From: Diego on
Here You go, dude!

.....Construct a multimedia reader object associated with file xylophone.mpg with the user tag property set to 'myreader1'.

readerobj = mmreader('xylophone.mpg', 'tag', 'myreader1');

Read in all the video frames.

vidFrames = read(readerobj);

Find out how many frames there are.

numFrames = get(readerobj, 'numberOfFrames');

Create a MATLAB movie structure from the video frames.

for k = 1 : numFrames
mov(k).cdata = vidFrames(:,:,:,k);
mov(k).colormap = [];
end

Play back the movie once at the video's frame rate.

movie(mov, 1, readerobj.FrameRate);

There is no need to close an mmreader object, but when you are finished with it you can clear it from the workspace.

clear(readerobj)...... Matlab Help