www.pudn.com > Matlab-MPEG.rar > Minimum_masking_threshold.m, change:2007-08-21,size:1095b


function  LTmin = Minimum_masking_threshold(LTg, Map) 
%   LTmin = Minimum_masking_threshold(LTg, Map) 
% 
%   为每个子频带,寻找最小的全局掩蔽阈值 
%   Find the minimum of the global masking threshold for each subband. 
%   [1, pp. 114] 
% 
%   See also Global_masking_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. 
% 
%------------------------------------------------------------------------------- 
Common; 
 
Subband_size = FFT_SIZE / 2 / N_SUBBAND;    % 8 
 
for n = 1:N_SUBBAND,  
   % 对每个子频带(For each subband), 共32个子频带 
    
   LTmin(n) = LTg(Map((n - 1) * Subband_size + 1)); 
    
   for j = 2:Subband_size, % Try all the samples in this subband 
      if (LTg(Map((n - 1) * Subband_size + j)) < LTmin(n)) 
         LTmin(n) = LTg(Map((n - 1) * Subband_size + j)); 
      end 
   end 
end