[FFmpeg-devel] [PATCH] Implement libavcodec/opt.[ch] generic options handling

[Michael Niedermayer]

On Thu, Jan 08, 2009 at 01:51:11AM +0100, Stefano Sabatini wrote:
> On date Monday 2009-01-05 19:52:58 +0100, Michael Niedermayer encoded:
> > On Mon, Jan 05, 2009 at 02:04:11PM +0100, Stefano Sabatini wrote:
> > > Hi all,
> > > 
> > > this is my first attempt to move the option handling code from the
> > > applications to the library, it also should make possible to remove
> > > the deprecated lavf AVFormatParameters.
> > > 
> > > Please comment.
> > > 
> > > Regards.
> > > -- 
> > > FFmpeg = Furious Faboulous Majestic Picky Encoding/decoding Gangster
> > 
> > > Index: ffmpeg/libavcodec/opt.c
> > > ===================================================================
> > > --- ffmpeg.orig/libavcodec/opt.c	2009-01-05 13:49:31.000000000 +0100
> > > +++ ffmpeg/libavcodec/opt.c	2009-01-05 13:51:55.000000000 +0100
> > > @@ -114,7 +114,7 @@
> > >          *o_out = o;
> > >      if(!o)
> > >          return AVERROR(ENOENT);
> > > -    if(!val || o->offset<=0)
> > > +    if(!val || (o->type != FF_OPT_TYPE_HANDLER && o->offset<=0))
> > >          return AVERROR(EINVAL);
> > >  
> > >      if(o->type == FF_OPT_TYPE_BINARY){
> > 
> > this patch needs a seperate thread and some justification why it would be
> > a good idea
> > [...]
> 
> Well, why would this be useful?
> 
> This would make possible for example to use the frame size/rate
> abbreviation using av_set_string3(), when it is currently possible
> only in the ff* tools while, having this facility in the library will
> avoid to duplicate the code.
> 
> It also may be used for moving other code (e.g.: opt_preset() and
> opt_target()) from applications to the library, reducing overall code
> duplication and providing an higher level API.
> 
> > and moving the AVOption related code from libav*/utils to libav*/options is
> > fine if that is really just moving and done with svn cp
> 
> Done in a separate thread.

what is the advantage of OPT_TYPE_HANDLER over adding 
OPT_TYPE_BLAH FOO and BAR ?

similarly what is the advantage of not handling all by OPT_TYPE_HANDLER
and not have any other types ?

supporting such a 2 layer system means more complexity than a single
layer whichever of the 2 that would be


[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I have often repented speaking, but never of holding my tongue.
-- Xenocrates
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