how to divide the .wmv (movie) format to multiple images?

sir, Now i need to know how to make the .wmv movie to the multiple frames of the images. here i use the mmreader function to find the frames but it shows the error the

 warning: Unable to determine the number of frames in this file.

1. how to find the number of frames in the .wmv

2. Next how to make the movie to the multiple images

Answer 1

[Walter Roberson]

The movie is a variable-time movie. You need to read in the entire movie once before mmreader knows the number of frames in the movie.

You use mmreader to read one frame at a time, and imwrite() the cdata of the frame to a file.

[ajith]

how to use imwrite , are you specified using imwrite to save each frame can you explain the answer in the coding sir

[Walter Roberson]

imwrite(YourDataMatrix, 'YourFileName.tif');

[ajith]

readerobj = mmreader('dec072012132350.wmv');

frame = read(readerobj,inf);

readerobj.NumberOfFrames

Warning: Unable to determine the number of frames in this file.

ans =

   498
now I found the number of frames and how to save all the frames of the video into the image

[Walter Roberson]

readerobj = mmreader('dec072012132350.wmv');

fidx = 1;
while true
  try ME
    frame = read(readerobj, fidx);
  catch
    break;
  end
  imgname = sprintf('frame%05d.tif', fidx);
  imwrite(frame, imgname);
  fidx = fidx + 1;
end

[ajith]

I run your following script its shows the warning

readerobj = mmreader('dec072012132350.wmv');

fidx = 1;

while true

try ME

    frame = read(readerobj, fidx);
  catch
    break;
  end
  imgname = sprintf('frame%05d.tif', fidx);
  imwrite(frame, imgname);
  fidx = fidx + 1;
end
Warning: Unable to determine the number of frames in this
file. 
Warning: This try-catch syntax will continue to work in R2007b,
 but may be illegal or may mean something different in future releases of MATLAB.
 See Release Notes for MATLAB Version 7.4, "Warning Generated by try-catch" for details.

Now what to do sir

[Walter Roberson]

They are only warnings.

To get rid of the second one, change

try ME

to

try

and change

catch

to

catch ME

[ajith]

only shows the

ans =

    3

[Walter Roberson]

I am not expecting it to show even that. The imwrite() take place silently. But if you like, before the "fidx = fidx + 1" line, add

fprintf('wrote frame to %s\n', imgname);

[ajith]

sir i get the total number of frame at 498 by using this code

readerobj = mmreader('dec072012132350.wmv');

frame = read(readerobj,inf);

readerobj.NumberOfFrames

Warning: Unable to determine the number of frames in this file.

ans =

     498
  now I found the number of frames
  end

but i save the code in editor window to run it shows the ans=1 but in the command window i run separately each codes line by line it shows the ans = 498 how its possible

and also i run your script

readerobj = mmreader('dec072012132350.wmv');
fidx = 1;
while true
  try 
    frame = read(readerobj, fidx);
  catch ME
    break;
  end
  imgname = sprintf('frame%05d.tif', fidx);
  imwrite(frame, imgname);
  fprintf('wrote frame to %s\n', imgname);
  fidx = fidx + 1;
end

in the command window its show the more than 498 frames been saved and also run accords through the editor window show ans = 3 but separately in command window its gives the result of saved images more than 498 frames . i didn't have deep knowledge in the mmreader concept so clearly explain as soon as possible sir

[Walter Roberson]

Any "ans =" you get from my script should be ignored, as the script makes no calculations that are intended to be output.

For your script try

readerobj = mmreader('dec072012132350.wmv');
frame = read(readerobj,inf);
numframe = readerobj.NumberOfFrames;
numframe

[ajith]

sir i found the mistake i did i save the file name as 1.m so the ans= 1, and the file name 2.m so the ans = 2 thank you for your kind help

[Walter Roberson]

Yes, that would do it. You cannot name a .m file with a number -- or rather, if you do, the number will be output instead of running the file.