Creating MPEG animations using xfpp3d / xflat2d

The visualization utilities xfpp3d and xflat2d both have a box-less button labelled Mpeg located near the upper right of their respective GUIs. Clicking on the button will bring up the mpeg window:

• Name: This text type-in specifies the name of the mpeg file that is to be generated. The file name must have an extension .mpg, .MPG, .mpeg or .MPEG.
  
  
• WD: This text type-in specifies the directory in which the mpeg file is to be created. The (temporary) jpeg-format images that are used in the generation of the animation are also stored in this directory.
  
  
• Seq No.: This output-only text widget displays the sequence number for the next jpeg-format image that will be created in record mode.
  
  
• Control: This set of radio buttons controls the creation and playback of mpeg animations as follows:
  
  
  • Off: When this button is pressed, recording of images is disabled. This is the default mode of operation.
    
    
  • Record: When this button is pressed, and when the main GUI's Pause button is not activated, every refresh (redisplay) of the main GUI graphics window will result in the capture of the graphics area as a jpeg image with a filename <Name>.<Seq. No.>.jpg, followed by an incrementing of Seq. No..
    
    
  • Generate: Pressing this button will result in the generation of an mpeg animation with filename Name using the jpeg images with sequence numbers from 1 to Seq. No. - 1 that were previously created via the Record operation. The user is prompted to confirm overwrite if the generate will clobber an existing file.
    
    
  • Playback: When this button is pressed, mpeg_play is invoked to play back the mpeg animation, Name.
  
  
• The output-only browser area at the bottom of the panel displays all mpeg files contained in the working directory. The file corresponding to Name, should it exist, is highlighted in red.

Following is a recommended sequence of operations for the creation of an animation using either of the two utilities:

1. Prepare the data to be animated via a user program and redirection of standard output to a file. This will in general include a choice of an appropriate number of time steps for the animation.
2. Start xflat2d / xfpp3d with standard input redirected from the file generated in the previous step. Keeping the Pause button activated, adjust the view of the data (using Zoom in/out, Tumble speed etc.) as appropriate.
3. Bring up the mpeg panel, and depress Record.
4. Deactivate the Pause button in the main GUI to initiate the recording process.
5. When all time steps of the data have been visualized, reactivate the Pause function.
6. Press Generate on the mpeg panel to make the mpeg animation.
7. Press Playback to verify that the animation was properly created.