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Old   January 19, 2000, 12:07
Default Generating High Quality Movies
  #1
Jonas Larsson
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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.

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Old   January 19, 2000, 20:36
Default Re: Generating High Quality Movies
  #2
Arthur Valais
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I once tried to doing this... Nb. using NT platform

1. I saved them as tif 2. Converted to bmp 3. Used bmp2avi (a free util I found floating on the web)

This is as far as I got. However I also found a free avi2mpg (mpeg1) which reencodes the file though doesn't compress it (which is why I think you want mpg).

A thing I found early one is make sure the minimum and maximum contours levels were constant, otherwise the animation is not a true description.

Hope this helps,

Arthur Valais
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Old   January 20, 2000, 15:39
Default Re: Generating High Quality Movies
  #3
Kai Kang
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Check out at http://www.jasc.com they have a small and yet very easy-to-use package called animationshop (download cost abour USD40).

you can create top quality avi file directly from Tiff hardcopies from Fluent, which can be either put into ppt or view on any PC with windows installed...
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Old   January 20, 2000, 16:04
Default Re: Generating High Quality Movies
  #4
Jonas Larsson
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Did the final movie have good quality? Was it comparable to the quality you get by using "animate" directly on the tiff files?
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Old   January 20, 2000, 16:06
Default Re: Generating High Quality Movies
  #5
Jonas Larsson
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Is the quality of the final avi movie as good as what you get if you run "animate" directly on the tiff files?
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Old   January 20, 2000, 16:39
Default Re: Generating High Quality Movies
  #6
Kai Kang
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Try download animationshop (fully-function 30days trial) and see if the quality is good enough. I never did that in Fluent so I cann't tell you if any difference.
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Old   January 28, 2000, 15:39
Default Re: Generating High Quality Movies
  #7
Chris
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Jonas wrote:
> 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?

MPEG may not be the best choice if image quality (rather than file size) is the most important issue. MPEG, much like the JPEG image format, is a "lossy" format: it allows the image data to be modified in order to gain better compression. The modifications are typically not significant for tv/movie type video streams, due to the relatively smooth gradations in color across small areas of the images.

Computer generated images typically have very sharp, distinct (single pixel wide) color variations and are handled poorly by MPEG.

If you are happy with the quality of individual frames, you may want to simply combine the frames into a single multiframe file using GIF or MIFF (ImageMagick) format. The ImageMagick convert program should handle that. If you are on MS Windows, you can try AVI using some of the free/shareware AVI encoders available.
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Old   January 31, 2000, 05:31
Default Re: Generating High Quality Movies, Conclusions
  #8
Jonas Larsson
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Arthur, Kai and Chris - many thanks for your help. I've finally managed to create a high-quality movie from Fluent that will play well on a windows laptop. Here are a few points about the lessons I learned:

1. Displaying the images directly with the ImageMagick "animation" utility distributed with Fluent works well on a high-end workstation, but on an ordinary laptop (running linux) it doesn't work due to memory and speed limitations.

2. With the mpeg_encode utility distributed with Fluent you can create an mpeg movie (see my previous post). This will play on a PC, but the quality is not good at all.

3. Animation Shop Pro, as suggested by Kai, probably works well to create an avi movie. However, I had problems to run it on my PC. It seems as if 128 KB RAM is not enough when you have 100 frames or more. I think that animation shop pro would have worked well on a better PC though and it has many nice features to crop images, add text etc.

4. "mediaconvert" on an SGI finally solved my problem. With this tool I were able to create an avi movie (using compact video, cinepack compression with maximum quality and key-frames every 5th frame). This avi movie plays very well on my laptop in for example windows media player and it can also be included in a powerpoint presentation. The quality is also reasonably good - not quite as good as with "animate" on a workstation, but much better than if you create an mpeg movie. The images I exported from Fluent were of tiff format and had the size 560x400 pixels. I cropped of the 50 pixels at the bottom though - it is better to write your own caption. This size is just on the limit of what my laptop can display without dropping frames. If you have problems with speed/memory you can reduce the size of your exported images.

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Old   January 31, 2000, 17:04
Default Re: Generating High Quality Movies
  #9
Sandeep Abhyankar
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Hello Kai, I did download the trial copy of the "animation" shop , and create an animation from tiff files generated in fluent. The quality is much better, than that which fluent generates if we use the "mpeg" option in the fluent software. One problem I am having here is image sizing, i am seeing my image in one corner of the frame that I am generating, I dont know why?. Any suggestions as to what I might be doing wrong?. I figure its something to do with the original image size . Many thanks
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Old   January 31, 2000, 18:14
Default Re: Generating High Quality Movies
  #10
Kai Kang
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If the images are jumping from frame to frame, it is possible you did not get a consistent sizes of tiff files while doing hardcopy in fluent.

Another possibility in with animationshop, i am pretty sure you can ask it to choose the animation size automatically the same as the first frame of images and the following frames will be scaled/stretched or centered to the size of the first frame (rather than specifying a size). So if all the frames are of the same size, then the animaiton would be fine.

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Old   February 1, 2000, 10:18
Default Re: Generating High Quality Movies
  #11
Chris
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Does anyone have any pointers to software that can produce AVI or QuickTime animations from image files for unix systems? I know of many packages for Windows, as well as mediaconvert on Irix.

Thanks.
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Old   February 3, 2000, 09:11
Default Re: Generating High Quality Movies, Conclusions
  #12
Stefan Ott
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In my experience the best format for CFD-Animations is the FLC-format. It produces much smaller files than avi/mpg and can be played without quality loss on unix workstation and pc. Several utilities for pruducing flcs are freely available from the internet, I use ppm2fli. For playing the flc on a unix workstation you can use xanim, on the pc you can use aaplay (Autodesk Animation Player), both freely available.
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Old   March 6, 2000, 07:04
Default Re: Generating High Quality Movies
  #13
G. Berntsen
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Hi everyone..

I know that FLUENT offers several ways of making videos of transient calculations, IF it is known before the calculations are performed what the video is supposed to show. My problem is that I didn't realize excactly what I wanted to show in my video, until the calculatoins were done. So know I am stuck with 400 data files that I wish to animate.

As far as I know, the FLUENT postprocessor cannot do this in any easy way. However, according to the manuals, the FluentPost (I have version 1.2) program is supposed to be able to do what I want. Unfortunately, FluentPost cannot read native FLUENT5 data files. They have to be converted to the Fieldview format first.

Is it possible to write some sort of batch-job that can convert my FLUENT5 data files to the Fieldview format?

Thanx.
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Old   March 9, 2000, 22:19
Default Movie Solution
  #14
Arthur Valais
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This has been exactly my problem. In the end I devised a (messy) work-around, which is quite involved.

1. Run your simulation. Find out your upper/lower limits. 2. In fluent, create a journal file and run through your actions that you want to take eg. open a data file, view contours, save hardcopy etc. Close it. 3. Open the journal file and substitute generic names for your in and out files. 4. Write a script that reads the all the data file names and substitutes them into a new journal file along with the template file. *Nb* Fluent doesn't pad out the iteration number file name, you will need to that. 5. Read the new journal file into fluent and it should run and output your pictures for you. This can take a while for a lot of files.

Hope this helps.

--->Arthur Valais

Nb. Just about every case is different for me, so the code is always changing.

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Old   March 10, 2000, 06:08
Default Re: Movie Solution
  #15
G. Berntsen
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Thanks...

I'll try your procedure..

I really think Fluent should implement something that would make it easier to post-process transient calculations.

G. Berntsen
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