[vtkusers] How to write AVI files properly, Please Help

[Beau Sapach]

I think I had a similar problem, not the size issue but the single, static
image issue.  Try calling Modified() on vtkWindowToImageFilter before you
call Update().  As for frame rate I don't know how to set that with vtk's
classes, I suggest you look at FFMPEG, it can be built into VTK but I've had
little luck doing so.  Currently I write out image files and have my
application call the ffmpeg executable to encode the images as a movie,
using ffmpeg command line options you can control framerate.

 

Beau

 

  _____  

From: vtkusers-bounces+beau.sapach=ualberta.ca at vtk.org
[mailto:vtkusers-bounces+beau.sapach=ualberta.ca at vtk.org] On Behalf Of Janny
Dong
Sent: Tuesday, May 29, 2007 8:24 AM
To: vtkusers
Subject: [vtkusers] How to write AVI files properly, Please Help

 

I posted a similar question but didn't get any answer, probably I didn't
make it clear enough.

I am coding a C++ program to visualize my data and generate movie
automatically. I put vtkAVIWriter in a loop to get a movie out of the
rendering. It did get an avi file, but not the one I expected. I have two
questions about it. 

(1) The size of the movie file is 18MB, but it has only 50 frames. Moreover,
it is only 3 second long. Can I compress the movie file with vtkAVIWriter?
How can I control the speed of the movie, like specifying number of frames
per second? 

(2) I found the avi file displayed only one frame like a static image.
However, I did update the data when rendering each frame. The data rendering
part in my program is like
data
points--->vtkPolyData--->vtkDelaunay2D--->vktPolyDataMapper--->vtkRenderer--
->vtkWin32OpenGLRenderWindow->SetOffScreenRendering(1)--->vtkWindowToImageFi
lter--->vtkAVIWriter 

I have something like: PolyDataMapper->update(); WindowToImage->update() in
my code.  Did I call update() in a wrong way or should I call it in
different parts of the code?

Any suggestions will be greatly appreciated. 

Janny
 

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