[MPlayer-dev-eng] Re: [PATCH] VFCTRL_PERIODIC_UPDATE

[Diego Biurrun]

On Mon, Jan 22, 2007 at 03:14:23PM -0500, Jason Tackaberry wrote:
> On Mon, 2007-01-22 at 21:25 +0200, Uoti Urpala wrote:
> > A vo extension to allow editing the currently visible frame, implemented
> > at least for xv, might be the most practical way.
> 
> The way I did this for xine was to create a special vo driver that
> blended the overlay before handing off the frame to the real vo driver.
> The reason I did it this way was because xine has no notion of
> unbuffered post plugins, so if implemented as a post plugin (i.e. vf) it
> would be several (up to 10 or so) frames behind. 
> 
> Perhaps this approach may also work here, and has the added benefit of
> being vo-agnostic.  So we have a special overlay vo that passes through
> to the real vo driver after blending the overlay.  And if the overlay is
> off, it will use DR and/or slices if possible (supported by the target
> vo).  So something like -vo
> overlay:shmkey=12345678:passthrough=xv:port=79

Check out vo_xover.  IIRC it does something similar.

Diego