[Kdenlive-devel] GPU effects?

[Dan Dennedy]

On Fri, Dec 12, 2008 at 7:31 AM, Collin Kidder <adderd at kkmfg.com> wrote:
> Hello, I'm brand new to both KDEnlive and this list. So, I figured I'd
> start out with really tough stuff first...
>
> What are the odds of getting GPU based effects? Specifically I'd like to

I am pessimistic about the odds, but the odds don't really matter.
Let's just say, it is not on the near-to-midterm roadmap for any
Kdenlive/MLT developers as far as I know. (I am the MLT lead
developer.)

> have hardward motion comp and deinterlacing. Adobe Premiere on windows

motion compensation for what - decoding? If so, I refer you to FFmpeg.
They are currently trying to integrate VDPAU patches from NVIDIA. That
might take a while:
http://http.download.nvidia.com/XFree86/vdpau/doxygen/html/index.html

It might be nice to have something more generic, but at least Roman
Shaposhnik, the FFmpeg DV developer is working on a more generic,
comprehensive multi-threading capability in ffmpeg/libavcodec.

> can do this. It really makes DV video look a lot better. Eventually
> other shader type effects would be nice. I do intend on looking into
> this myself but to start me off let me ask this: Should this be done
> through an existing framework such as MLT? I think that a range of the
> current effects could be done on the GPU. Sepia, black and white,

Kdenlive's video filters and transitions come from MLT and MLT's
bridge to the frei0r plugins. There is a project called FreeFrame that
is a plugin interface and set of plugins, some of which are
OpenGL-accelerated. It seems more suited towards VJ apps, but maybe it
will work here. In that case, use the MLT frei0r module as inspiration
for a bridge component to these FreeFrame.

> I tried to search this list for prior discussions on this subject. I did
> not find much of anything. Is no one interested in GPU acceleration?

Definitely interested, but I you know the expression: "you gotta walk
before you can run." I am currently addressing bugs and fundamental
issues with the framework at the moment instead of the modules. Some
of the changes underway are to make it easier to integrate alternative
implementations of image scalers, deinterlacers, colorspace, and
sample format converters that would facilitate your interests. It can
be be done today, but not so cleanly.

> To be clear, I'm not really asking someone else to do it. I'll try
> myself. But any pointers toward where to look, what should be possible,
> etc would be appreciated.

Sounds great; go for it!

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