rmeddis@38: function outsignal = cutsignal(insignal,samplingfrequency,vocabularyset)
rmeddis@38: 
rmeddis@38: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
rmeddis@38: %
rmeddis@38: %   This function cuts the silence before and after the audiosignal
rmeddis@38: %
rmeddis@38: %  (c) Tim Jürgens, Medizinische Physik, Feb.2006
rmeddis@38: %
rmeddis@38: %  usage: outsignal = cutsignal(insignal,samplingfrequency,vocabularyset)
rmeddis@38: %
rmeddis@38: %   
rmeddis@38: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
rmeddis@38: 
rmeddis@38: % initial_energythreshold = 0.11;
rmeddis@38: % final_energythreshold = 0.05;
rmeddis@38: % 
rmeddis@38: % % choose initial and final delay due to different vocabularysets
rmeddis@38: % if (strcmp(vocabularyset,'f_f') > 0)
rmeddis@38: %     initial_delay = 0.17; % the speech started delay seconds before trespassing threshold (default 0.01, for f_f: 0.17)
rmeddis@38: %     final_delay = 0.2; %default 0.1, for f_f: 0.2
rmeddis@38: % else
rmeddis@38: %     initial_delay = 0.01; % the speech started delay seconds before trespassing threshold (default 0.01, for f_f: 0.2)
rmeddis@38: %     final_delay = 0.1; %default 0.1, for f_f: 0.2
rmeddis@38: % end
rmeddis@38: % 
rmeddis@38: % [initialsample_of_frame, energy] = compute_energy(insignal, samplingfrequency);
rmeddis@38: % for i = 1:length(initialsample_of_frame)
rmeddis@38: %     if (energy(i) > initial_energythreshold)
rmeddis@38: %         initialsample = initialsample_of_frame(i)-samplingfrequency*initial_delay;
rmeddis@38: %         break;
rmeddis@38: %     end
rmeddis@38: % end
rmeddis@38: % 
rmeddis@38: % time_inverted_energy = energy(end:-1:1); %turn signal around
rmeddis@38: % time_inverted_initialsample = initialsample_of_frame(end:-1:1);
rmeddis@38: % 
rmeddis@38: % for i = 1:length(time_inverted_initialsample)
rmeddis@38: %     if (time_inverted_energy(i) > final_energythreshold)
rmeddis@38: %         finalsample = time_inverted_initialsample(i)+samplingfrequency*final_delay;
rmeddis@38: %         break;
rmeddis@38: %     end
rmeddis@38: % end
rmeddis@38: % 
rmeddis@38: % if (finalsample > length(insignal))
rmeddis@38: %     finalsample = length(insignal);
rmeddis@38: % end
rmeddis@38: % outsignal = insignal(initialsample:finalsample);
rmeddis@38: 
rmeddis@38: if nargin < 3
rmeddis@38:     vocabularyset = 'a_a'; %default vocabularyset
rmeddis@38: end
rmeddis@38: 
rmeddis@38: 
rmeddis@38: 
rmeddis@38: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
rmeddis@38: initial_threshold = 0.15; %amplitude threshold for detection of speech
rmeddis@38: final_threshold = 0.1;
rmeddis@38: 
rmeddis@38: % choose initial and final delay due to different vocabularysets
rmeddis@38: if (strcmp(vocabularyset,'f_f') > 0)
rmeddis@38:     initial_delay = 0.2; % the speech started delay seconds before trespassing threshold (default 0.01, for f_f: 0.2)
rmeddis@38:     final_delay = 0.2; %default 0.1, for f_f: 0.2
rmeddis@38: else
rmeddis@38:     initial_delay = 0.01; % the speech started delay seconds before trespassing threshold (default 0.01, for f_f: 0.2)
rmeddis@38:     final_delay = 0.1; %default 0.1, for f_f: 0.2
rmeddis@38: end
rmeddis@38: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
rmeddis@38: 
rmeddis@38: 
rmeddis@38: %cut signal with taking initial delay into account
rmeddis@38: for(i = 1:length(insignal))
rmeddis@38:     if (abs(insignal(i)) > initial_threshold)
rmeddis@38:         initialsample = i - samplingfrequency*initial_delay;
rmeddis@38:         break;
rmeddis@38:     end
rmeddis@38: end
rmeddis@38: 
rmeddis@38: 
rmeddis@38: time_inverted_insignal = insignal(end:-1:1); %turn signal around
rmeddis@38: % cut it with taking a final delay into account
rmeddis@38: for(i = 1:length(time_inverted_insignal))
rmeddis@38:     if (abs(time_inverted_insignal(i)) > final_threshold)
rmeddis@38:         finalsample = i - samplingfrequency*final_delay;
rmeddis@38:         break;
rmeddis@38:     end
rmeddis@38: end
rmeddis@38: 
rmeddis@38: if (finalsample < 0)
rmeddis@38:     finalsample = 0;
rmeddis@38: end
rmeddis@38: if (initialsample < 1)
rmeddis@38:     initialsample = 1;
rmeddis@38: end
rmeddis@38: 
rmeddis@38: %% output %%%
rmeddis@38: outsignal = insignal(initialsample:end-finalsample);