and device for reducing the quantization noise produced during coding of the error signal in the at least one upper layer comprises providing the spectral mask and, in the at least one upper layer, applying the spectral mask to the coding coefficients prior to quantizing the coding coefficients.
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