[Kdenlive-devel] My experience with Blender

[Giuseppe Ghibò]

Gerhard Hübner wrote:

> After I found out that Blender has a dedicated video sequence editor, I
> thought it is worth the effort to try making animatesd slide shows with
> it.
> 
> The good news: it works, sort of, the GUI is not that bad. It is
> possible to load pictures, stretch them to the desired sequence length,
> insert per-picture and picture-to-picture transition effects, including
> the one that is known elswhere as "Ken Burns", i.e. zooming and panning
> in the picture...
> 
> The bad news: Blender downsamples every imported image to the selected
> video resolution. When I zoom into an image using the transform effect,
> Blender does NOT used the original image quality but just inflates the
> pixels of the previously downsampled image!!! This ruins the whole
> function and makes it practically useless. My big multi-megapixel-images
> just get squeezed to nothing and then inflated into an ugly pixelated
> mess. 

AFAIK this doesn't happens in blender, i.e. it doesn't downsample.
You have problably set the render resolution to a low value. Furthermore
if you have a low res image and you set resolution to HD, it can even do upsampling.

Regarding the two other program you cited (cinelerra & jahshaka), I was too seeking for
a tool capable of doing HD compositing, but more or less I get
the same problems. E.g. under jahshaka (which is available in
mandriva distro in contrib), I found it's still a bit unstable,
and cvs seems not updated by long time. There I also got
crashes due to this bug: http://qa.mandriva.com/show_bug.cgi?id=32163

Regarding cinelerra, I tried it (up to version cvs1046 which is
latest), but in HD video (trying the cinelerra HD samples at the cvs.cinelerra.org
site, or the HD videos available at http://www.apple.com/trailers) I found substantially
two problems: despite it claims
it can do HD smootly, I found that on a Dual Core Athlon64
4800 it doesn't have enough power even to do a HD playback
on the compositor window. And often while clicking or moving on the playback
slider in the compositor window it just hangs (just hangs not crashes). Ditto also
on dual Dual-Opteron 2218 with 8GB of memory and a RAID0 hw system. The same HD
video playing in mplayer doesn't consumes more than 35% of CPU usage
on the same hardware. Even doing some oprofiling didn't show any
particular bottenleck. I wonder if other people have had some positive
experience in HD compositing.

> 
> How sad, 10 hours of work wasted just because someone who coded this
> function didn't understand the basic mathematics of scaling, viewports
> and linear transformations...
> 
> So I ended up discarding yet another tool that looked nice at first but
> failed due to some very simple things not correctly implemented. On the
> list of failures are also:
> - Jahshaka (spent several days to get it working, no hope)
> - Cinelerra: Editing simply doesn't work, crashes and hangs frequently,
> looks abandoned.
> - Kino: solution looking for a problem
> - Slcreator: nice idea to provide GUI frontend to DVD-Slideshow, but
> loves crashing and wasting memory and is written in some Visual Basic
> derivative that no one else wants to develop with... why didn't that guy
> use python, perl or TCL?
>