[MPlayer-dev-eng] Dynamic filters

[attila]

On Mon, Apr 19, 2004 at 05:09:41PM -0500, Joey Parrish wrote:
> On Mon, Apr 19, 2004 at 04:28:53PM -0400, Jason Tackaberry wrote:
> > I'm working on a project that uses mplayer in slave mode and I require
> > the ability to manipulate the filter chain dynamically.  Near as I can
> > tell, this isn't currently possible with MPlayer, so I'm looking at
> > coding this functionality myself.
> 
> I am not a filter expert at all.
> IIUC, MPlayer can't add new filters while a video is playing.
> I believe this is a deep architecture issue.

It goes even deeper. Adding filters means in a lot of
cases also changing image format (color space, size,...)
or in capabilities (dr). Thus you need to reinitialize the
whole filter chain if you change anything, which includes
also the removing of automaticaly added conversion filters
(sws) and reinit of the output module.

IIRC even Richs vp requires a full reinit sequence when
changing the filter chain.

> Has anyone considered (for any given project) modifying the filters that
> you need such that their parameters can be changed after the movie
> begins?  Or is this already possible?

Not possible, same reasons as above.

> My idea is that you could insert filters at start, but then turn them
> on and off, giving the effect of dynamic insertion.  (At speed cost.)

This is a bad idea. You cannot add all filters in every
possible order anyways unless you make the chain infinilty long.


			Attila "always a little bit late" Kinali