How to use images from a video?

Can any one help me with coding of a 2d DCT(4x) for a video? please

• *Method1:* *

movie=aviread('f.avi');
movie(1)%%displays first frame's data%%
frame_nums=[1 2 3 4];
movie2=aviread('f.avi',frame_nums);%%reads the indexed frames%%
imshow(movie(1).cdata)
file_info=aviinfo('f.avi')
file_info.NumFrames%%gives us no. of frames in video%%
image_data=uint8(zeros(file_info.Height,file_info.Width,3,file_info.NumFrames));
for k=1:file_info.NumFrames
    image_data(:,:,:,k)=movie(:,:,:,k).cdata;%%error showing in this line%%
end

• * Method2: * *

workingDir=tempname;
mkdir(workingDir);
mkdir(workingDir,'images');
video=VideoReader('f.avi');
for ii = 1:4
    img = read(video,ii);
    % Write out to a JPEG file (img1.jpg, img2.jpg, etc.)
    imwrite(img,fullfile(workingDir,'images',sprintf('img%d.jpg',ii)));
end
img= im2double(img)
T=dctmtx(8);
dct2=T*img*T';
B=blockproc(img,[8 8],dct2);%%error in this line%%
mask = [1   1   1   1   0   0   0   0
        1   1   1   0   0   0   0   0
        1   1   0   0   0   0   0   0
        1   0   0   0   0   0   0   0
        0   0   0   0   0   0   0   0
        0   0   0   0   0   0   0   0
        0   0   0   0   0   0   0   0
        0   0   0   0   0   0   0   0];

Answer 1

[Walter Roberson]

image_data(:,:,:,k)=movie(k).cdata;

[Ravi]

Assignment has fewer non-singleton rhs dimensions than non-singleton subscripts

still error persists..Can any one help me?