[GRASS-dev] Re: Nviz animation wish

[William Kyngesburye]

On Jan 25, 2007, at 8:19 AM, Helena Mitasova wrote:

> Michael - there is a file sequencing tool for that in nviz - I have  
> been doing it for years (I also
> had some of it at your workshop), just check my website.
> My slides for the lausanne workshop should have a description how  
> to do it along
> with a sample data set. I need to run now but I can write you more  
> later.
> It may be broken in the latest CVS but it worked well in 6.1
>
I was going to mention this also.  It looks like it can make a series  
of ppm images, or an mpeg if GRASS was built with ffmpeg support.

And this is where I have issues.  I've been wrestling with this for a  
while, trying to get a usable ffmpeg library on Mac OS X.  Because of  
the VERY unstable nature of the ffmpeg project (a perpetual beta),  
it's hard to get something that works at any given time.  This  
probably applies to more than just OSX.  Building a universal binary  
is more difficult because of different processor optimizations.   
Nobody makes binaries for the ffmpeg libraries, just the program.  At  
least on OSX, and I don't want to resort to Fink or Darwinports.

As an alternative to directly in nviz, there is the r.out.mpeg  
module.  You could create the ppms in nviz, then run those thru  
r.out.mpeg.

But that has a similar problem - no Mac binaries for the mpeg-encode  
program that it uses.  And ancient code - I haven't tried building it  
yet, but I expect problems.

A possibility would be to rewrite the r.out.mpeg module to use the  
ffmpeg program or other mpeg encoder, which has readily available  
binaries.  Or just run them manually thru ffmpeg.


A question about the ffmpeg support - is it limited to just the  
mpeg-1 output, or can it use any format supported by ffmpeg?

-----
William Kyngesburye <kyngchaos at kyngchaos.com>
http://www.kyngchaos.com/

First Pogril: Why is life like sticking your head in a bucket filled  
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Second Pogril: I don't know.  Why IS life like sticking your head in  
a bucket filled with hyena offal?
First Pogril: I don't know either.  Wretched, isn't it?

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