converting video to images by secends

Hi I am trying to convert a video( MP4) to images such that the number of resulted images are same as the length of the video in seconds. for example, 2 minutes video would be 120 images each image is representing one second shot from the video. i have tried the following code

%

path = fullfile('C:\','Users','user','Downloads','data_test','videos');

movieFullFileName = fullfile(path, 'GP020165.mp4');

v = VideoReader(movieFullFileName)

D=v.Duration

[path, baseFileName, extentions] = fileparts(movieFullFileName);

path = pwd;

outputFolder = sprintf('%s/Movie Frames from %s', path, baseFileName);

if ~exist(outputFolder, 'dir')

      mkdir(outputFolder);

end

for k = 1:D  

    this_frame = readFrame(v);

outputBaseFileName = sprintf('Frame %4.4d.jpg', k);

outputFullFileName = fullfile(outputFolder, outputBaseFileName);

   imwrite(this_frame, outputFullFileName, 'jpg')
  end

Although I got the correct number of images, the division was based on the frame (considering the video frame rate was 30FPS) so I ended up losing almost 80% percent of the video content.

I think the problem is in these lines

for k = 1:D

this_frame = readFrame(v);

any suggestion about what to change in the code above?

Answer 1

[KSSV]

Try this:

vidObj = VideoReader('myvideopath');
numFrames = 0;
while hasFrame(vidObj)
    F = readFrame(vidObj);    
    numFrames = numFrames + 1;   
    imagesc(F)
    drawnow
end
numFrames

[caesar]

thanks KSSV for your answer, I tried it and it counts the number of frames. I am afraid that's not what I need at the moment. assume I have 4 seconds long video with 30 fps frame rate, I want to convert it to 4 images, one at each second of the video. what I have got is an image at each frame so instead of 4 images I ended up with ~ 120 images.

[Saif Sayed]

Undefined function 'hasFrame' for input arguments of type 'VideoReader'.

Error in VIDEO (line 3)

while hasFrame(vidObj)

can someone sort this error

[KSSV]

hasFRame is introduced in 2014b.....what version you are using?