Variable dimension spectral magnitude quantization apparatus and method using predictive and mel-scale binary vector

A residual spectral envelope quantization apparatus in a variable dimension spectral magnitude quantization apparatus, comprising:

• a predictive quantizer for obtaining a predictive-quantized first residual spectral envelope from a quantized previous residual spectral envelope;
• a mel-scale binary vector quantizer for obtaining a second residual spectral envelope represented with a linear scale code vector using a mel-scale binary vector codebook;
• and
• a residual spectral envelope quantizer for adding the output of the predictive quantizer and the output of the mel-scale binary vector quantizer to generate a quantized residual spectral envelope,
• wherein the mel-scale binary vector codebook is used for representing a residual spectral envelope of a variable high dimension as a code vector of a fixed low dimension.

A residual spectral envelope quantization method in variable dimension spectral magnitude quantization, comprising the steps of:

• (a) obtaining a predictive-quantized first residual spectral envelope from a quantized previous residual spectral envelope;
• (b) obtaining a second residual spectral envelope represented with a linear scale code vector using a mel-scale binary vector codebook;
• and
• (c) adding the first residual spectral envelope and the second residual spectral envelope to generate a quantized residual spectral envelope,
• wherein the mel-scale binary vector codebook is used for representing a residual spectral envelope of a variable high dimension as a code vector of a fixed low dimension.

A variable dimension spectral magnitude quantization method using low order linear prediction modeling and residual spectrum modeling according to linear prediction spectral envelope and residual spectral envelope quantization, the method comprising the steps of:

• (a) obtaining a predictive-quantized first residual spectral envelope from a quantized previous residual spectral envelope;
• (b) obtaining a second residual spectral envelope represented with a linear scale code vector using a mel-scale binary vector codebook;
• (c) adding the first residual spectral envelope and the second residual spectral envelope to generate a quantized residual spectral envelope and multiplying the quantized residual spectral envelope by a corresponding quantized linear prediction spectral envelope to generate a synthesized spectral envelope;
• (d) comparing the synthesized spectral envelope with an original spectral envelope;
• and
• (e) detecting a minimum value from the values sequentially obtained in the step (d).