How to turn a movie into a gif?

Question

Connor Davis 2024-9-22

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2154680-how-to-turn-a-movie-into-a-gif

评论： DGM 2024-9-23

Hi,

I am trying to turn this script into a .gif file. I tried using movie2gif, imwrite, and write but was unsuccesfull. Below is the script. Any help would be greatly appreciated.

% Bounds and resolution of mesh
x=0:0.1:10;
t=0:300:10000;
[X,T]=meshgrid(x,t);
% Constants
i=sqrt(-1);
a=10; % Angstroms
m=9.1*(10^-31); % Kg
h_bar=1.05*(10^-34); % J*s
% Energy Levels
E_1=((pi*h_bar)^2)/(2*m*a^2);
E_2=((4*pi*h_bar)^2)/(2*m*a^2);
E_3=((9*pi*h_bar)^2)/(2*m*a^2);
% Wavefunction
psi=sqrt(1/3).*(exp(-i*T*E_1/h_bar).*sin(pi*X/a)+exp(-i*T*E_2/h_bar).*sin(2*pi*X/a)+exp(-i*T*E_3/h_bar).*sin(3*pi*X/a));
% Modulus of wavefunction
mod=conj(psi).*psi;
% Functions to be plotted
u_1=real(mod);
u_2=real(psi);
u_3=imag(psi);
% Capturing frames
F(length(t))=struct('cdata',[],'colormap',[]);
for i=1:length(t)
    plot(x,u_1(i,:),'linewidth',1.5);
    hold on
    plot(x,u_2(i,:),'linewidth',1.5);
    plot(x,u_3(i,:),'linewidth',1.5);
    hold off
    xlabel('Postion Inside infinite square well (Å)');
    legend('|\psi(x,t)|^2', 'Re(\psi)', 'Im(\psi)');
    axis([min(x) max(x) min(min(u_3)) max(max(u_1))]);
    F(i)=getframe;
end
close
movie(F,0)
Warning: Movie requested to play 0 times

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Answer 1

Walter Roberson 2024-9-22

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2154680-how-to-turn-a-movie-into-a-gif#answer_1520810

在 MATLAB Online 中打开

Before the for i loop insert

filename = 'Output.gif';

Change

F(i)=getframe;

to

F(i)=getframe;
if i == 1;
    SZ = size(F(1).cdata);
    imwrite(F(1).cdata, filename, 'writemode', 'overwrite');
else
    F(i).cdata = imresize(F(i).cdata, SZ);
    imwrite(F(i).cdata, filename, 'writemode', 'append');
end

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DGM 2024-9-23

在 MATLAB Online 中打开

Need to convert the frames to indexed color. Probably should also set frame delay and loop count.

By default, getframe() grabs the current axes. If you want the axis labels, title, or ticks, you'll need to specify the figure instead.

% Bounds and resolution of mesh
x=0:0.1:10;
t=0:300:10000;
[X,T]=meshgrid(x,t);
% Constants
i=sqrt(-1);
a=10; % Angstroms
m=9.1*(10^-31); % Kg
h_bar=1.05*(10^-34); % J*s
% Energy Levels
E_1=((pi*h_bar)^2)/(2*m*a^2);
E_2=((4*pi*h_bar)^2)/(2*m*a^2);
E_3=((9*pi*h_bar)^2)/(2*m*a^2);
% Wavefunction
psi=sqrt(1/3).*(exp(-i*T*E_1/h_bar).*sin(pi*X/a)+exp(-i*T*E_2/h_bar).*sin(2*pi*X/a)+exp(-i*T*E_3/h_bar).*sin(3*pi*X/a));
% Modulus of wavefunction
mod=conj(psi).*psi;
% Functions to be plotted
u_1=real(mod);
u_2=real(psi);
u_3=imag(psi);
% gif parameters
filename = 'test.gif';
fdelay = 0.05;
loopcount = Inf;
% Capturing frames
for i=1:length(t)
    plot(x,u_1(i,:),'linewidth',1.5);
    hold on
    plot(x,u_2(i,:),'linewidth',1.5);
    plot(x,u_3(i,:),'linewidth',1.5);
    hold off
    xlabel('Postion Inside infinite square well (Å)');
    legend('|\psi(x,t)|^2', 'Re(\psi)', 'Im(\psi)');
    axis([min(x) max(x) min(min(u_3)) max(max(u_1))]);
    
    % i'm assuming that we don't need to keep the frames
    % also assuming that frame size variation can be better solved 
    % either through managing the figure setup,
    % or by doing post-capture padding on the entire frame stack.
    thisframe = frame2im(getframe(gcf));
    [thisframe CT] = rgb2ind(thisframe,256);
    if i == 1
        imwrite(thisframe, CT, filename, 'writemode', 'overwrite', ...
            'delaytime',fdelay,'loopcount',loopcount);
    else
        imwrite(thisframe, CT, filename, 'writemode', 'append', ...
            'delaytime',fdelay);
    end
end
close