optimization of Webcam livestream with overlays and keyboard button actions (low FPS, high CPU-Load)

Hi, i have a FullHD USB-Webcam and have performance problems with the FullHD-livestream with overlays and keyboard button actions. The stream has low fps, very high CPU-Load and sometimes the stream freezes. Can you please help me and give me tips on what the problem is?

% +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++%
% ----------------------- launch live stream ------------------------------%
  % get cam 1
  try
    params.cam = webcam(1);                 % uncomment only for test on laptop (HD-Ready Webcam)
    params.cam.Resolution = '1280x720';
%     params.cam = webcam(2);               %uncomment for FullHD USB-Webcam
%     params.cam.Resolution = '1920x1080';
  catch
    disp('active session already exist for cam 1')
  end

% some code stuff...
%...
  
% +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++%
% ----------------------- infinite loop for livestream --------------------%
  while true

    pause(0.001)
    params = get_params();
      
    try
      livestream_overlays(params);
    catch
      break;
      close all;
      pause(0.001)
    end

  end
  
  close all
  pause(0.001)
  
% some code stuff...
%...

% +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++%
% ----------------------- Live Stream functions ---------------------------%

function livestream_overlays(params)

  % - set yellow line and number of sheets as overlays

  params = overlay_base(params);

  % - set red lines as overlays

  if params.state == 1 || params.state == 2
    params = overlay_red(params);
  elseif params.state == 3
    params = overlay_blue(params);
  end

  % - set green lines as overlays

  if params.lvalue
    params = overlay_green(params);
  end

  % - show live stream frame with overlays

  set(params.aximg, 'CData', params.img);

  if params.spsn == 1
    set(params.aximg2, 'CData', params.img2);
  end
  
% some code stuff...
%...

[Walter Roberson]

If you have the Image Acquisition Toolbox, then possibly using videoinput() might do better than using webcam()

For example

vid = videoinput('macvideo', 1, 'YCbCr422_1280x720');
src = getselectedsource(vid);

vid.FramesPerTrigger = 1;

preview(vid);

[Tommy Schumacher]

thanks. Better for performance or what are real differences between those two?

[Walter Roberson]

Image Acquisition Toolbox has presumably been tuned for high performance.

I do not know enough about the code or the inner workings to know whether the pause(0.001) is having an impact. My inclination would be to comment it out.

[Walter Roberson]

Is FullHD a brand name, or is it just being used descriptively?

[Tommy Schumacher]

no its just 1920x1080.