VECTOR QUANTIZATION OF A TIME SEQUENTIAL SIGNAL BY QUANTIZING AN ERROR BETWEEN SUBFRAME AND INTERPOLATED FEATURE VECTORS

摘要

For quantization of subframe feature vectorsrepresentative of subframes identified by subframeindexes in each frame of a time sequential signal, suchas an audio or a video signal, a first feature vector ofa first subframe of a current frame is extracted withadditional extraction of a second feature vector of asecond subframe of the current frame and is quantized bya frame vector quantizer unit into a quantized framevector for the current frame. Using a quantized framevector for a previous frame and referring tointerpolation coefficient vectors, an interpolatorinterpolates an interpolated feature vector for thecurrent frame. An error vector is calculated between theinterpolated and the second feature vectors and isquantized by an error vector quantizer unit into aquantized error vector. The subframe feature vectors arequantized by using the subframe indexes, the quantizedframe vectors, the interpolated feature vector, and thequantized error vector. Preferably, the interpolationcoefficient vectors are adjusted according to a modedecided for the current frame by its subframes.