Patent ID: 8589151

Claim:
A method of transcoding Mixed Excitation Linear Prediction (MELP) encoded speech data, which comprises: quantizing MELP parameters for a block of voice data into quantized MELP parameters; encoding within an encoder circuit the quantized MELP parameters into a serial bit stream of encoded data having a first bit rate; converting the encoded data into MELP parameters; decoding the MELP parameters; buffering the decoded MELP parameters; generating perceptual inverse power spectrum weights using coefficients derived from line spectral frequencies and from the decoded MELP parameters; time interpolating the MELP parameters from frames of speech data using the inverse power spectrum weights; updating interpolation values as new MELP parameters if the number of speech frames exceeds a predetermined number and interpolating the new MELP parameters and iterating over the new MELP parameters; and encoding the interpolated data as a block of bits corresponding to frames of speech data and iterating to generate output speech samples having a second bit rate that is a multiple of the first bit rate, wherein the first and second bit rates are not the same.