OCF--A new coding algorithm for high quality sound signals

An algorithm for calculating a noise-to-mask ratio is presented which helps to identify, where quantization noise could be audible, where the OCF-Coder can be audible.

Abstract

Optimum Coding in the Frequency domain (OCF) uses entropy coding of quantized spectral coefficients to efficiently code high quality sound signals with 3 bits/sample. In an iterative algorithm psychoacoustic weigthing is used to get the quantization noise to be masked in every critical band. The coder itself uses iterative quantizer control to get each data block to be coded with a fixed number of bits. Details about the OCF-Coder are presented together with information about the codebook needed and the training for the entropy coder. An algorithm for calculating a noise-to-mask ratio is presented which helps to identify, where quantization noise could be audible.