excitation_create.m

来自「这是一个用于语音信号处理的工具箱」· M 代码 · 共 108 行

%Callback function for the Create new file button in the new file window
%
%Author : Albert Hsiao
%Karthik 2/97 ...used Albert's code to create this program
%A filename can be specified interactively.
%The source file is named filename_source and the formant file is
%called filename_formant.
%Modified greatly by D. G. Childers 2/25/98 to eliminate the time varying features

clear excitation;

segment_no=1;
%Nframe = 20;%Default number of frames
if exist ('Nframe1')
   Nframe=Nframe1;
end
Srate = 10000;     %Default sampling rate

%% generate a default source file %%


Pitch=100*ones(Nframe,1);  % pitch period
Vgain= 5*ones(Nframe,1);    % voicing gain
Lcof= ones(Nframe,5);      % 5 LF timing coefficients
Lcof(:,1)=50*Lcof(:,1);   % Ee
Lcof(:,2)=0.5*Lcof(:,2);  % Tp
Lcof(:,3)=0.6*Lcof(:,3);  % Te
Lcof(:,4)=0.05*Lcof(:,4); % Ta
Lcof(:,5)=0.8*Lcof(:,5);  % Tc

Ngain=zeros(Nframe,1);    % fricative noise gain
Ncof=ones(Nframe,5);      % 5 noise coefficients
Ncof(:,1)=0*Ncof(:,1);    % asp. noise gain
Ncof(:,2)=0*Ncof(:,2);    % amp1
Ncof(:,3)=0.75*Ncof(:,3); % offset
Ncof(:,4)=0*Ncof(:,4);    % amp2
Ncof(:,5)=0.25*Ncof(:,5); % duration

%Generate the default excitation signal

%Voiced excitation
% 1. calculate the LF model waveform for voiced excitation
Tp=Lcof(1,2);
Te=Lcof(1,3);
Ta=Lcof(1,4);
Tc=Lcof(1,5);
Ee=Lcof(1,1);
Lens=Pitch(1);
temp_excitation = lfpuls(Tp,Te,Ta,Tc,Ee,Lens);
gm=Vgain(1)-Ngain(1)-Ncof(1,1);
if Vgain(1)==0
   amp=0;
else
   amp=sqrt(gm*Lens/sum(temp_excitation.^2));
end
temp_excitation = amp*temp_excitation;

% 2. calculate the noise exciation 
Aspgain=Ncof(1,1);  % aspiration noise gain
Amp1=Ncof(1,2);
Offset=Ncof(1,3);
Amp2=Ncof(1,4);
Duration=Ncof(1,5);
Fgain=Ngain(1);  % fricative noise gain

temp_noise_excitation=nspuls(Amp1,Offset,Amp2,Duration,Lens,Aspgain,Fgain);

% 3. plot the combined the excitation waveform (voiced+unvoiced)

temp_excitation = temp_excitation + temp_noise_excitation;

%Replicate this array to produce the excitation 
for i = 1:Nframe
   start_point = (i*Lens) - (Lens-1);
   end_point = start_point + Lens - 1;
   excitation(start_point:end_point) = temp_excitation;
end
Lens_array = Pitch;
uvindicate = ones(1,Nframe);


PV = [436 204 244 81];
s2 = 'Excitation has been created';
message_fig = figure('Position',PV,...
   'Numbertitle','off',...
   'Color',[0.5 0.5 0.5],...
   'Name',s2);

uicontrol('Style','Frame',...
   'Units','Normalized',...
   'Position',[0.05 0.05 0.9 0.9],...
   'BackGroundColor',[0.9 0.9 0.9]);

uicontrol('Style','text',...
   'Units','Normalized',...
   'Position',[0.1 0.2 0.8 0.4],...
   'ForegroundColor','red',...
   'BackGroundColor',[0.9 0.9 0.9],...
   'String','A default source has been created. You can modify it now');


pause(3);

close(message_fig);
clear message_fig;