[MPlayer-dev-eng] [PATCH] Pan&Scan for Xvideo (again :)

[Samuel Liddicott]

----- Original Message -----
From: "D Richard Felker III" <dalias at aerifal.cx>
To: <mplayer-dev-eng at mplayerhq.hu>
Sent: Tuesday, June 04, 2002 1:43 PM
Subject: Re: Re: Re: [MPlayer-dev-eng] [PATCH] Pan&Scan for Xvideo (again :)


> Very cool. Building the table of center/extent of action for each
> frame should be pretty easy, but then controlling the panning based on
> that data could be a bit tricky to get looking natural. Perhaps it
> would make sense to also keep track of existing panning in the movie
> (lots of mv's with same direction and length), and when possible, pan
> the viewable region at the same time, so that the result is just an
> increase or decrease in existing panning speed, rather than an
> entirely new pan. Not sure how often this could be exploited, but I
> expect it would help eliminate the look of unnatural
> computer-generated pans when it works.

I think this sounds good.  I'm now talking out of my hat:

Let each point of action take a value based on the ammount of action and
size of action and let this decay over time.
If all points of action can fit in one Screen then let to have the bounding
rect within the shot the goal, otherwise divide the action into clusters
until the biggest cluster bounding rect fits within the screen and make that
the goal.
Then creating a pan, or adjust a current pan, to reach the new goal.

I'm not so hot on how to split action into clusters, maybe you could scan a
screen-sized bounding rect over the entire area and see when it encloses
most action?  But then you might get half of two bits of action on opposite
sides.  Perhaps cutting out action not entirely enclosed by the screen?  But
all action may be to big...

But even unnatural panning is better than missing the action - and of the
action is more rapid there will be less time to notice the quality of the
panning,

Sam