REW parametric vector quantization and dual-predictive SEW vector quantization for waveform interpolative coding
AssigneeThe Regents of the University of California
InventorsOded Gottesman, Allen Gersho
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Abstract
An enhanced analysis-by-synthesis waveform interpolative speech coder able to operate at 2.8 kbps. Novel features include dual-predictive analysis-by-synthesis quantization of the slowly-evolving waveform, efficient parametrization of the rapidly-evolving waveform magnitude, and analysis-by-synthesis vector quantization of the rapidly evolving waveform parameter. Subjective quality tests indicate that it exceeds G.723.1 at 5.3 kbps, and of G.723.1 at 6.3 kbps.
Claims8
A method for interpolative coding input signals, said signals decomposed into or composed of a slowly evolving waveform and a rapidly evolving waveform having a magnitude, the method incorporating at least one of the following steps:
- (a) analysis-by-synthesis vector quantization of the rapidly evolving waveform parameter;
- (b) parametrizing the magnitude of the rapidly evolving waveform;
- (c) incorporating temporal weighting in the AbS VQ of the REW;
- or
- (d) incorporating spectral weighting in the AbS VQ of the REW;
- the method either (1) applying a filter to a vector quantizer codebook in the analysis-by-synthesis vector-quantization of the rapidly evolving waveform whereby to add self correlation to the codebook vectors or (2) using a coder in which a plurality of bits therein are allocated to the rapidly evolving waveform magnitude.
A method for interpolative coding input signals, said signals decomposed into or composed of a slowly evolving waveform and a rapidly evolving waveform having a magnitude, comprising:
- (a) analysis-by-synthesis vector quantization of the rapidly evolving waveform parameter;
- (b) analysis-by-synthesis quantization of the slowly evolving waveform;
- (c) parametrizing the magnitude of the rapidly evolving waveform;
- (d) incorporating temporal weighting in the analysis-by-synthesis vector quantization of the rapidly evolving waveform;
- and
- (e) incorporating spectral weighting in the analysis-by-synthesis vector quantization of the rapidly evolving waveform
- the method either (1) applying a filter to a vector guantizer codebook in the analysis-by-synthesis vector-quantization of the rapidly evolving waveform whereby to add self correlation to the codebook vectors or (2) using a coder in which a plurality of bits therein are allocated to the rapidly evolving waveform magnitude.
A method for interpolative coding input signals, said signals decomposed into or composed of a rapidly evolving waveform, comprising incorporating analysis-by-synthesis vector quantization of the rapidly evolving waveform parameter, the method either (1) applying a filter to a vector guantizer codebook in the analysis-by-synthesis vector-quantization of the rapidly evolving waveform whereby to add self correlation to the codebook vectors or (2) using a coder in which a plurality of bits therein are allocated to the rapidly evolving waveform magnitude.
A speech coding system using waveform interpolation comprising at least one of the following steps:
- (a) analysis-by-synthesis vector quantization of a rapidly evolving waveform parameter;
- (b) parametrizing a magnitude of a rapidly evolving waveform;
- (c) incorporating temporal weighting in the AbS VQ of the REW;
- or
- (d) incorporating spectral weighting in the AbS VQ of the REW;
- the method either (1) applying a filter to a vector quantizer codebook in the analysis-by-synthesis vector-quantization of the rapidly evolving waveform whereby to add self correlation to the codebook vectors or (2) using a coder in which a plurality of bits therein are allocated to the rapidly evolving waveform magnitude.
Dependencies are inferred from the claim text.