From a time in a video, can you get the frame number?

I want to know what frame number we have from a video at certain time stamps. For example from 1:42 to 1:45 mark. How do I obtain this?

[Mathieu NOE]

hello

I suppose that you know the total number of frames and the start / end time stamps

then it's just a matter of linear interpolation

[Walter Roberson]

@Mathieu NOE

Knowing the total number of frames and the total video length and the start and end time stamps... assumes constant video frame timing.

If you do assume constant frame rate, then converting timestamp to frame number becomes possible by using the FrameRate property. However, if the frame rate is nominally 30 frames per second then the true frame rate might only be 29.97 frames per second, and it is questionable as to whether the header video frame rate will be 30/1 or 2997/100 or 30000/1001

Answer 1

[SACHIN KHANDELWAL]

Hi @Happy PhD,

Assuming that you want to get the number of frames in a video file using MATLAB, the following MATLAB Answers posts might be helpful for you:

https://www.mathworks.com/matlabcentral/answers/250033-number-of-frames-in-video-file-with-matlab-2015b#answer_196870

https://www.mathworks.com/matlabcentral/answers/123189-get-the-number-of-frame-of-a-video-using-vision-videofilereader-and-videoreader

Also, check out the official documentation for: https://www.mathworks.com/help/matlab/ref/videoreader.html

If this does not resolve the issue, could you please include your files and a more detailed problem statement? This will help in providing a more specific solution.