[FFmpeg-devel] [PATCH] Remove libavcodec/opt.c:set_all_opt()

Stefano Sabatini stefano.sabatini-lala
Sat Dec 13 23:35:22 CET 2008


On date Saturday 2008-12-13 22:14:03 +0100, Michael Niedermayer encoded:
> On Sun, Dec 07, 2008 at 07:30:44PM +0100, Stefano Sabatini wrote:
> > Hi all,
> > 
> > currently av_set_string2(), if fed with the name of a named constant
> > or flag, will look for all the non-constant options with the same unit
> > and will set their value to the value of the named constant.
> > 
> > This permits for example to do tricks of the kind:
> > 
> > ffmpeg -mv4 foo -> ffmpeg -flags2 +mv4
> > ffmpeg -zero bar -> ffmpeg -me_method zero
> > 
> > The problem with this is that this "feature" isn't reliable, since it
> > only works with the *first* constant found, while different named
> > constants may have the same name, so the user has to know the options
> > array in order to predict the behaviour.
> > 
> > For example without knowing the options order "ffmpeg -auto 1" may mean:
> > 1) ffmpeg -idct auto
> > 2) ffmpeg -dct auto
> > 3) ffmpeg -aa auto
> > 
> > Even worse, something like:
> > ffmpeg -dct 1
> > 
> > may be interpreted both as:
> > ffmpeg -dct 1
> > or
> > ffmpeg -cmp_func dct
> > 
> > (BTW the current code will broke if a named constant is defined
> > *before* a parameter with the same name.)
> > 
> > I propose to remove this feature, this also makes the code smaller and
> > simpler.
> [...]
> > -    if(!o || !val || o->offset<=0)
> > +    if((o && o->offset<=0) || !o || !val)
> 
> huh?

Ops...

Regards.
-- 
FFmpeg = Frenzy & Fiendish Mind-dumbing Puritan Erratic Gorilla
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