[FFmpeg-devel] [PATCH 2/2] opt: print ranges in opt_list()

[Stefano Sabatini]

On date Tuesday 2012-12-04 20:46:41 +0100, Michael Niedermayer encoded:
> The formating can and should be improved.
> 
> Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> ---
>  libavutil/opt.c |   42 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 42 insertions(+)
> 
> diff --git a/libavutil/opt.c b/libavutil/opt.c
> index cd26682..7c94cff 100644
> --- a/libavutil/opt.c
> +++ b/libavutil/opt.c
> @@ -37,6 +37,8 @@
>  #include "mathematics.h"
>  #include "samplefmt.h"
>  
> +#include <float.h>
> +
>  #if FF_API_FIND_OPT
>  //FIXME order them and do a bin search
>  const AVOption *av_find_opt(void *v, const char *name, const char *unit, int mask, int flags)
> @@ -728,10 +730,31 @@ int av_opt_flag_is_set(void *obj, const char *field_name, const char *flag_name)
>      return res & flag->default_val.i64;
>  }
>  
> +static void log_value(void *av_log_obj, int level, double d)
> +{
> +    if      (d == INT_MAX) {
> +        av_log(av_log_obj, level, "INT_MAX");
> +    } else if (d == INT_MIN) {
> +        av_log(av_log_obj, level, "INT_MIN");
> +    } else if (d == (double)INT64_MAX) {
> +        av_log(av_log_obj, level, "I64_MAX");
> +    } else if (d == INT64_MIN) {
> +        av_log(av_log_obj, level, "I64_MIN");
> +    } else if (d == FLT_MAX) {
> +        av_log(av_log_obj, level, "FLT_MAX");
> +    } else if (d == FLT_MIN) {
> +        av_log(av_log_obj, level, "FLT_MIN");
> +    } else {
> +        av_log(av_log_obj, level, "%7.2g", d);
> +    }
> +}
> +
>  static void opt_list(void *obj, void *av_log_obj, const char *unit,
>                       int req_flags, int rej_flags)
>  {
>      const AVOption *opt=NULL;
> +    AVOptionRanges *r;
> +    int i;
>  
>      while ((opt = av_opt_next(obj, opt))) {
>          if (!(opt->flags & req_flags) || (opt->flags & rej_flags))
> @@ -798,6 +821,25 @@ static void opt_list(void *obj, void *av_log_obj, const char *unit,
>          av_log(av_log_obj, AV_LOG_INFO, "%c", (opt->flags & AV_OPT_FLAG_AUDIO_PARAM   ) ? 'A' : '.');
>          av_log(av_log_obj, AV_LOG_INFO, "%c", (opt->flags & AV_OPT_FLAG_SUBTITLE_PARAM) ? 'S' : '.');
>  
> +        r = av_opt_query_ranges(obj, opt->name, AV_OPT_SEARCH_FAKE_OBJ);
> +        if(r) {
> +            switch (opt->type) {
> +            case AV_OPT_TYPE_INT:
> +            case AV_OPT_TYPE_INT64:
> +            case AV_OPT_TYPE_DOUBLE:
> +            case AV_OPT_TYPE_FLOAT:
> +            case AV_OPT_TYPE_RATIONAL:
> +                for (i=0; i<r->nb_ranges; i++) {
> +                    log_value(av_log_obj, AV_LOG_INFO, r->range[i]->value_min);
> +                    av_log(av_log_obj, AV_LOG_INFO, "-");
> +                    log_value(av_log_obj, AV_LOG_INFO, r->range[i]->value_max);
> +                    av_log(av_log_obj, AV_LOG_INFO, " ");
> +                }
> +                break;
> +            }
> +            av_opt_freep_ranges(&r);
> +        }

I suggest to print the value range after the help message, something like:
si                <int>   ..F... set stream index (range: [-1, INT_MAX])

note the space between min and max, or people will get confused
(-123--1... WTF??).

Alternatives:
si                <int:[-1, INT_MAX]>   ..F... set stream index

but looks cryptic (and not align-friendly), or something more verbose like:
si                <int>   ..F... set stream index (value ranging from -1 to INT_MAX)

[...]
-- 
FFmpeg = Fundamental Fabulous Minimalistic Problematic Extravagant Governor