[MPlayer-users] Frame interpolation

[Reimar Döffinger]

On Sat, Jan 02, 2010 at 01:27:00PM -0800, Grant wrote:
> >> > Are there any plans for mplayer to do frame interpolation to negate
> >> > 24p judder?
> >>
> >> There was a time when everyone wanted 24p cameras to look more like "the
> >> movies".
> >>
> >> By which I mean to say: you want to interpolate back up to a higher frame
> >> rate? Blech, what a horrible idea. You might as well go ahead and watch it
> >> in 4:3 crop with mono audio, in black and white, while you're at it, just to
> >> ensure the experience is as damaged as possible.
> >
> > Well, people's opinions and tastes differ...
> > However I guess that many of the multimedia developers would find the
> > artefacts too horrible to actually want that feature, so it is quite
> > unlikely to happen.
> 
> Which artefacts are guaranteed with frame interpolation?  They can't
> be eliminated?

Since it is simply impossible to know what happened in-between those frames
that you have _some_ kind of artefact is unavoidable.
However a human could in principle do a really good interpolation that is
not obvious to recognize as such.
A computer first would have to be able to recognize objects, then use that
information to analyze how they are moving an where their borders are and
then it still must make up the parts that are not visible in either frame
(imagine a fast-spinning cube, one frame shows the "front" side, the next one
the opposite side, how are you going to make the interpolated frame show
the left or right side? There's no way you could know what was on them.).
With the current state of the art I think it usually means that when something
is moving the interpolated frame will be something between blurry or a
slightly strange mesh-up between the two frame - due to the movement it thankfully
will not be (easily) visible to most.
However given that I have nowadays the bad luck of being able to see interlacing
artefacts with analog TVs I personally wouldn't even try to implement it because
it's just too likely I wouldn't be able to enjoy it (and also being used to PAL and
dubbed content I don't really have any issue with 24 fps content anyway).