Daniel,
Please see the files attached and the code below. Saving the video should be faster when the figure's "Visible" property is set to "off" and when running it on a .m script instead of the Live Script.
Setup Figure
figure("Visible","off")
tiledlayout(2,1)
%setup subplots
ax1 = nexttile; % For video
ax2 = nexttile; % For data plot
%setup videoreader object
CH47Landing = 'xylophone.mp4';
v = VideoReader(CH47Landing);
nFrames = v.Duration*v.FrameRate; % Number of frames
% Display the first frame in the top subplot
vidFrame = readFrame(v);
image(vidFrame, 'Parent', ax1);
ax1.Visible = 'off';
%Load Data
lt = seconds(v.CurrentTime:1/v.FrameRate:v.NumFrames/v.FrameRate); %Note, this video is in seconds, so datetime was not used
y = rand(v.NumFrames,1)*15;
nDataPoints = length(lt); % Number of data points
step = 0.033; % Increase this value to get a higher plot rate
index = 1:step:nDataPoints;
ii = 2;
% Diplay the plot corresponds to the first frame in the bottom subplot
h = plot(ax2,lt(1:floor(index(ii))),y(1:floor(index(ii))),'-k');
%Fix the Axes
ax2.XLim = [lt(1) lt(end)];
set(gca, 'YDir','reverse')
ylim(ax2,[0 15])
title('CH47; 31Jan23; h(i)=70cm; AirT=18°F. PT=#5')
ylabel(ax1,'Deflection (mm)')
Save one frame at a time
vsave = VideoWriter('SavedFilebyFrame','MPEG-4');
h = plot(ax2,lt(1:floor(index(ii))),y(1:floor(index(ii))),'-k');
% lt = datetime(lt,'ConvertFrom','datenum','Format','HH:mm:ss.SSS');
open(vsave)
%Animate
while hasFrame(v)
vidFrame = readFrame(v);
image(vidFrame, 'Parent', ax1);
ax1.Visible = 'off';
ii = ii + 1;
set(h,'YData',y(1:floor(index(ii))), 'XData', lt(1:floor(index(ii))))
xlim(ax2,[0 max(h.XData)])
ylabel(ax1,'Deflection (mm)')
img = getframe(gcf);
writeVideo(vsave,img.cdata)
end
close(vsave)
Save entire video at once
Create 4D matrix of video
ii=0;
v = VideoReader(CH47Landing);
lt = 1/v.FrameRate:1/v.FrameRate:v.NumFrames*v.FrameRate;
while hasFrame(v)
ii = ii + 1;
vidFrame(:,:,:,ii) = readFrame(v);
end
Write video
figure("Visible","off")
vsave = VideoWriter('SavedFile','MPEG-4');
h = plot(ax2,lt(1:floor(index(ii))),y(1:floor(index(ii))),'-k');
% lt = datetime(lt','ConvertFrom','datenum','Format','HH:mm:ss.SSS');
open(vsave)
for ii = 1:v.NumFrames
% pause(1/v.FrameRate);
image(vidFrame(:,:,:,ii), 'Parent', ax1);
ax1.Visible = 'off';
set(h,'YData',y(1:floor(index(ii))), 'XData', lt(1:floor(index(ii))))
xlim(ax2,[0 max(h.XData)])
img = getframe(gcf);
writeVideo(vsave,img.cdata);
end
close(vsave)
