MFCC特徵提取的結果矩陣是否具有負值？

Question

我正在使用MFCC提取功能來實現語音識別器我堅持使用HMM實現。我正在使用Kevin Murphy Toolbox for HMM。我的MFCC結果矩陣包含負值，這可能是我遇到的情況，我的MFCC代碼可能是錯誤的。以下是錯誤我getting-

Attempted to access obsmat(:,-39.5403); index must be a positive integer or logical. 

Error in multinomial_prob (line 19) 
    B(:,t) = obsmat(:, data(t)); 

Error in dhmm_em>compute_ess_dhmm (line 103) 
obslik = multinomial_prob(obs, obsmat); 

Error in dhmm_em (line 47) 
[loglik, exp_num_trans, exp_num_visits1, exp_num_emit] = ... 

Error in speechreco (line 77) 
[LL, prior2, transmat2, obsmat2] = dhmm_em(dtr{1}, prior, A, B, 'max_iter', 5); 

另外，如果有誰知道鏈接到任何Matlab的源代碼HMM請提供我堅持我的最後project.I想實現語音識別，不知道是什麼在提取特徵向量之後進行。

這是整個MATLAB代碼（我使用凱文·墨菲HMM工具包，誤差是在dhmm_em功能）：

function []=speechreco() 

vtr = {8}; fstr = {8}; nbtr = {8}; 
ctr = {8}; 

for i = 1:8 

    % Read audio data from train folder for performing operations 
    st=strcat('train\s',num2str(i),'.wav'); 
    [s1 , fs1 , nb1]=wavread(st); %st is filename; s1 is sample data, fs1 is frame rate in hertz, nb1 is number of bits per sample 
    vtr{i} = s1; fstr{i} = fs1; nbtr{i} = nb1; 

    ctr{i} = mfcc(vtr{i},fstr{i}); 

end 


display(ctr{1}); %MFCC matrix 20*129 

W1 = transpose(ctr{1}); 

ch1=menu('Mel Space:','Signal 1','Signal 2','Signal 3',... 
         'Signal 4','Signal 5','Signal 6','Signal 7','Signal 8','Exit'); 
        if ch1~=9 
         plot(linspace(0, (fstr{ch1}/2), 129), (melfb(20, 256, fstr{ch1}))); 
         title('Mel-Spaced-Filterbank'); 
         xlabel('Frequency[Hz]'); 
        end 


%error is here 
[LL, prior2, transmat2, obsmat2] = dhmm_em(ctr{1}, prior, A, B, 'max_iter', 5); 
plot(LL()); 

end 

%%mfcc 
%old one MFCC now 
function r = mfcc(s, fs) 
m = 100; 
n = 256; 
frame=blockFrames(s, fs, m, n); %power spectra obtained 
m = melfb(20, n, fs); 
n2 = 1 + floor(n/2); 
z = m * abs(frame(1:n2, :)).^2; %apply traingular window 
r = dct(log(z)); %take log and then the dct conversion 
end 



%% blockFrames Function 
% blockFrames: Puts the signal into frames 
% 
% Inputs: s contains the signal to analize 
% fs is the sampling rate of the signal 
% m is the distance between the beginnings of two frames 
% n is the number of samples per frame 
% 
% Output: M3 is a matrix containing all the frames 

function M3 = blockFrames(s, fs, m, n) 
l = length(s); 
nbFrame = floor((l - n)/m) + 1; 
for i = 1:n 
    for j = 1:nbFrame 
     M(i, j) = s(((j - 1) * m) + i); %#ok<AGROW> 
    end 
end 
h = hamming(n); 
M2 = diag(h) * M; 
for i = 1:nbFrame 
    M3(:, i) = fft(M2(:, i)); %#ok<AGROW> 
end 
end 
%-------------------------------------------------------------------------- 

function m = melfb(p, n, fs) %used for graph plot of power spectra 
% MELFB Determine matrix for a mel-spaced filterbank 
% 
% Inputs: p number of filters in filterbank 
% n length of fft 
% fs sample rate in Hz 
% 
% Outputs: x a (sparse) matrix containing the filterbank amplitudes 
% size(x) = [p, 1+floor(n/2)] 
% 
% Usage: For example, to compute the mel-scale spectrum of a 
% colum-vector signal s, with length n and sample rate fs: 
% 
% f = fft(s); 
% m = melfb(p, n, fs); 
% n2 = 1 + floor(n/2); 
% z = m * abs(f(1:n2)).^2; 
% 
% z would contain p samples of the desired mel-scale spectrum 
%%%%%%%%%%%%%%%%%% 
% 
f0 = 700/fs; 
fn2 = floor(n/2); 
lr = log(1 + 0.5/f0)/(p+1); 
% convert to fft bin numbers with 0 for DC term 
bl = n * (f0 * (exp([0 1 p p+1] * lr) - 1)); 
b1 = floor(bl(1)) + 1; 
b2 = ceil(bl(2)); 
b3 = floor(bl(3)); 
b4 = min(fn2, ceil(bl(4))) - 1; 
pf = log(1 + (b1:b4)/n/f0)/lr; 
fp = floor(pf); 
pm = pf - fp; 
r = [fp(b2:b4) 1+fp(1:b3)]; 
c = [b2:b4 1:b3] + 1; 
v = 2 * [1-pm(b2:b4) pm(1:b3)]; 
m = sparse(r, c, v, p, 1+fn2); 
end 
%---------------------------------------------------------------------- 

Answer 1

的錯誤不是關於MFCC負值，值可以是負的。錯誤指出索引是obsmat中的一個浮點值，這意味着您不正確地構造obsmat，它具有錯誤的類型，並且在錯誤的位置存在值和索引。您需要分享您編寫的全部代碼以顯示錯誤，而不僅僅是您調用HMM培訓的路線。

看你的代碼我看你可能需要用ctr調用dhmm_em，而不是用ctr {1}。