writevideo skipping last frame

I am using writevideo to make a movie while creating the images. I have gotten it to work before however, this time it is skipping the last frame although I haven't changed the code. the code is:

if true
    narr_anim(7) = struct('cdata',[],'colormap',[]);                    
    myVideo = VideoWriter('dove_anim.avi');
    myVideo.FrameRate = 1;  
    open(myVideo);
    for m = 1 : 7
      narr_anim(m) = getframe(gcf)
      writeVideo(myVideo, narr_anim);
    end
    close(myVideo);
end

Am I missing something?

Answer 1

[Ben11]

Maybe use

narr_anim(m).cdata

in your loop? Other than that your code looks fine to me

[Leyon]

When playing the video in mediaplayer the video goes black before the last frame. All frames are printed to the screen. When I add your suggestion it gives:

if true
   If the colormap field is empty in a frame, cdata must contain an RGB image.
end

Do I need probably need a pause in the writing. My loop is actually two loops. I provided the inner loop.

[Leyon]

It seems the problem is with windows media player. When I play the video in realplayer it shows all frames correctly. I guess mediaplayer isn't holding for the last frame.

[Ben11]

ok glad it worked! What windows media player does is kind of weird though.

[Leyon]

Running the latest version. Version 12.0.7601.18150 on Windows 7 Pro

[Ben11]

what about vlc?

[Leyon]

vlc doesn't even play the video. It opens the first frame, runs the length of the movie but doesn't show the other images.

[Leyon]

videowriter captured all the frames and if I stop WMP it shows the last frame. But during playback, WMP goes black before the last frame is rendered.