How can I have a video ouput with my code?

Hi, I was recently helped with detecting a line in an image. I have made some changes and I wan't to have a video input in stead of an image. Unfortunately, when I put a video input it just gives me the videoscreen as a picture. Underneath I have displayed the Simulink model. The structure is as follow:

Video --> Find line (doellijndetectie) --> find circles --> display to video

The aim of this code is to find the soccerline and the football and determine if it's a goal or not

My first code in "doellijndetectie" is a code that is an extrinsic and recalls a Matlab code:

function stop=doellijndetectie(veld)
% sizing van uitgang sz = size(u); 
%y=veld;
% hele functie is extrinsic: 
coder.extrinsic('Doellijn2'); 
%functie oproep: DOELLIJN2
Doellijn2(veld);
stop=veld;

Above is the extrinsic that calls the following code:

function y=Doellijn2(I)
%%%y size declareren
y=(I);
% Foto goal inlezen
%I = imread('strafschopgebied.png');
Igray = rgb2gray(I);
% Het zwarte gebied eruit filteren dat dichtbij BoundingBox zit
BW = imbinarize(Igray);
BW = imclearborder(~BW);
stats = struct2table(regionprops(BW));
ratio = stats.Area./(stats.BoundingBox(:,3).*stats.BoundingBox(:,4));
[~, idx] = max(ratio);
stats = stats(idx,:);
% GoalLijn (= Onderrand van BoundingBox)
goalLijn = [...
  stats.BoundingBox(1),stats.BoundingBox(2)+stats.BoundingBox(4);
  stats.BoundingBox(1)+stats.BoundingBox(3),stats.BoundingBox(2)+stats.BoundingBox(4)];
y1 = stats.BoundingBox(1);
x1 = stats.BoundingBox(2)+stats.BoundingBox(4);
x2 = y1 + stats.BoundingBox(3); 
y2 = x1 + stats.BoundingBox(4);

% Presentatie van het resultaat
figure
imshow(I)
hold on
y=plot(goalLijn(:,1),goalLijn(:,2),'c','LineWidth',4)
message = sprintf(['The value for x1: %f' 'The value for x2: %f' 'The value for y1: %f' 'The value for y2: %f'],[x1 x2 y1 y2])
uiwait(helpdlg(message));

The the "findCircles" code is:

function output_image = findCircels(Gevoeligheid,stop,StraalMin,StraalMax)
%#codegen
output_image = stop;
coder.extrinsic('imfindcircles');
[centers,radii] = imfindcircles(stop,[StraalMin, StraalMax], 'ObjectPolarity','dark', 'Sensitivity',Gevoeligheid,'Method','twostage');
stop = insertShape(stop,'Circle',[centers radii],'LineWidth',5);
output_image = stop;

When I press on play in Simulink it goes on and on in a loop.. and I get the following outputs:

Output 2 if from the Matlab function "Doellijndetectie"

I only need a video output that let's me know if it's a goal or not. I already have the line coordinates (almost the ball..)