实时音频信号采集和处理系统.m

音频处理Matlab程序

function demoai_fft(varargin)

%%
% Error if an output argument is supplied.
if nargout > 0
   error('Too many output arguments.');
end

%%
% Based on the number of input arguments call the appropriate 
% local function.
switch nargin
case 0
   % Create the analog input object.
   data = localInitAI;

   % Create the  figure.
   data = localInitFig(data);
   hFig = data.handle.figure;
   
case 1
   error('The ADAPTORNAME, ID and CHANID must be specified.');
case 2
   % Initialize variables.
   data = [];
   action=varargin{1};
   hFig=varargin{2};
   
   try
      data=get(hFig,'UserData');
   catch e %#ok<NASGU>
       % This may fail if only the ADAPTORNAME and ID were input.  However,
       % if the ID was 0, this will work.
   end      
   
   % DATA will be empty if CHANID was not specified or if ID = 0.
   if isempty(data)
      error('The CHANID must be specified.');
   end
   
   % Based on the action, call the appropriate local function.
   switch action
   case 'close'
      localClose(data);
   case 'stop'
      data = localStop(data);
   end
case 3
      % User specified the input - adaptor, id, chanNum.
      % Create the analog input object.
      data = localInitAI(varargin{:});
      
      % Create the  figure.
      data = localInitFig(data);
      hFig = data.handle.figure;
end

%%
% Update the figure's UserData.
if ~isempty(hFig) && ishghandle(hFig),
   set(hFig,'UserData',data);
end

%%
% Update the analog input object's UserData.
if isvalid(data.ai)
   set(data.ai, 'UserData', data);
end

%% ***********************************************************************   
% Create the object and get the first fft.
function data = localInitAI(varargin)

% Initialize variables.
data = [];

%%
% Either no input arguments or all three - ADAPTORNAME, ID and CHANNELID.
switch nargin
case 0
   adaptor = 'winsound';%设置硬件设备对应名称
   id = 0;%应用声卡则无需设置硬件设备标识
   chan = 1;%选择左声道
case 3
   adaptor = varargin{1};
   id = varargin{2};
   chan = varargin{3};
otherwise
   error('daq:demoai_fft:invalidparam','The ADAPTORNAME, ID and CHANID must be specified.');
end

%%
% Error if more than one channel was specified.
if length(chan) > 1
   error('daq:demoai_fft:onechanonly','Only a single channel can be created.');
end

%%
% Channel 2 for sound card is not allowed.
if strcmpi(adaptor, 'winsound') && chan == 2
   warning('daq:demoai_fft:winsoundchan1','Channel 1 must be used for device Winsound.');
   chan = 1;
end

%%
% Object Configuration.
% Create an analog input object with one channel.
ai = analoginput(adaptor, id);%建立模拟输入对象ai
addchannel(ai, chan);%添加输入信号Chan到ai

%%
% Configure the analog input object.
set(ai, 'SampleRate', 44100);%设置采样频率

timePeriod = 0.1;

%%
% Configure the analog input object to trigger manually twice.
set(ai, 'SamplesPerTrigger', timePeriod*ai.sampleRate);
set(ai, 'TriggerRepeat', 1);
set(ai, 'TriggerType', 'manual');

%%
% Initialize callback parameters.  The TimerAction is initialized 
% after figure has been created.
set(ai, 'TimerPeriod', timePeriod);  
set(ai, 'BufferingConfig',[2048,20]);%每次采集后分配的空间为2048，共存储20次

%%
% Object Execution.
% Start the analog input object.
start(ai);%开始采样
trigger(ai);%启动触发

%%
% Obtain the available time and data.
[d,time] = getdata(ai, ai.SamplesPerTrigger);%数据和时间的二维表，获得采样值向量

%%
% Calculate the fft.
Fs = get(ai, 'SampleRate');%提取采样数据
blockSize = get(ai, 'SamplesPerTrigger');%设置数据块大小（采样点数）
[f,DAQfft,mag,phas] = localDaqfft(d,Fs,blockSize);%对输入信号进行FFT、幅值及相位运算
[d_filter,DAQfft_filter,mag_filter,phas_filter] = localDaqfft_filter1(d,Fs,blockSize);%对输入信号先进行巴特沃斯滤波，然后进行FFT、幅值及相位运算
%%
% Update the data structure.
data.ai = ai;
data.getdata = [d time];
data.daqfft =[f DAQfft];
data.daqfftmag = [f mag];
data.daqfftphas=[f phas];
data.getdata_filter = [d_filter time];
data.daqfft_filter =[f DAQfft_filter];
data.daqfftmag_filter = [f mag_filter];
data.daqfftphas_filter=[f phas_filter];
data.handle = [];

%%
% Set the object's UserData to data.
set(data.ai, 'UserData', data);

%% ***********************************************************************   
% 创建显示框体。
function data = localInitFig(data)

%%
% Initialize variables.
btnColor=get(0,'DefaultUIControlBackgroundColor');

%%
% 将GUI放置在屏幕中央。
screenUnits=get(0,'Units');
set(0,'Units','pixels');
screenSize=get(0,'ScreenSize');
set(0,'Units',screenUnits);
figWidth=600;
figHeight=360;
 figPos=[(screenSize(3)-figWidth)/2 (screenSize(4)-figHeight)/2  ...
       figWidth                    figHeight];

%%
% 创建图形窗口。
hFig=figure(...                    
   'Color'             ,btnColor                 ,...
   'IntegerHandle'     ,'off'                    ,...
   'DoubleBuffer'      ,'on'                     ,...
   'DeleteFcn'         ,'demoai_fft(''close'',gcbf)',...
   'MenuBar'           ,'none'                   ,...
   'HandleVisibility'  ,'on'                     ,...
   'Name'              ,'数据采集系统'  ,...
   'Tag'               ,'Analog Input FFT demo'  ,...
   'NumberTitle'       ,'off'                    ,...
   'Units'             ,'pixels'                 ,...
   'Position'          ,figPos                   ,...
   'UserData'          ,[]                       ,...
   'Colormap'          ,[]                       ,...
   'Pointer'           ,'arrow'                  ,...
   'Visible'           ,'off'                     ...
   );

%%
% 绘制滤波前信号波形。
hAxes(1) = axes(...%调用设置好的hAxes(1)句柄，根据参数对图像的两个轴进行绘制（210,566行）
   'Position'          , [0.05 0.6 0.19 0.3],...
   'Parent'            , hFig,...
   'XLim'              , [0 get(data.ai, 'SamplesPerTrigger')],...
   'YLim'              , [-0.5 0.5]...
   );
hLine(1) = plot(data.getdata(:,1));%调用设置好的hLine(1)句柄，利用Plot函数对采样的图像进行实时绘制
set(hAxes(1), 'XLim', [0 get(data.ai, 'SamplesPerTrigger')]);%设置hAxes（1）句柄的属性，运用采样点数对X轴进行控制
xlabel('采样点');
ylabel('模拟输入 (V)');
title('滤波前的信号波形');

%%
% 绘制滤波前信号频谱。
hAxes(2) = axes(...
   'Position'          , [0.29 0.6 0.19 0.3],...
   'Parent'            , hFig,...
   'XLim'              , [0 max(data.daqfft(:,1))]...
   );
hLine(2) = plot(data.daqfft(:,1),data.daqfft(:,2));
set(hAxes(2), 'XLim', [0 5000]);
xlabel('频率 (Hz)');
ylabel('');
title('滤波前信号频谱');

%%
% 绘制滤波前信号幅度谱。
hAxes(3) = axes(...
   'Position'          , [0.54 0.6 0.19 0.3],...
   'Parent'            , hFig,...
   'XLim'              , [0 max(data.daqfftmag(:,1))]...
   );
hLine(3) = plot(data.daqfftmag(:,1),data.daqfftmag(:,2));
set(hAxes(3), 'XLim', [0 max(data.daqfftmag(:,1))]);
xlabel('频率（Hz)');
ylabel('幅值（dB)');
title('滤波前信号对数幅频特性');

%%
% 绘制滤波前信号相位谱。
hAxes(4) = axes(...
   'Position'          , [0.79 0.6 0.19 0.3],...
   'Parent'            , hFig,...
   'XLim'              , [0 max(data.daqfftphas(:,1))]...
   );
hLine(4) = plot(data.daqfftphas(:,1),data.daqfftphas(:,2));
set(hAxes(4), 'XLim', [0 max(data.daqfftphas(:,1))]);
xlabel('频率 (Hz)');
ylabel('相位角(角度)');
title('滤波前信号相位谱');

%%
% 绘制滤波后信号波形。
hAxes(5) = axes(...
   'Position'          , [0.05 0.15 0.19 0.3],...
   'Parent'            , hFig,...
   'XLim'              , [0 get(data.ai, 'SamplesPerTrigger')],...
   'YLim'              , [-0.5 0.5]...
   );
hLine(5) = plot(data.getdata_filter(:,1));
set(hAxes(5), 'XLim', [0 get(data.ai, 'SamplesPerTrigger')]);
xlabel('采样点');
ylabel('模拟输入 (V)');
title('滤波后的信号波形');

%%
% 绘制滤波后信号频谱。
hAxes(6) = axes(...
   'Position'          , [0.29 0.15 0.19 0.3],...
   'Parent'            , hFig,...
   'XLim'              , [0 max(data.daqfft_filter(:,1))]...
   );
hLine(6) = plot(data.daqfft_filter(:,1),data.daqfft_filter(:,2));
set(hAxes(6), 'XLim', [0 5000]);
xlabel('频率 (Hz)');
ylabel('');
title('滤波后信号频谱');

%%
% 绘制滤波后信号幅度谱。
hAxes(7) = axes(...
   'Position'          , [0.54 0.15 0.19 0.3],...
   'Parent'            , hFig,...
   'XLim'              , [0 max(data.daqfftmag_filter(:,1))]...
   );
hLine(7) = plot(data.daqfftmag_filter(:,1),data.daqfftmag_filter(:,2));
set(hAxes(7), 'XLim', [0 max(data.daqfftmag_filter(:,1))]);
xlabel('频率（Hz)');
ylabel('幅值（dB)');
title('滤波后信号对数幅频特性');

%%
% 绘制滤波后信号相位谱。
hAxes(8) = axes(...
   'Position'          , [0.79 0.15 0.19 0.3],...
   'Parent'            , hFig,...
   'XLim'              , [0 max(data.daqfftphas_filter(:,1))]...
   );
hLine(8) = plot(data.daqfftphas_filter(:,1),data.daqfftphas_filter(:,2));
set(hAxes(8), 'XLim', [0 max(data.daqfftphas_filter(:,1))]);
xlabel('频率 (Hz)');
ylabel('相位角(角度)');
title('滤波后信号相位谱');

%%
% 创建一个开始/暂停按钮。
htoggle = uicontrol(...