How to replace a frame (rgb image) in a small video sequence ?

I want to replace a single rgb frame in a 4 sec video sequence, example i want to replace the 5th frame with my rgb image of same dimension as the video dimension (example 256x256)

Answer 1

[Walter Roberson]

    vid = 'NameOfTheVideo.avi';

    obj = VideoReader(vid);
    newobj = VideoWriter('NameOfNewVideo.avi', 'Uncompressed AVI');

    replacement_frame_5 = randi([0 255], 256, 256, 3, 'uint8');   %or as appropriate

    fr = 0;
    while hasFrame(obj)
        fr = fr + 1;
        a = readFrame(obj);
        if fr == 5
           a = replacement_frame_5;
        end
        writeVideo(newobj, a);
    end

    close(newobj);
    clear obj

[raviraja]

Hi Mr. Walter, thanks for the help with minor modification it works just fine, after replacing the frame in video how to display the video ? I used implay but it showing me some error I am attaching the screenshot here can you suggest me here,, I saved the video file in 'writer' variable name attaching that variable data also again thanks for the help...

[Walter Roberson]

It is not possible to play a video writer object. Once the video writer object is closed, use one of the techniques to play the video by name. Or create a video player object and step(player, a) as you go through outputting the frames to the video writer object.