Methods and apparatus for reconstructing non-quantized adaptively transformed voice signals

摘要

Reconstructing adaptively transformed voice signals is done using noise shaping (110) to scale the spectral envelope (98) before generating the bit allocation (111). Generating discrete cosine transform coefficients (80) is accomplished by determining from the bit allocation (111) to which of the transform coefficients (80) no bits were allocated, retrieving the spectral envelope information (98) corresponding to the transform coefficients (80) to which no bits are allocated and substituting each item of spectral envelope information (98) into the block of quantized (82) transform coefficients (80) after each item has been given a sign and scaled. $$