Problem with mmreader and capture frame

Alric Gta — Thu, 04 Jun 2009 10:57:00 -0400

Hi,

I read a movie with the function mmreader and I tried to extract a specific frame from my video.I have extracted the frame but has lots of horizontal lines and I can see anything. ==== Why ???

I need to do this in Matlab

I mean I want to run the movie in matlab WM player and when I hit the pause button to extract the frame that I see on my player.

To know wich one need to be extracted I use a counter.

Here is my code:

It make some lines on my images and I can see anything

see the link below:

http://i361.photobucket.com/albums/oo54/Rikom/frame58.png

My GUI see link below:

http://i361.photobucket.com/albums/oo54/Rikom/MyGui2.png

==============

I want to run the video in matlab WMPlayer( it is working no problem in here) and
when I push the pause button I want to extract the current Frame (I have done a counter to count my frames, to know wich one to extract)

Problems need to be solved :

1. Why when I use
poza=read(handles.film,58) % extract frame 58 it makes the img with lines on it see first link
2. When I use

frame=get(handles.counter,'string'); % frame = 58 or the value when I push the pause button
poza=read(handles.film,frame);

==================================================
it gives me this err:

??? Error using ==> mmreader.read at 81
INDEX must be a numeric scalar or 1x2 vector.

Error in ==> myvid>pause_Callback at 160
poza=read(handles.film,frame);

Error in ==> gui_mainfcn at 96
        feval(varargin{:});

Error in ==> myvid at 42
    gui_mainfcn(gui_State, varargin{:});

Error in ==> @(hObject,eventdata)myvid('pause_Callback',hObject,eventdata,guidata(hObject))

??? Error using ==> pause
Error while evaluating uicontrol Callback
===================================================

My code :

function myvid_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject handle to figure
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
% varargin command line arguments to myvid (see VARARGIN)

% Choose default command line output for myvid
handles.output = hObject;

set(gcf,'Color',[0.7 0.7 0.7]); % gcf=get current figure handle si seteaza culoarea asa1=[0 0 0] si asa2=[0.7 0.7 0.7]
pos=[10 100 800 800]; % pos player
% m=figure;
MovieControl = actxcontrol('WMPlayer.OCX.7',pos)
% set(MovieControl,'uiMode','none'); % ca sa dispara bara de optiuni de jos player-ului
assignin('base','MovieControl',MovieControl);
get(MovieControl)
set(MovieControl.settings,'autoStart',0);
handles.film=mmreader('y.avi');

%================================================

function open_Callback(hObject, eventdata, handles)
% hObject handle to open (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)

[filename pathname] = uigetfile('*.*','Please select a file')

if ~filename
    return
end;

file1=[pathname filename]
[path,name,ext,ver] = fileparts(file1);

mp= evalin('base', 'MovieControl');
mp.URL=[pathname filename];

handles.film=mmreader(mp.URL)
% poza=frame2im(handles.film(30));
% figure,imshow(poza);

guidata(hObject, handles)
%===============================================

function start_Callback(hObject, eventdata, handles)
% hObject handle to start (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
set(handles.start,'UserData',1);
mp= evalin('base', 'MovieControl')
mp.controls.play
while (get(handles.start,'UserData') ==1)
    %increments the counter
    temp = str2num(get(handles.counter,'String'));
    temp = temp + 1;
    set(handles.counter,'String',num2str(temp));
pause(0.040);
    %"flushes the event queue" and updates the figure window
    %since Matlab is a single thread process, this command is requierd
    drawnow
end

guidata(hObject, handles);

%=========================================

function pause_Callback(hObject, eventdata, handles)
% hObject handle to pause (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)

mp= evalin('base', 'MovieControl')
mp.controls.pause
set(handles.start,'UserData',0);
frame=get(handles.counter,'String')

% vidFrame = getframe(gcf);
% poza=frame2im(vidFrame);
poza=read(handles.film,58);
figure,imshow(poza);
%================================================

Thanks and hope somebody can help me

Re: Problem with mmreader and capture frame

Leslie McBrayer — Thu, 04 Jun 2009 13:18:21 -0400

> I read a movie with the function mmreader and I tried to extract a
> specific frame from my video.I have extracted the frame but has lots of
> horizontal lines and I can see anything. ==== Why ???

This may be related to a known bug in mmreader, which has a workaround.
See:

http://www.mathworks.com/support/bugreports

and search for mmreader and/or 536560.

> 2. When I use
>
> frame=get(handles.counter,'string'); % frame = 58 or the value when I push
> the pause button
> poza=read(handles.film,frame);
>
> ==================================================
> it gives me this err:
>
> ??? Error using ==> mmreader.read at 81
> INDEX must be a numeric scalar or 1x2 vector.
>

Try changing

> frame=get(handles.counter,'String')

to

frame = str2num(get(handles.counter,'String'))

Re: Problem with mmreader and capture frame

Alric Gta — Thu, 04 Jun 2009 15:55:03 -0400

Thanks for the help is working with:

frame = str2num(get(handles.counter,'String'))

but what about those horizontal lines (see the picture at the link that I have posted)

Why does extract the frame like that and how can I fix this really need the image to be seen perfect.

What other function(like read) I could use to extract a specific frame from my video.

Just a little help.

Re: Problem with mmreader and capture frame

Leslie McBrayer — Thu, 04 Jun 2009 16:03:09 -0400

"Alric Gta" <alric2rei@yahoo.com> wrote in message
news:h08qon$c09$1@fred.mathworks.com...
>
> Thanks for the help is working with:
>
> frame = str2num(get(handles.counter,'String'))
>
> but what about those horizontal lines (see the picture at the link that I
> have posted)
>
> Why does extract the frame like that and how can I fix this really need
> the image to be seen perfect.
>
> What other function(like read) I could use to extract a specific frame
> from my video.
>
> Just a little help.

Assuming you're on a Windows system, try the workaround for bug ID #536560
here:

http://www.mathworks.com/support/bugreports/search_results?search_executed=1&keyword=mmreader&release_filter=Exists+in&release=160&selected_products=

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