Generating High Quality Movies

Jonas Larsson

I've spent the day trying to generate animations of an unsteady simulation of stator-rotor interaction in an axial turbine. It is quite easy to do in Fluent (I'll add a short description below for those who are interested in how it's done). However, I haven't been able to generate any high quality mpeg movies for use in a powerpoint presentation. Could anyone recommed which formats to export (tiff, ppm, ...?), which image size to use and which tools that are best at generating mpegs (mpeg_encode setting?) in order to get the best quality of the mpeg movies?

This is how I generate an animation:

1 Set up the view interactively as you want it.

2 Go to File/Hardcopy and set up the output format and size you want (I used tiff and 560x400 pixels)

3 Go to Solve/Monitors/Commands, add one comand to be performed every time-step. In the command field write a text comman which plots and saves what you want. Here is an example: /display contour pressure 0 300000 /display hard-copy ramp_%t.tiff

4 Run the unsteady simulation. This will generate a bunch of tiff files numbered by the time step (%t)

5 These tiff files can be viewed with the "animate" utility (part of ImageMagick, distributed with fluent in the contrib directory) by simply writing "animate *.tiff". This animation usually looks very good (if your simulation is good).

6 To create an mpeg I use the "mpeg_encode" utility also available in the contrib directory. To use this you have to write a parameter file though. My file looks something like this:

=== mpeg.params ===

BASE_FILE_FORMAT PPM

INPUT_DIR /disk/u43/yy10622/Fluent/Movies

INPUT

`ls *.tiff`

END_INPUT

INPUT_CONVERT convert -size 352x240 * ppm:-

PATTERN IBP

GOP_SIZE 15

SLICES_PER_FRAME 1

PIXEL HALF

RANGE 10

PSEARCH_ALG LOGARITHMIC

BSEARCH_ALG CROSS2

IQSCALE 6

PQSCALE 6

BQSCALE 6

REFERENCE_FRAME ORIGINAL

OUTPUT ramp.mpeg

===

To genereate the mpeg you the just run "mpeg_encode mpeg.params". The result can be viewed with mpeg_play.

However, the quality of the mpeg movie is always much worse than the "animate" command. Has anyone been able to generate mpeg movies from fluent that have the same quality as "animate" gives? I appreciate any help.