Approaches to create a video in matlab
There is http://www.mathworks.de/help/techdoc/ref/videowriterclass.html
My approach is to print the single frames/figures to png files using the print
function giving them filenames like 1.png, 2.png, ...
and then I use the free FFMPEG converter to make a video.
ffmpeg -r 20 -i %d.png foo.avi
This allows for a lot of finetuning, when it comes to the parameters of the conversion (bitrate, codec, geometry etc.).
Matlab has a built in 'movie' command to play movies. I find it pretty easy to work with. I've used it on plots to show changes in time, as well as individual images to make a real movie.
http://www.mathworks.com/help/techdoc/ref/movie.html
I believe the general procedure is:
for ii=1:100
plot(something(ii))
F = getframe;
end
movie(F)
To save a movie, you can use a similar procedure as above, but use the
writeVideo
command.
http://www.mathworks.com/help/techdoc/ref/videowriterclass.html
Here are some of the different ways to create movies in (core) MATLAB.
MOVIE2AVI
(deprecated, use VIDEOWRITER instead)
%# figure
figure, set(gcf, 'Color','white')
Z = peaks; surf(Z); axis tight
set(gca, 'nextplot','replacechildren', 'Visible','off');
%# preallocate
nFrames = 20;
mov(1:nFrames) = struct('cdata',[], 'colormap',[]);
%# create movie
for k=1:nFrames
surf(sin(2*pi*k/20)*Z, Z)
mov(k) = getframe(gca);
end
close(gcf)
%# save as AVI file, and open it using system video player
movie2avi(mov, 'myPeaks1.avi', 'compression','None', 'fps',10);
winopen('myPeaks1.avi')
AVIFILE
(deprecated, use VIDEOWRITER instead)
%# figure
figure, set(gcf, 'Color','white')
Z = peaks; surf(Z); axis tight
set(gca, 'nextplot','replacechildren', 'Visible','off');
%# create AVI object
nFrames = 20;
aviobj = avifile('myPeaks2.avi', 'fps',10);
%# create movie
for k=1:nFrames
surf(sin(2*pi*k/20)*Z, Z)
aviobj = addframe(aviobj, getframe(gca));
end
close(gcf)
%# save as AVI file, and open it using system video player
aviobj = close(aviobj);
winopen('myPeaks2.avi')
VIDEOWRITER
%# figure
figure, set(gcf, 'Color','white')
Z = peaks; surf(Z); axis tight
set(gca, 'nextplot','replacechildren', 'Visible','off');
%# create AVI object
nFrames = 20;
vidObj = VideoWriter('myPeaks3.avi');
vidObj.Quality = 100;
vidObj.FrameRate = 10;
open(vidObj);
%# create movie
for k=1:nFrames
surf(sin(2*pi*k/20)*Z, Z)
writeVideo(vidObj, getframe(gca));
end
close(gcf)
%# save as AVI file, and open it using system video player
close(vidObj);
winopen('myPeaks3.avi')
IMWRITE
(technically not a movie, but an animated GIF image)
%# figure
figure, set(gcf, 'Color','white')
Z = peaks; surf(Z); axis tight
set(gca, 'nextplot','replacechildren', 'Visible','off');
%# preallocate
nFrames = 20;
f = getframe(gca);
[f,map] = rgb2ind(f.cdata, 256, 'nodither');
mov = repmat(f, [1 1 1 nFrames]);
%# create movie
for k=1:nFrames
surf(sin(2*pi*k/20)*Z, Z)
f = getframe(gca);
mov(:,:,1,k) = rgb2ind(f.cdata, map, 'nodither');
end
close(gcf)
%# create GIF and open
imwrite(mov, map, 'myPeaks4.gif', 'DelayTime',0, 'LoopCount',inf)
winopen('myPeaks4.gif')