Method and architecture of digital conding for transmitting and packing audio signals

Abstract

A method of digital coding transforms input audio signals into a sequence of frequency samples representing a spectral composition of the audio signals, and quantizes the sequence of frequency samples into quantized values according to a bit allocation process which uses a parameter predictor to evaluate quantization parameters by referring to a masking threshold. The quantized values are encoded into a number of bits of encoded data. An iterative rate control loop adjusts the quantization parameters and the quantization step size if the number of bits in the encoded data exceeds a prescribed number of bits available for the encoded data. The method may also cut off high frequency components of the input audio signals according to a cut-off frequency determined by the iterative rate control loop before quantizing the sequence of frequency samples.