The problem

The Data Analysis & Visualization Services of the Swiss National Supercomputing Centre (CSCS) helps the Swiss research community to present and visually explore the results of their studies. One of the services most requested is the production of movies from simulation results, especially from Molecular Dynamics. The computation platform is normally Linux, but the platform on which the movies are viewed is mostly Windows.

Those requirements made me explore various options, and mencoder application has been the best one found. So I started various test to find the best parameters and setup for our needs.

An accompanying page explains the interfacing of mencoder to the AVS/Express visualization system. Here are some examples of chemistry visualizations done here.

Testing conditions

mplayer and mencoder 1.0pre3
Linux RedHat 7.3
816 JPEG frames 512x512
Two pass encoding with image fps set to 10

Image characteristics

Here is an example of the images involved. Unfortunately the full set of images cannot be made available because the research results have not yet been published.

The images have a lot of sharp edges that move and disappear.

Microsoft MPEG4 V2 codec testing

To create movies compatible with the PC Windows platform we are forced to use the Microsoft MPEG4 V2 codec that is present on every Windows machine. Instead the better MPEG4 codec requires the installation of the DivX codec (from www.divx.com).

Here you find:

The test results. No text after Pass 1: and Pass 2: labels means that mencoder crashed.
The testing script
The helper script that performs one single test step.

From the testing the following set of parameters seem the best for this particular set of frames:

lavcopts="vbitrate=2160000:mbd=2:keyint=132:vqblur=1.0:cmp=2:subcmp=2:dia=2:mv0:last_pred=3"

MPEG4 codec testing

No test has been performed yet. For now the following set of parameters has been acritically used:

lavcopts="vbitrate=2160000:mbd=2:keyint=132:v4mv:vqmin=3:vlelim=-4:vcelim=7:lumi_mask=0.07:dark_mask=0.10:naq:\
          vqcomp=0.7:vqblur=0.2:mpeg_quant"

I have found interesting also the following set of parameters:

lavcopts="vbitrate=2160000:mbd=2:keyint=132:v4mv:vqmin=3:lumi_mask=0.07:dark_mask=0.2:mpeg_quant:scplx_mask=0.1:\
          tcplx_mask=0.1:naq"