Patent ID: 8515742

Claim:
A method of transmitting an input audio signal, the method comprising: encoding a first coding error of the input audio signal with a scalable codec having a first enhancement layer; encoding a second coding error by using a second enhancement layer after the first enhancement layer, encoding the second coding error comprising coding fine spectrum coefficients of the second coding error to produce coded fine spectrum coefficients, and coding a spectral envelope of the second coding error to produce a coded spectral envelope; transmitting the coded fine spectrum coefficients and the coded spectral envelope; wherein: the first coding error and the second coding error are in a same band; the first coding error represents a distortion of an output of an inner core layer codec; and the first coding error is a weighted difference between an original reference input and a decoded output of the inner core layer codec; and the second coding error is a weighted difference between a quantized output of the first enhancement layer and unquantized coefficients of the first coding error.