[Cin] Issues related to Motion Plugin

[Georgy Salnikov]

On Sun, 25 Sep 2022, Miroslav Rovis wrote:

> > If the user needs only a smoothed video, perhaps he should not do it with
> > the Motion plugin. The ffmpeg's vid.stab plugin is much easier to use, it is
> > faster, and gives very good results.
> Huh! I'll try and see what that is. But where is it? Search
> 'vid.stab' in ${cin_src_root}/ gives nothing.
> So that must be what you mean.
> But where is it in the GUI? Right click on a video track,

Vid.stab is a ffmpeg plugin linked to it as an external module. Although
this module is maintained separately, it is so useful that it is included
perhaps in all the binary distributions of ffmpeg. As part of the ffmpeg
binary, its filters are used from ffmpeg's command line.

The corresponding vid.stab ffmpeg filters are called vidstabdetect and
vidstabtransform, see ffmpeg's manpages.

Although some ffmpeg's filters can be used inside cinelerra, vidstabdetect
and vidstabtransform cannot. These filters are used as a two steps
procedure: first you call ffmpeg with the vidstabdetect filter and without
any encodings (for speed), the translation displacements will be generated.
Then you call ffmpeg with the vidstabtransform filter followed by encoding
codecs, the produced video will have the displacements applied. Cinelerra
does not support such two-step calls. Therefore, it has also no GUI for this
kind of ffmpeg filters.

So you firstly prepare your shaky video clips with ffmpeg, then load the
stabilized results into cinelerra.

Btw, I would recommend to use cingg's Motion stabilization in the similar
way: adjust Motion parameters, render the corresponding part, then replace
the shaky original with the stabilized result. It is much more convenient.

_______________________________________________________________________________

Georgy Salnikov
NMR Group
Novosibirsk Institute of Organic Chemistry
Lavrentjeva, 9, 630090 Novosibirsk, Russia
Phone   +7-383-3307864
Email   sge at nmr.nioch.nsc.ru
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