imshow shows rotated image

Question

I'm using Matlab to show the frames in a video sequence , below is my code:

seq=sprintf('walk%d.avi',v);   % video's name
videoReader = vision.VideoFileReader(seq);
vidObj = VideoReader(seq);
numFrames = vidObj.NumberOfFrames
for i = 1:numFrames 
    frame = step(videoReader); % read the next video frame
    imshow(frame)
end

Actually it worked fine previously, and i have no idea since when and what caused it to show rotated image . Hope you guys can help me. thank you.

Answer 1

Most updated Matlab function to vertically flip back the frame is:

FlippedFrame = flip(frame,1);