Did you want to place the video on an axes with the app? Or do you want to place the video on an axes on a different UIFigure/app?
I attached an app assuming you want to place the video on axes within the app's canvas.
Either way, you will need to assign an axes to place your video. For the imshow() function, you can do this as such:
imshow(img,'Parent',app.UIAxes)
You can drag uicomponents (axes and pushbutton) onto the canvas. Then you can right click the pushbutton>Callback>Add PlayButtonPushed callback. I added some icons to make it more aesthetically pleasing.
if app.PlayButton.Text == "Play"
app.PlayButton.Text = "Stop";
app.PlayButton.Icon = "IconEnd.png";
aviObject = VideoWriter(['videolog.avi']); % Create a new AVI file
open(aviObject);
%for iImage = 1:200 % Capture X frames
tStart = tic;
tEnd = 0;
while tEnd < 30
timerVal = tic
% [img, ts] = snapshot(g);
img=rand(40); %Creating random matrix as I don't have the varibale g defined.
imshow(img,'Parent',app.UIAxes)
drawnow
writeVideo(aviObject, img); % Add the image to the AVI file
if app.PlayButton.Text == "Play"
disp('Loop stopped by user');
break;
end % end if
tEnd = toc(tStart)
end % end while or for
else
app.PlayButton.Text = "Play";
app.PlayButton.Icon = "IconPlay.png";
end
