tof.m

matlab开发的一个声音处理程序

function varargout = tof(varargin)
% TOF demonstrates sound ranging (sonar) between PC
%   speaker and microphone (up to 6m away).
%
% This demo requires:
%   - Data Acquisition Toolbox,
%   - Signal Processing Toolbox
%   - Windows sound card
%   - files: sonar_anal.m tof.fig tof.m (this file)
%
% How does it work?
%   A pulse wave (chirp) is generated from the speaker,
%   which travels through air at the speed of sound.  
%   At the same time the microphone records the received
%   wave (plus possible reflections depending on room
%   acoustics).  The propagation time delay (sec) is 
%   measured and converted to distance (m).

% (c) 2001 R.A.Bemis, The MathWorks, Inc.

% TOF Application M-file for tof.fig
%    FIG = TOF launch tof GUI.
%    TOF('callback_name', ...) invoke the named callback.

% Last Modified by GUIDE v2.0 18-Oct-2001 17:27:18

if nargin == 0  % LAUNCH GUI

	fig = openfig(mfilename,'reuse');

	% Use system color scheme for figure:
	set(fig,'Color',get(0,'defaultUicontrolBackgroundColor'));

	% Generate a structure of handles to pass to callbacks, and store it. 
	handles = guihandles(fig);
	guidata(fig, handles);

    sonar_setup(handles,0.0087)  % set up audio I/O
    
	if nargout > 0
		varargout{1} = fig;
	end

elseif ischar(varargin{1}) % INVOKE NAMED SUBFUNCTION OR CALLBACK

	try
		if (nargout)
			[varargout{1:nargout}] = feval(varargin{:}); % FEVAL switchyard
		else
			feval(varargin{:}); % FEVAL switchyard
		end
	catch
		disp(lasterr);
	end

end


%| ABOUT CALLBACKS:
%| GUIDE automatically appends subfunction prototypes to this file, and 
%| sets objects' callback properties to call them through the FEVAL 
%| switchyard above. This comment describes that mechanism.
%|
%| Each callback subfunction declaration has the following form:
%| <SUBFUNCTION_NAME>(H, EVENTDATA, HANDLES, VARARGIN)
%|
%| The subfunction name is composed using the object's Tag and the 
%| callback type separated by '_', e.g. 'slider2_Callback',
%| 'figure1_CloseRequestFcn', 'axis1_ButtondownFcn'.
%|
%| H is the callback object's handle (obtained using GCBO).
%|
%| EVENTDATA is empty, but reserved for future use.
%|
%| HANDLES is a structure containing handles of components in GUI using
%| tags as fieldnames, e.g. handles.figure1, handles.slider2. This
%| structure is created at GUI startup using GUIHANDLES and stored in
%| the figure's application data using GUIDATA. A copy of the structure
%| is passed to each callback.  You can store additional information in
%| this structure at GUI startup, and you can change the structure
%| during callbacks.  Call guidata(h, handles) after changing your
%| copy to replace the stored original so that subsequent callbacks see
%| the updates. Type "help guihandles" and "help guidata" for more
%| information.
%|
%| VARARGIN contains any extra arguments you have passed to the
%| callback. Specify the extra arguments by editing the callback
%| property in the inspector. By default, GUIDE sets the property to:
%| <MFILENAME>('<SUBFUNCTION_NAME>', gcbo, [], guidata(gcbo))
%| Add any extra arguments after the last argument, before the final
%| closing parenthesis.



% --------------------------------------------------------------------
function varargout = Single_Callback(h, eventdata, handles, varargin)

set(handles.Repeat,'enable','off')      % disable Repeat button
sonar_once(handles.figure1)             % take one measurement



% --------------------------------------------------------------------
function varargout = Repeat_Callback(h, eventdata, handles, varargin)

set(h,'enable','off')                   % disable Repeat button
set(handles.Single,'enable','off')      % disbale Single button
set(handles.Stop,'enable','on')         % enable Stop button
sonar_run(handles.figure1)              % measure repeatedly



% --------------------------------------------------------------------
function varargout = Stop_Callback(h, eventdata, handles, varargin)

set(h,'enable','off')                   % disable Stop button
set(handles.Repeat,'enable','on')       % enable Repeat button
set(handles.Single,'enable','on')       % enable Single button
sonar_stop(handles.figure1)             % stop repeats



% --------------------------------------------------------------------
function sonar_setup(handles,cal_lag)

fig=handles.figure1;            % figure handle

if nargin<2, cal_lag=0; end

% physics
c=330;                          % speed of sound (m/sec)
d=50;                           % max distance (m)
Td=d/c;                         % max return time (sec)
pw=0.01;                        % pulse width (sec)
Tmax=Td+pw;                     % total response time (sec)

% DAQ parameters
ai=analoginput('winsound');             % create AI object
addchannel(ai,1);                       % single channel (mono)
Fs=setverify(ai,'samplerate',44100);    % sample rate (Hz)
N=2^ceil(log2(Tmax*Fs));                % buffer size (samples)
ao=analogoutput('winsound');            % create AO object
addchannel(ao,1);                       % single channel (mono)
ao.SampleRate=Fs;                       % output Fs same as input

% excitation chirp
f0=8e3; f1=12e3;                        % freq range (Hz)
t=[0:(1/Fs):pw]';                       % time index (sec)
n=length(t);                            % pulse length (samples)
pulse=chirp(t,f0,pw,f1);                % chrip waveform (short)
pulse=pulse.*hanning(n);                % pulse envelope
pad=zeros(N-n,1);                       % silence trailing chirp
x=[pulse; pad];                         % excitation (zero padded)

% response waveform
ai.SamplesPerTrigger=N;                 % total samples to acquire
ai.TriggerDelayUnits='sec';             % trigger delay=0 sec
ai.TriggerDelay=cal_lag;                % calibration lag factor (sec)
ai.SamplesAcquiredFcnCount=N;
ai.SamplesAcquiredFcn=['sonar_anal(' num2str(fig) ')'];

% user data
ud.ai=ai;                   % audio input
ud.ao=ao;                   % audio output
ud.c=c;                     % wave speed in air
ud.x=x;                     % excitation waveform
ud.h=handles;               % guide figure handles
set(fig,'userdata',ud)      % store bundle with figure



% --------------------------------------------------------------------
function sonar_once(fig)

% user data
ud=get(fig,'userdata');     % user data fields
ai=ud.ai;                   % audio input
ao=ud.ao;                   % audio output
x=ud.x;                     % excitation chirp pulse
ai.samplesacquiredfcn='';   % don't repeat measurement
putdata(ao,x)               % arm audio output
start([ai ao])              % start measurement
sonar_anal(fig)             % manually analyze data



% --------------------------------------------------------------------
function sonar_run(fig)

% user data
ud=get(fig,'userdata');     % user data fields
ai=ud.ai;                   % audio input
ao=ud.ao;                   % audio output
x=ud.x;                     % excitation chirp pulse

% callback function to analyze when done acquiring data
ai.samplesacquiredfcn=['sonar_anal(' num2str(fig) ')'];
% NOTE: sonar_anal will rearm output and repeat measurement

putdata(ao,x)               % arm audio output
start([ai ao])              % start measuring (will repeat)



% --------------------------------------------------------------------
function sonar_stop(fig)

% user data
ud=get(fig,'userdata');     % user data fields
ai=ud.ai;                   % audio input
ai.samplesacquiredfcn='';   % stop repeating



% --------------------------------------------------------------------
function sonar_cleanup(fig)

% user data
ud=get(fig,'userdata');     % user data fields
ai=ud.ai; delete(ai)        % remove audio input
ao=ud.ao; delete(ao)        % remove audio output



% --------------------------------------------------------------------
function varargout = figure1_CloseRequestFcn(h, eventdata, handles, varargin)

sonar_stop(handles.figure1)         % stops if still repeating
sonar_cleanup(handles.figure1)      % remove audio objects
delete(handles.figure1)             % remove figure window