Error using movie command in Matlab

I generated multiple images which I converted into frames with im2frame in order to create a movie. I used this code:

for i = 10:20
    images = sprintf('img%d.jpg',i); 
    ImageData = imread(images); 
    M(i) = im2frame(ImageData); 
end 
movie(M)
movie2avi(M,'sonar.avi','compression','None','fps',5,'quality',100)

When I run it, I get the following error:

Error using hgMovie
Movie contains uninitialized frames

Error in movie (line 41)
        builtin('hgMovie',varargin{:});

Error in open83B_edited_2 (line 324)
movie(M)

Does anyone have a clue what might be wrong with my code? Thank you!

Answer 1

[Geoff Hayes]

Hi Adrian,

I was able to reproduce the same issue with your above code. The problem is how the M array is being updated. The for loop iterates from 10 to 20 and the code uses these iteration values to assign the frame to the array. This means that M becomes an array of 20 frames, with the first nine not initialized - hence the error.

You can try the following instead:

% use this index into M
idxInM = 1;

for i = 10:20
    images = sprintf('img%d.jpg',i); 
    ImageData = imread(images); 
    M(idxInM) = im2frame(ImageData); 
    idxInM    = idxInM + 1;
end

Or any other mechanism that allows you to control how M is updated at each iteration.

[Adrian]

Thank you very much for your answer. In the end, I managed to solve it right away. You are right, yes. What I did is just write M(i-9) instead of M(i), and it worked. You can also skip out the index, and just write M, and still it would work.