| 摘要 |
<p>A method of encoding (14) an audio signal (x(n)) is disclosed. The method comprises the step of modelling (16) the audio signal in accordance with a frequency sensitizing parameter (() to provide a set of infinite impulse response (IIR) filter type characteristics ((0...k-1) of an order K and capable of being linearly combined with the sensitizing parameter (() to provide an estimate () for the audio signal (x(n)), the IIR type filter model satisfying the requirements of a minimum phase filter. The set of characteristics ((0...k-1) of order K are transformed as a function of the sensitizing parameter (() to provide a set of characteristics (c0...k) of order K+1 compatible with finite impulse response (FIR) filter type characteristics satisfying the requirements of a minimum phase filter. The set of characteristics (c0...k) of order K+1 are normalised to provide a set of characteristics (d1...k) of order K. An encoded audio stream (50) is generated to include representations (LAR,LSFs) of the normalised set of characteristics (d1...k) of order K.</p> |
