[GRASS-user] need help with mac os x installation

[Glynn Clements]

Michael Barton wrote:

> > I can't remember who wrote it or where I found it (maybe attached to
> > a list message), but there is a tcl script version - from 2005/11.  I
> > don't see it it either of the addons pages.
> > 
> > Maybe the Python GUI would be a good place for it?
> 
> I'd like to add a native wxPython animation tool, but want to get the
> georectifier built first.
> 
> If we had a good mpeg output, there is a real nice media viewer built into
> wxPython. However, there have been several discussions about mpeg (or other
> media) output that been pretty disheartening. The last time this was
> discussed, I got the impression that most encoders are either proprietary or
> not cross-platform.

The problem with encoding to MPEG (etc) is that it's slow. xganim is
intended for "live" visualisation, so the time between starting xganim
and the animation starting is a key factor.

In that regard, a monolithic process has the advantage of not having
to export the images to files then read them back into memory. Also,
if the display format doesn't exactly match the image format, some
conversion will be necessary on import.

> However, it wouldn't be terribly difficult to more or less do what xganim
> does. The way I've been thinking about it is to have the user specify a
> prefix OR simply list a bunch of maps. These would then be rendered as PNG's
> using r.out.png and then sequentially displayed in a canvas, with some
> control buttons. 

That's essentially what the xganim.tcl script does, except that it
uses PPMs (Tk doesn't understand PNG, only XBM, GIF and PPM).

-- 
Glynn Clements <glynn at gclements.plus.com>