[MPlayer-dev-eng] mp-g2 pre14

Arpi arpi at thot.banki.hu
Mon Apr 21 22:23:27 CEST 2003


Hi,

> > Which will be called next, vd can also prepend filters before the first.
> > 
> > I don't see, why this won't be possible...
> 
> Because this does not accomplish the goal at all. It assumes input and
> output frames are in one-to-one correspondence, and it probably
> wouldn't work at all with dr/slices.

yes, but i've mixed the 2 ideas. what about this code:


mp_image_t* vf_process_image(vf_start){
    vf_dunno_t* vf=vf_start;
    mp_image_t* mpi=NULL;

    // find which filter will produce the image for us:
    // (normally this loop goes up to vf_vd, ie to the codec,
    // except if any of the filters above us have pending queued images)
    while((vf=vf->prev)){
	if(vf->process_image)
	    if((mpi=vf->process_image(vf,NULL))) break;
    }
    if(!mpi || !vf) return NULL; // error (codec failed?)
    
    // now vf points to the top filter which produced an image: mpi, and
    // vf_start points to the bottom filter, where we requested the image

    // drive our 'mpi' through the filters from vf to vf_start, including
    // the newcomers (auto-inserted filters)
    while((vf=vf->next) && vf!=vf_start){
	if(vf->process_image)
	    if(!(mpi=vf->process_image(vf,mpi))) // filter image
		return NULL; // some filter inbetween failed :(((((
    }

    // done.    
    return mpi;
}

example filter:

static mp_image_t* process_image(vf_dunno_t* vf, mp_image_t* mpi){
    mp_image_t* dmpi;
    if(!mpi){
	if(we have pending images?){
	    dmpi=vf_get_image(...)
	    render
	    return dmpi;
	}
	return NULL; // no thanks
    }
    dmpi=vf_get_image(...)
    filter mpi into dmpi
    while(we need one more image?){
	mpi=vf_process_image(vf);
	if(!mpi) sorry, no more...
	filter mpi into dmpi
    }
    return dmpi;
}

it should work (in theory, point me posisble problems please).
it allows any filter to insert new filters bellow itself while in
process_image(), and the new filters will be immediately used as soon
as it returns with mpi;


A'rpi / Astral & ESP-team

--
Developer of MPlayer, the Movie Player for Linux - http://www.MPlayerHQ.hu



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