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

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.

[Walter Roberson]

Which sound player are you using? Some of them have built-in timer properties.

[Temirkhan Amanzhanov]

I use an 'audioplayer(fs,y)'.

Answer 1

[Walter Roberson]

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

[Temirkhan Amanzhanov]

Thanks for respond, sir Roberson. I wanna show what I set up into play button. Is that correct? Cause I've got some errors in slider callback. The 1st function is playbutton callback for player and the 2nd function is a slider callback. And also, I use listbox to create kinda 'Playlist' for an 'Audioplayer'. This listbox' name is 'listaudiofiles_Callback' and it is below. Thanks

function playbutton_Callback(hObject, eventdata, handles)

global app nSam nStore nMin nSec tf player ax
app = guidata(handles.figure1);

nSample = get(player, 'CurrentSample'); 
                 
nSam = nSample/app.freqSam;
nMin = floor(nSam / 60);
nSec = round(mod(nSam, 60));  
    
hms = sprintf('%02d:%02d', nMin, nSec);
set(handles.timer1,'String',hms)
   
nSam = nStore + 1;
tf = strcmp(hms,'00:00');


if (tf == 1)   
    nSam = nStore;    
    pause(player)
else if (tf == 1)         
        nSam = nStore;         
        pause(player);        
    end
end


if (app.flag == 2) 
    t = imread('pausebutton.png');
    ImRes = imresize(t, 0.34);
    set(handles.playbutton, 'CData', ImRes);
    app.flag = 1;  
    
    player = audioplayer(app.dataLenght, app.freqSam);
    player.TimerFcn = @(hObject, event) ScrollTo(ax, hObject.CurrentSample./hObject.SampleRate);
    player.TimerPeriod = 0.5;
    
    t = (0:size(app.dataLenght,1)-1)./app.freqSam;
    ax = gca;
    plot(ax, t, app.dataLenght);
    xlim([0 5]);       
    play(player);    
    while (isplaying(player) == true)
        CurrSam = get(player, 'CurrentSample');
        set(handles.audioslider, 'Value', CurrSam);
        drawnow()
    end
else
    if(app.flag == 1)
        t = imread('playbutton.png');
        ImRes = imresize(t, 0.34);
        set(handles.playbutton, 'CData',ImRes);        
        app.flag = 0;
        pause(player);         
        
    else
        t = imread('pausebutton.png');
        ImRes = imresize(t, 0.34);
        set(handles.playbutton, 'CData',ImRes);        
        app.flag = 1;
        resume(player);        
        
    end
end
guidata(handles.figure1, app);

function ScrollTo(ax, SampleTime)
set(ax, 'XLim', SampleTime + [0 5]);
drawnow()
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


function audioslider_Callback(hObject, eventdata, handles)

global pos nSam tf pstore pmins psecs player;
pos = get(hObject,'Value');

pos = uint16(pos);
pos = double(pos);
pstore = pos;
phours = floor(pstore / 3600);
pstore = pstore - phours * 3600;
pmins = floor(pstore / 60);
psecs = pstore - pmins * 60;
phms = sprintf('%02d:%02d', pmins, psecs);
set(handles.timer1,'String',phms)

xPlayer = get(player, 'SampleRate');
skip = xPlayer * pos;

if (pos == nSam)
    t = imread('playbutton.png');
    ImRes = imresize(t, 0.34);
    set(handles.playbutton, 'CData',ImRes);
    
    nSam = nSam + pos;
    pause(player)  
    
    
else
    if (tf == 0)
        
        t = imread('pausebutton.png');
        ImRes = imresize(t, 0.34);
        set(handles.playbutton, 'CData',ImRes);
        
        nSam = nSam + pos;
        stop(player)
        play(player, skip)
         
        
    else
        t = imread('pausebutton.png');
        ImRes = imresize(t, 0.34);
        set(handles.playbutton, 'CData',ImRes);
        
        nSam = nSam + pos;
        stop(player)
        play(player, skip)
                
    end
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

function listaudiofiles_Callback(hObject, eventdata, handles)

global app nSam nMin nSec nStore player;
app = guidata(handles.figure1);

app.listStr = get(hObject, 'String');
app.listVal = get(hObject, 'Value');

if (iscell(app.listStr)) 
    app.fileName = app.listStr{app.listVal}; 
    set(handles.audiotitle, 'String', app.fileName);   
    
    t = imread('playbutton.png');
    ImRes = imresize(t, 0.34);
    set(handles.playbutton, 'CData', ImRes);   
    
    [y, fs] = audioread(app.fileName);    
    app.freqSam = fs;
    app.dataLenght = y;
    
    nSample = size(app.dataLenght, 1);     
    nSam = nSample/app.freqSam;
    nMin = floor(nSam/60);
    nSec = round(mod(nSam, 60)); 
    
    nSam = uint16(nSam);
    nSam = double(nSam);
    nStore = nSam;
    
    player = audioplayer(app.dataLenght, app.freqSam);
    app.flag = 2;     
     
    set(handles.audioslider,'Max', nStore);
    set(handles.audioslider,'Min',0);   
        
    hms = sprintf('%02d:%02d', nMin, nSec);
    set(handles.timer2,'String',hms)    
    strcmp(hms,'00:00');        
    
    
else 
    app.fileName = app.listStr;
    set(handles.audiotitle, 'String', app.fileName);  
    
    t = imread('playbutton.png');
    ImRes = imresize(t, 0.34);
    set(handles.playbutton, 'CData', ImRes);
    [y, fs] = audioread(app.fileName);
    
    app.freqSam = fs;
    app.dataLenght = y;
    
    nSample = size(app.dataLenght, 1);     
    nSam = nSample/app.freqSam;
    nMin = floor(nSam/60);
    nSec = round(mod(nSam, 60)); 
    
    nSam = uint16(nSam);
    nSam = double(nSam);
    nStore = nSam;
    
    player = audioplayer(app.dataLenght, app.freqSam);
    app.flag = 2;     
     
    set(handles.audioslider,'Max', nStore);
    set(handles.audioslider,'Min',0);   
        
    hms = sprintf('%02d:%02d', nMin, nSec);
    set(handles.timer2,'String',hms)    
    strcmp(hms,'00:00'); 
    
    
end
guidata(handles.figure1, app);

[Walter Roberson]

That code is a mix of using App Designer and GUIDE, and it would be a bunch of trouble to fix it up.

If you had a GUIDE gui that you want to use with App Designer then there is a migration tool.

[Walter Roberson]

Oh, wait, you are using a release that is way too old for App Designer.

However did your code get into that state ???

[Temirkhan Amanzhanov]

Yes, I have an old version of Matlab (at least R2012b) and I use GUIDE, so I had some problems finding any solution for the "handles" in my audioplayer project. And yeah, I'm doing this project for my school (I don't know why it's the R2012b version...). I would say it's kind of a mix of solutions that I can find all over the Internet :) And there are some issues with the listbox as well. I will be happy if you can help me to solve it.

[Walter Roberson]

Using global variables and using "app" is not recommended for GUIDE. "app" is for App Designer.

See

http://matlab.wikia.com/wiki/FAQ#How_can_I_share_data_between_callback_functions_in_my_GUI.28s.29.3F

Also I suggest

    player.TimerFcn = @(hObject, event) ScrollTo(ax, hObject)

with

function ScrollTo(ax, hObject)
  handles = guidata(ax);
  SampleTime = hObject.CurrentSample./hObject.SampleRate;
  set(ax, 'XLim', SampleTime + [0 5]);
  handles.audioslider.Value = SampleTime;
  drawnow()

and remove the lines

    while (isplaying(player) == true)
        CurrSam = get(player, 'CurrentSample');
        set(handles.audioslider, 'Value', CurrSam);
        drawnow()
    end

as those are better done by the ScrollTo

Ah, though you should decide whether you want the audioslider to be by sample number or by seconds.

[Temirkhan Amanzhanov]

Thanks a lot, sir Roberson :) I can finally set it up correctly.