VMD-L Mailing List

From: John Stone (johns_at_ks.uiuc.edu)
Date: Wed May 16 2007 - 14:44:17 CDT

Hi,
  The display rate of VMD is limited by the speed of your graphics
board (GPU). The display rate of the movie is set by the video encoder,
and in the case of standard PAL and NTSC movie formats, this is either
24, 25, 29.97, or 30 frames per second. The movie maker plugin for VMD
uses 24 FPS when encoding MPEG movies, so presumably the large speed difference
you observed in the rate of movie playback versus what you see in VMD just
indicates that when you're displaying interactively in VMD, that your
graphics card is only achieving something on the order of 8 FPS.
If you had a 500 frame trajectory, the longest that movie can run
with no duplication of video frames, is just over 20 seconds, assuming
you encoded it as an MPEG movie with the normal 24 frames per second rate
that the plugin uses by default. Can you verify that your movie contains
all 500 frames? (mplayer and/or other movie player tools can tell you
how many frames are in the movie, the frame rate, etc)

Cheers,
  John Stone
  vmd_at_ks.uiuc.edu

On Wed, May 16, 2007 at 05:49:50PM +0100, Kailee wrote:
> Dear VMD users,
>
> I am trying to use VMD to make movie from AMBER trajectory files after MD, I
> can make a movie using the movie generator in VMD, however, I found that the
> atom moves much faster than that viewed using VMD. For example, I have 500
> frames in total, and when I use VMD to view this trajectory, it cost about
> 40 seconds to finish from frame 1 to frame 500, but when I set the movie
> duration as 40 seconds in the movie generator, it is actually within only 10
> seconds to go from frame 1 to frame 500, therefore in the 40 seconds movie I
> have made, it played 4 times the trajectory and all the atoms move much
> faster. Can anyone tell me what's wrong with this and how should I make a
> right movie?
>
> Thank you for any suggestion.
>
> Kailee 

-- 
NIH Resource for Macromolecular Modeling and Bioinformatics
Beckman Institute for Advanced Science and Technology
University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
Email: johns_at_ks.uiuc.edu                 Phone: 217-244-3349
  WWW: http://www.ks.uiuc.edu/~johns/      Fax: 217-244-6078