Smooth video retiming

[Olivier Girard]

Smooth slow motion compositing should be available using optical flow. This should be done with curves that allow arbitrary time accelereation/deceleration/reversal rather than a constant factor.

For gstreamer apps, this means supporting the gstreamer optical flow plugin. The optical flow plugin should also get on par with V3D (part of the nvidia cg toolkit http://developer.nvidia.com/cg-toolkit-download), which is used for slowmoVideo: http://slowmovideo.granjow.net/

Depending this article in French (http://linuxfr.org/users/dtschump/journaux/retiming-vid%C3%A9o-et-logiciels-libres), there is two solutions either remove some frames (you loose in quality) either you keep the number of frames initial, add some intermediate frames, which one interpole the movement and the pixels.

Quickly, I will develop in another bug. This algorithm is a part of the impressive awesome G'mic () which one is a framework, a library and a script language(at the level of Mathmap, Imagemagick) Easy to install because he is in the repository, You have two examples in EKD and the plugin G'mic for The Gimp. And that 's just a few part of his potential (more than 500 commands available (or 1000 , I don't remember exactly the number !!!) . This algorithm done a clean work.
Two sample are better that 1000 words.
The original video : http://video.google.com/videoplay?docid=-2836117890993338671&hl=en%22#
The video with the algorithm : http://video.google.com/videoplay?docid=2486178536262832270&hl=en#
Thanks.

[Jeff Fortin Tam (kiddo)]

Somehow, nobody told me about this bug report :) anyway, this has been in the pitivi roadmap for a long time. See:

http://jeff.ecchi.ca/blog/2009/07/15/variable-time-stretching-ramping/
https://bugzilla.gnome.org/show_bug.cgi?id=593828
http://wiki.pitivi.org/wiki/Roadmap
http://wiki.pitivi.org/wiki/PiTiVi_Love

And so on. Patches welcome. Hint: finishing the integration of David Jordan's optical flow plugin for gstreamer and then adding it to GES and Pitivi with a nice user interface won't be trivial.