MATLAB: How to make updating music-scroller and timer-string while is playing music in matlab R2012

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Hi everyone. I wanna make it by using timer function. I dunno what I need to set up into 'timer' function as 'TimerFcn', 'StartTimerFcn' etc. And also the function 'drawnow' doesn't make any sence. Thanks for your responds.

Best Answer

https://www.mathworks.com/help/matlab/ref/audioplayer.html

audioplayer has a TimerFcn property, and a TimerPeriod property to set the interval. For example,

t = (0:size(y,1)-1)./Fs;
ax = gca;
plot(ax, t, y);
xlim([0 5]);
obj = audioplayer(y, Fs);
obj.TimerFcn = @(hObject, event) ScrollTo(ax, hObject.CurrentSample./hObject.SampleRate);
obj.TimerPeriod = 0.5;
play(obj)
function ScrollTo(ax, SampleTime)
   set(ax, 'XLim', SampleTime + [0 5]);
   drawnow()
end

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MATLAB: Push button audio for GUI

Change

play(player)

playblocking(player)

Otherwise the function will return after it starts playing, and when it returned it would destroy the local variables including the variable that stores the audio player; that would stop the playing.

MATLAB: Stopping a function in between GUI

Max - rather than using the sound function to play the audio recording, consider using an audio player object which provides the ability to stop the audio playback. For example, in your play button callback, you could do

% --- Executes on button press in pushbutton1.
function pushbutton1_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

fs = 44100; % Hz

t = 0:1/fs:10; % seconds
f = 440; % Hz
y = cos(2.*pi.*f.*t);
handles.hAudioPlayer = audioplayer(y,fs);
guidata(hObject, handles);
play(handles.hAudioPlayer);

The last three lines in the above code, we create the player, save the updated handles structure (which has a field for the handle to the audio player), and then start the (non-blocking) playback.

Now, in the stop button callback, you could do

% --- Executes on button press in pushbutton3.
function pushbutton3_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton3 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
if isfield(handles,'hAudioPlayer')
    stop(handles.hAudioPlayer);
end

We check to see if there exists an audio player handle field in the handles object, and if so, then we just stop the playback.

Try the above and see what happens!

Best Answer

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MATLAB: Push button audio for GUI

MATLAB: Stopping a function in between GUI

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