Patent ID: 6732071
Filing Date: 2004-05-04
Classification: G10L

Abstract:
A method comprising:receiving audio samples representing an input audio signal; transforming the input audio samples into a vector of spectral values in a frequency domain; and determining a value of a quantizing parameter that satisfies one or more criteria based, at least in part, on a modified Newtonian search process, the determined value of the quantizing parameter being used to quantize the respective vector of spectral values to generate a vector of quantized values, the value of the quantizing parameter being determined according to the following formula: global_gain&GreaterEqual;&LeftCeiling;A&CenterDot;log2&it;(MAX&it;&LeftBracketingBar;xr&it;(i)&RightBracketingBar;[B-C]D)&RightCeiling;wherein global gain corresponds to the value of the quantizing parameter, A corresponds to a first constant, xr(i) corresponds to an original spectral value for frequency line i, B corresponds to a second constant representing a maximum quantized spectral value, C corresponds to a third constant, and D corresponds to a fourth constant.