METHODS AND APPARATUS FOR ENCODING AND CONSTRUCTING SIGNALS

摘要

A speech waveform is encoded to reduce storage capacity or transmission bandwidth requirements. The invention encodes two features of the time waveform, for example (1) duration of half-cycle, and (2) shape, e.g. number of maxima or minima of the waveform within that half cycle. The duration of each half cycle and the associated shape data constitute a pair of primary-code symbols. Each pair of primary code symbols may be represented by a single secondary code symbol using a mapping table. The number of secondary symbols may be reduced by grouping within the mapping table. Redundant sequences and inefficient transmission codes are deleted for further data reduction. Envelope peak value may be stuffed with the mapped signal for storage or transmission. Corresponding decoding provides speech synthesis.