Movie Recorder

Movie Recorder captures image frames from Chimera and assembles them into a movie file. There are several ways to start Movie Recorder, a tool in the Utilities category. Movie Recorder is also implemented as the command movie. Movies of trajectories can be recorded with MD Movie.

Operations in Chimera can be performed interactively or with a script such as a command file (see an example command file). Certain commands are especially useful for scripting continuous motion. The frame rate in Chimera is nominally 30/s, but is performance-limited (may be slower depending on what is displayed and what hardware is being used). Saving frames will slow the process further, but this slowing will not affect the playback frame rate of the resulting movie (default 25/s). Thus, movie playback may be faster or slower than the original process in Chimera.

Frames should be captured with the dimensions desired for the resulting movie. Before frame capture, the window can be resized manually or by selecting a preset from the Movie Options. While not required, any specification of a preset or adjustment in the Frame Options for image file name, location, and format must be done before recording is started. During recording, other windows should not be placed over the Chimera graphics window.

On the Movie Recorder dialog, clicking Record initiates frame capture and changes the button to Stop. Clicking Stop halts frame capture, which can be restarted by clicking Record again. This can be repeated until the desired segments have been saved. Reset resets the frame count to zero and (unless Save images on Reset has been turned on) deletes the frames.

When the desired frames have been saved, the next step is to specify the movie Output file name/location and Output format:

• MPEG-1 [.mpg]
• MPEG-2 [.mpg]
• MPEG-4 [.mp4]
• AVI MSMPEG-4v2 [.avi]
• Quicktime [.mov] (default, unless a preset has been chosen)

• Frame Options
  • Directory - image file location
  • Filename pattern - string for naming image files
  • Format - image file format
    • JPEG [.jpeg]
    • PPM [.ppm]
    • PNG [.png] (default)
  • Save images on Reset - whether to keep individual image files when a reset occurs

• Movie Options
  • Bit rate (controls movie quality and file size):
    • Constant bit rate (Kbits/s) (default) - encode the movie to play back with a constant data rate. Generally, 200 Kbits/s is a low rate, 1000 medium, and 6000 high (default 2000). Increasing the bit rate increases movie quality and file size for a given resolution (window size) and frame rate. At a given bit rate, a larger window and/or a higher frame rate correspond to lower movie quality.
    • Variable bit rate. Q (1-31) - encode the movie to play back with a variable data rate specified with a quality factor, Q. The quality factor can range from 1 (highest quality and highest data rates) to 31 (lowest quality) (default 5). Some movie players may not handle variable bit rates correctly, yielding uneven playback.
  • Frames per second (default 25) - movie playback rate in terms of image frames
  • Buffer size (Kbytes) (default 200)
  • Set standard format - whether to use a preset with a built-in set of parameters:
    • VCD (Video Compact Disc) - MPEG-1, resolution 352x240, bit rate 1150 Kbits/s, buffer size 40 Kbytes
    • SVCD (Super Video Compact Disc) - MPEG-2, resolution 480x480, bit rate 2040 Kbits/s, buffer size 224 Kbytes
    • DVD (Digital Versatile/Video Disc) - MPEG-2, resolution 720x480, bit rate 6000 Kbits/s, buffer size 224 Kbytes
    Choosing a preset will resize the graphics window and adjust other parameters accordingly. Parameters can be readjusted after a preset has been chosen, however.