How to save video from satelliteScenarioViewer?

Is there a way to save the video when using the satelliteScenarioViewer in the Satellite or Aerospace Comm Toolbox?

I can play it fine on my workstation but I'd like to present some animated results in a slide presentation.

[Vinayak]

Hi,

We can record and save videos using the satelliteScenarioViewer in the Satellite or Aerospace Comm Toolbox in the following way.

% Create a satellite scenario
scenario = satelliteScenario;
% Add satellites, ground stations, etc. to the scenario

% Create a satellite scenario viewer
viewer = satelliteScenarioViewer(scenario);

% Set up the video recording
videoFile = 'scenario_video.mp4'; % Specify the name of the video file
videoWriter = VideoWriter(videoFile, 'MPEG-4'); % Create a VideoWriter object
videoWriter.FrameRate = 30; % Set the frame rate of the video
open(videoWriter); % Open the video writer

% Render and record each frame of the scenario
while viewer.isOpen()
    frameImage = frame2im(getframe(gcf)); % Get the current frame as an image
    writeVideo(videoWriter, frameImage); % Write the frame to the video file
    viewer.step(); % Advance to the next frame
end

% Close the video writer
close(videoWriter);

Thanks,

Vinayak

[Mike Powers]

Thanks Vinayak- when I run this code (in R2022b) I get an error:

"Unrecognized method, property, or field 'isOpen' for class 'matlabshared.satellitescenario.Viewer'."

[Brian LaRocca]

I would like the same functionality. But I am getting the same results as Mike. I tried using a for loop, e.g. for n = 1:10 ... end to get around that and just see some saved results. However, that does not work since the satellitescenario object does not have a "step" method.

Answer 1

[Saffan]

Hi Mike,

Currently, there is no direct way to save a video from “satelliteScenarioViewer”, but there is a workaround using the “VideoWriter” class to combine each frame into a video. We can utilize the “screencapture” method from the File Exchange to obtain the required frames. Here is an example code snippet:

% Create a Scenario and a Viewer
sc = satelliteScenario(startTime,stopTime,sampleTime);
viewer = satelliteScenarioViewer(sc);
% Specify the name of the video file
videoFile = 'scenario_video.mp4'; 
% Create a VideoWriter object
videoWriter = VideoWriter(videoFile, 'MPEG-4'); 
% Set the frame rate of the video
videoWriter.FrameRate = 30; 
% Open the video writer
open(videoWriter); 

h=findall(0, 'Type', 'figure', 'Name', 'Satellite Scenario Viewer');

for time=startTime:minutes(1):stopTime
    screencapture(h,'tempImg.png');
    % Get the current frame as an image
    frameImage = imread('tempImg.png'); 
    % Write the frame to the video file
    writeVideo(videoWriter, frameImage); 
    % Advance to the next frame
    viewer.CurrentTime=time; 
end
close(videoWriter);

You can choose the required playback speed of the simulation by setting the appropriate increment time in the ‘for’ loop.

Here is the link to “screencapture” method in File Exchange:

https://www.mathworks.com/matlabcentral/fileexchange/24323

Please refer to the following documentation for more information on “VideoWriter” class:

https://www.mathworks.com/help/releases/R2023a/matlab/ref/videowriter.html

Hope this helps!