Writing a plot into a video

Hello all,

I have this code for generating plots with complete dark and green rectangular. I wanted to get the frames and save them into video. How do i do this?

clear all
clc

repeats=5;
x=[3 7 7 3];
y=[3 3 7 7];

plot(x,y);
set(gca,'color','k','XTick',[], 'YTick', [])
set(gcf, 'WindowState', 'maximized')

for k=1:repeats
        fill(x,y,'k')
        set(gca,'color','k')
        ax=gca;
        xlim([0 10]);
        ylim([0 10]);
        pause(5)
                fill(x,y,'g')
                set(gca,'color','k')
                ax=gca;
                xlim([0 10]);
                ylim([0 10]);
                pause(5)  
                F(k)=getframe(gcf);        
end

close all
writerObj=VideoWriter('safeGreen.avi','Uncompressed AVI');
writerObj.FrameRate=30;
open(writerObj);
writeVideo(writerObj,F);
close(writerObj);

[Walter Roberson]

That seems to be what you are doing already, except that you are only saving the green frames because you do not have a getframe() between the time you fill with black and the time you fill with green.

[Yanjika O]

I tried that. Didn`t make any difference.

[Walter Roberson]

I suspect that you want the frames you draw to last 5 seconds each upon display.

In order to do that at 30 fps, you would have to record 150 copies of the same frame.

Alternately, you can switch to 1/5 fps, like in the below code.

repeats=5;
x=[3 7 7 3];
y=[3 3 7 7];

plot(x,y);
set(gca,'color','k','XTick',[], 'YTick', [])
set(gcf, 'WindowState', 'maximized')

for k=1:2:repeats*2
    fill(x,y,'k')
    set(gca,'color','k')
    ax=gca;
    xlim([0 10]);
    ylim([0 10]);
    pause(1)
    F(k)=getframe(gcf);
    
    fill(x,y,'g')
    set(gca,'color','k')
    ax=gca;
    xlim([0 10]);
    ylim([0 10]);
    pause(1)
    F(k+1)=getframe(gcf);
end

close all
writerObj=VideoWriter('safeGreen.avi','Uncompressed AVI');
writerObj.FrameRate=1/5;
open(writerObj);
writeVideo(writerObj,F);
close(writerObj);

[Yanjika O]

Wow, I wish I could be so easy as you to understand and correct this as needed. It was really helpful Thank you~

Answer 1

[Image Analyst]

See my attached demo.