[MPlayer-users] Stabilizer filter in MEncoder?

[ivanova]

On Thu, 2 Sep 2004 10:34:06 -0400
D Richard Felker III <dalias at aerifal.cx> wrote:

> On Thu, Sep 02, 2004 at 12:40:29AM -0500, Stephen Stocker wrote:
> > >>   Hi,
> > >>
> > >>   I'm wondering if there's a filter in MEncoder which could be used as a
> > >>   stabilizer in some way? What I'm looking for is something which can
> > >>   stabilize old home movies, to lessen the jerkiness caused by the
> > >>   movements of the cameraman.
> > >>
> > >>   If this isn't possible, does anyone know of a command-line utility or
> > >>   something of that nature for Linux which will do this? Thanks.
> > >>
> > >>   Steve
> > >
> > >there's no such feature right now, and actually it's a very difficult
> > >task, stabilizing video. it would be a cool filter for someone to
> > >write eventually, but don't expect to see it soon.
> > >
> > >rich
> > 
> >   Thanks Rich. Yeah, it would be nice, but I got the impression from
> >   searching for such a thing that it wasn't an easy thing to do.
> > 
> >   I know almost nothing about the technology involved. For that matter,
> >   I know very little about video in general. :)
> 
> i think the basic idea would be to buffer several frames ahead and do
> motion estimation on them all, then throw out small, 'localized'
> motion that doesn't match the overall motion direction of the frame,
> and finally analyze the global motion of several consecutive frames to
> decide whether it's jerking (back-and-forth) or actual panning
> (consistent motion in one direction). then you have to shift the
> jerked frames to compensate, and finally crop all the frames a little
> bit to make up for the fact that you're missing pixels at the edges of
> compensated frames.
> 
> the hard steps are distinguishing between local&global motion (a
> person moving in the frame vs the camera panning), and between
> jerking&panning (requires analyzing several frames as a group rather
> than each one individually).

I don't really know if this is relevant at all, because I have no idea what the
filter does, (haven't tried it) but I see that avidemux2 has a stabilize filter.
Maybe it does what you want. ;)