all video frames are black

I am trying this code , it work with me for som videos , but for the other one I get all frames: black

Any idea about how I can solve this ?

I try to convert it to avi but I get the same, and I couldn't attach it here because it is too large

vidObj = VideoReader('002.mp4');
s = struct('cdata',zeros(vidObj.Height,vidObj.Width,3,'uint8'),'colormap',[]);
>> vidObj.CurrentTime = 0.6;
>> k = 1;
while vidObj.CurrentTime <= 0.9
    s(k).cdata = readFrame(vidObj);
    k = k+1;
end
whos s

[Walter Roberson]

It is not certain that the mp4 you are reading in is RGB; it could be grayscale or pseudocolor.

[Roaa Alnafea]

Thank you , it is RGB , I try to run the code in MATLAB online with the same file and it works !

[Benjamin Thompson]

Can you post a couple of the frames that you get from VideoReader, as a MAT file? Why do you need the 'colormap' stuff and please post the code that you use to display the frames in the structure s.