how to track objects in a live video

By using this code, when I show the image of the object in a phone it tracks its name but when i show a video then it can not identify the object, what's wrong in the code. I think I am going wrong in the third line i-e (snapshot(camera)). Please help me what to add or remove in this code.

camera = webcam; % Connect to the camera
load("trained filename")   
    im = snapshot(camera);       % Take a picture
    image(im);                   % Show the picture
    im = imresize(im,[224 224]); % Resize the picture for alexnet
        
    label = classify(netTransfer,im);    % Classify the picture
    title(char(label));          % Show the class label

Answer 1

[Image Analyst]

snapshot gets a frame from a camera. If you want to read from a video you need to call VideoReader. See some attached demos.