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.
Claims18
A computerized system for coding a digital input signal representative of an audio waveform, comprising:
- a vector quantizer module comprising an input accepting a vector or rapidly evolving waveform spectra determined form the digital input signal;
- a computer readable codebook comprising a plurality of arrays of quantized parametric vectors;
- computer readable program instructions for searching said parameter codebook for one of said plurality of arrays of quantized parametric vectors which minimizes distortion;
- and
- computer program instructions for outputting a computer readable indicator that points to the one of said plurality of arrays of quantized parameter vectors which minimizes distortion.
A computer implemented method for coding a digital input signal representative of an audio waveform, comprising:
- determining a vector of rapidly evolving waveform spectra from the digital input signal;
- searching a computer readable codebook comprising a plurality of arrays of quantized parametric vector for one of said plurality of arrays of quantized parameter vectors which minimizes distortion;
- and
- outputting a computer readable indicator that points to the one of said plurality of arrays of quantized parameter vectors which minimizes said distortion.
Dependencies are inferred from the claim text.