[FFmpeg-devel] [PATCH] avutil/opt: Support max > INT64_MAX in write_number() with AV_OPT_TYPE_INT64

[wm4]

On Sun, 25 Oct 2015 19:46:42 +0100
Michael Niedermayer <michaelni at gmx.at> wrote:

> From: Michael Niedermayer <michael at niedermayer.cc>
> 
> This allows for example to set max to UINT64_MAX and set values in that
> range
> 
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>  libavutil/opt.c |   12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/libavutil/opt.c b/libavutil/opt.c
> index 36eeeb0..157179c 100644
> --- a/libavutil/opt.c
> +++ b/libavutil/opt.c
> @@ -102,7 +102,17 @@ static int write_number(void *obj, const AVOption *o, void *dst, double num, int
>      case AV_OPT_TYPE_INT:   *(int       *)dst= llrint(num/den)*intnum; break;
>      case AV_OPT_TYPE_DURATION:
>      case AV_OPT_TYPE_CHANNEL_LAYOUT:
> -    case AV_OPT_TYPE_INT64: *(int64_t   *)dst= llrint(num/den)*intnum; break;
> +    case AV_OPT_TYPE_INT64:
> +        // We must special case uint64_t here as llrint() does not support values
> +        // outside the int64_t range and there is no portable function which does
> +        // "INT64_MAX + 1ULL" is used as it is representable exactly as IEEE double
> +        // while INT64_MAX is not
> +        if (o->max > INT64_MAX + 1ULL && num/den > INT64_MAX + 1ULL) {
> +            *(uint64_t *)dst = (llrint(num/den - (INT64_MAX + 1ULL)) + (INT64_MAX + 1ULL))*intnum;
> +        } else {
> +            *(int64_t  *)dst = llrint(num/den)*intnum;
> +        }
> +        break;
>      case AV_OPT_TYPE_FLOAT: *(float     *)dst= num*intnum/den;         break;
>      case AV_OPT_TYPE_DOUBLE:*(double    *)dst= num*intnum/den;         break;
>      case AV_OPT_TYPE_RATIONAL:

Introducing AV_OPT_TYPE_UINT64 would be cleaner...