www.pudn.com > Matlab-MPEG.rar > Table_critical_band_boundaries.m, change:2007-08-21,size:1065b


function CB = Table_critical_band_boundaries(Layer, fs) 
%CB = Table_crital_band_boundaries(Layer, fs) 
% 
%   Return the index in the absolute threshold table for the critical band  
%   boundaries definied in [1, pp. 123] for Layer at sampling rate fs (Hz). 
% 
%   See also Table_absolute_threshold 
% 
%   References: 
%    [1] Information technology -- Coding of moving pictures and associated 
%        audio for digital storage media at up to 1,5 Mbits/s -- Part3: audio. 
%        British standard. BSI, London. October 1993. Implementation of ISO/IEC 
%        11172-3:1993. BSI, London. First edition 1993-08-01. 
% 
%------------------------------------------------------------------------------- 
 
% 第一层、采样率为44.1kHz的音信号 
if (Layer == 1) 
   if (fs == 44100) 
      % 24个临界带。 把20Hz-16kHz之间的频率分24个临界带 
      CB = [1, 2, 3, 5, 6, 8, 9, 11, 13, 15, 17, 20, 23, 27, 32, 37, 45, 50, 55, 61, 68, 75, 81, 93, 106]';  
    else 
       error('Frequency not supported.'); 
    end 
 else 
    error('Layer not supported.'); 
 end