converting video to images by secends

Question

caesar 2017-12-8

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/371805-converting-video-to-images-by-secends

评论： KSSV 2020-1-30

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?

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

KSSV 2017-12-8

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/371805-converting-video-to-images-by-secends#answer_295281

在 MATLAB Online 中打开

Try this:

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