SPMD Video Writing with dynamic frames

I want to write a video as follows:

• extract a plot of signal 1 (at given frame number) by calling another function
• extract a plot of signal 2 (at given frame number) by calling another function
• extract (at given frame number) the frame from a video object
• stitch the three together into a single image
• write (at given frame number) the image as a frame in a write video object

This has to be done for about 1500000 frames which is making the process very long. I have tried looking up spmd answers but I am unable to figure out how I would use it to write the video.

Answer 1

[Raymond Norris]

This might be an approach. Quite a bit of this is pseudo code and probably needs refining to synchronize the images into correct order.

Create a data queue (q) which is sent the image from the workers and writes the image into a video object.

v = VideoWriter(filename);
q = parallel.pool.DataQueue;
afterEach(q,@(an_image)writeImageToFrame(v,an_image));

parfor fidx = 1:1500000
    signal_1 = fnc1(fidx);
    signal_2 = fcn2(fidx);
    frame = video_obj(fidx);
    % Stitch the three together into a single image
    the_image = signal_1 + signal_2 + frame;
    send(q, the_image)
end

function writeImageToFrame(v,an_image)
    v.writeVideo(v,an_image)
end

Fill in the code above, post it (what's working, what's not) and we can refine it.