[MPlayer-users] zooming and moving image

[Reimar Döffinger]

On Sun, Jan 25, 2015 at 06:49:17PM +0400, Anton Sviridenko wrote:
> Hello
> 
> I use mplayer in slave mode for displaying video in application
> through -wid option.
> I need to have zoom in/zoom out and move left/right/up/down feature
> during playback and pause. I looked how it is implemented in SMPlayer,
> and as I understand, the whole widget were video is rendered onto
> (that one whose window id is passed to mplayer) is resized and moved.
> So when only some small part of video is displayed in smplayer window,
> whole picture is still painted by mplayer on other, invisible parts of
> widget. Zooming and moving picture is slow and is not smooth,
> performance is poor.

There is no reason at all for that to be slow, non-smooth or have
performance. At least not any slower than normal video playback.

> Is there some more effective way for displaying only scaled parts of
> video? Maybe it is possible to implement it using filters?

You could use -vf crop, but I don't think it is runtime-controllable.
There is the -panscan* stuff, however it will only zoom to the center
currently.
There is -geometry, but it is not interactive currently.