Development Environment

Exporting MATLAB Graphs in AVI Format

In MATLAB, you can save a sequence of graphs as a movie that can then be played back using the movie function. You can export a MATLAB movie by saving it in MAT-file format, like any other MATLAB workspace variable. However, anyone who wants to view your movie must have MATLAB. (For more information about MATLAB movies, see the Animation section in the MATLAB Graphics documentation.)

To export a sequence of MATLAB graphs in a format that does not require MATLAB for viewing, save the figures in Audio Video Interleaved (AVI) format. AVI is a file format that allows animation and video clips to be played on a PC running Windows or on UNIX systems.

Creating an AVI Format Movie

To export a sequence of MATLAB graphs as an AVI format movie, perform these steps:

1. Create an AVI file, using the avifile function.
2. Capture the sequence of graphs and put them into the AVI file, using the addframe function.
3. Close the AVI file, using the close function, overloaded for AVI files.

Note    To convert an existing MATLAB movie into an AVI file, use the movie2avi function.

For example, this code example exports a sequence of MATLAB graphs as the AVI file mymovie.avi.

• aviobj = avifile('mymovie.avi','fps',5); 
  
  for k=1:25
      h = plot(fft(eye(k+16)));
      set(h,'EraseMode','xor');
      axis equal;
      frame = getframe(gca);
      aviobj = addframe(aviobj,frame);
  end
  
  aviobj = close(aviobj);
  

Note the following items in this code example:

• The avifile function creates an AVI file and returns a handle to an AVI file object. AVI file objects support properties that let you control various characteristics of the AVI movie, such as colormap, compression, and quality. (See the avifile reference page for a complete list.) avifile uses default values for all properties, unless you specify a value. In the example, the call to avifile explicitly sets the value of the frames per second (fps) property.
• The example uses a for loop to capture the series of graphs to be included in the movie. You typically use addframe to capture a sequence of graphs for AVI movies. However, because this particular MATLAB animation uses XOR graphics, you must call getframe to capture the graphs and then call addframe to add the captured frame to the movie. See the addframe reference page for more information.
• The example calls the close function to finish writing the frames to the file and to close the file.

Exporting Binary Data

Importing HDF Data