[FFmpeg-devel] [PATCH] Remove libavcodec/opt.c:set_all_opt()
Stefano Sabatini
stefano.sabatini-lala
Sat Dec 13 00:04:27 CET 2008
On date Sunday 2008-12-07 19:30:44 +0100, Stefano Sabatini encoded:
> 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.
>
> Regards.
[...]
> Index: libavcodec/opt.c
> ===================================================================
> --- libavcodec/opt.c (revision 16030)
> +++ libavcodec/opt.c (working copy)
> @@ -76,24 +76,6 @@
> return o;
> }
>
> -static const AVOption *set_all_opt(void *v, const char *unit, double d){
> - AVClass *c= *(AVClass**)v; //FIXME silly way of storing AVClass
> - const AVOption *o= c->option;
> - const AVOption *ret=NULL;
> -
> - for(;o && o->name; o++){
> - if(o->type != FF_OPT_TYPE_CONST && o->unit && !strcmp(o->unit, unit)){
> - double tmp= d;
> - if(o->type == FF_OPT_TYPE_FLAGS)
> - tmp= av_get_int(v, o->name, NULL) | (int64_t)d;
> -
> - av_set_number(v, o->name, tmp, 1, 1);
> - ret= o;
> - }
> - }
> - return ret;
> -}
> -
> static const double const_values[]={
> M_PI,
> M_E,
> @@ -117,10 +99,7 @@
>
> const AVOption *av_set_string2(void *obj, const char *name, const char *val, int alloc){
> const AVOption *o= av_find_opt(obj, name, NULL, 0, 0);
> - if(o && o->offset==0 && o->type == FF_OPT_TYPE_CONST && o->unit){
> - return set_all_opt(obj, o->unit, o->default_val);
> - }
> - if(!o || !val || o->offset<=0)
> + if((o && o->offset<=0) || !o || !val)
> return NULL;
> if(o->type == FF_OPT_TYPE_BINARY){
> uint8_t **dst = (uint8_t **)(((uint8_t*)obj) + o->offset);
Ping.
Regards.
--
FFmpeg = Faboulous and Fostering Minimalistic Powerful Ecumenical Gadget
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