[MPlayer-G2-dev] Re: trying mp_image -> get/release_buffer migration...

[D Richard Felker III]

On Thu, May 29, 2003 at 10:25:31AM +0300, Andriy N. Gritsenko wrote:
>     Hi, D Richard Felker III!
> 
> Sometime (on Wednesday, May 28 at 23:17) I've received something...
> >>     Another question is if we will allow mixing video. It will be very
> >> big advantage to have more that one input stream for filter. So I think
> >> while you already will change vf_instance_t then you can add some new
> >> function vf_reopen_filter(). I'll try to describe it. If filter can have
> >> _only_ one input stream then all is as it is now and vf->prev contains
> >> previous vf and vf_reopen_filter() will work exactly as vf_open_filter().
> >> If filter can support more than one input stream then it on open() will
> >> remove vf->prev into internal structure and set vf->prev to NULL. Then
> >> next call of function vf_reopen_filter() will check it and return error
> >> if that pointer is no-NULL. So for filter with only one input stream that
> >> vf_reopen_filter() will call vf->open() only once and for filter with
> >> more streams it may be called as much as filter allows. I hope that
> >> solution is good and fully compatible with all current implementation.
> >> That have also another advantage - it allows as to build concurrent OSD
> >> just as filter module not another layer that will mix video and OSD
> >> inputs. :)
> 
> >That's a slow and nonsensical way to do OSD... Yes, we want
> >multi-input support, but I don't think multiple opens makes any sense.
> >If anything, multiple config, once for each source, but open should be
> >called only once.
> 
>     I've proposed it to avoid changes as much as possible. Another way
> will bring changes in vf_instance_t structure. Beside of that, even multi
> vf->open() call are good if it's documented well. Don't forget that some
> GUI may want add input stream in already created chain (so vf->open() was
> already called) instead of saving parameters, destroying all chain and
> recreating it with new source for that filter.
>     Anyway, if you have another solution - please, give it to us here. :)

I think you misunderstand the open call. open is not used to connect
an input to the filter, just to initialize the instance. config is the
call that connects an input.

Rich