ExtensionActs as a spectral filter.
| buffer | 
 The FFT buffer to filter.  | 
| specBuffer | 
 The FFT buffer to derive the spectral curve from.  | 
| floor | 
 The spectral curve is a normalized representation of the magnitudes in specBuffer (between 0 and 1). if floor > 0, mags in the spectral curve BELOW this number are also zeroed out.  | 
| freeze | 
 If > 0, freeze the current spectral curve. The 'floor' parameter is ignored once the spectral curve is frozen.  | 
| mode | 
 If mode == 0, PV_SpectralMap does not have any effect. > 0 acts as a bandpass filter, < 0 a bandreject.  | 
| norm | 
 Normalization mode. If <=0, the specBuffer's magnitudes are normalized on a frame by from basis. >0, normalized according to the the sum of the FFT window's sample values.  | 
| window | 
 The window used for the FFT - this will effect scaling if norm is > 0.  |