[FFmpeg-devel] [PATCH 7/7] Implement isnan() function evaluation.

[Víctor Paesa]

Hi,

On Mon, Nov 1, 2010 at 00:23, Stefano Sabatini wrote:
> ---
> ?doc/eval.texi ? ?| ? ?1 +
> ?libavutil/eval.c | ? ?9 +++++++--
> ?2 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/doc/eval.texi b/doc/eval.texi
> index c944b3e..768525c 100644
> --- a/doc/eval.texi
> +++ b/doc/eval.texi
> @@ -33,6 +33,7 @@ The following functions are available:
> ?@item abs(x)
> ?@item squish(x)
> ?@item gauss(x)
> + at item isnan(x)
> ?@item mod(x, y)
> ?@item max(x, y)
> ?@item min(x, y)
> diff --git a/libavutil/eval.c b/libavutil/eval.c
> index 83e602d..7438ab2 100644
> --- a/libavutil/eval.c
> +++ b/libavutil/eval.c
> @@ -118,7 +118,7 @@ static int strmatch(const char *s, const char *prefix)
> ?struct AVExpr {
> ? ? enum {
> ? ? ? ? e_value, e_const, e_func0, e_func1, e_func2,
> - ? ? ? ?e_squish, e_gauss, e_ld,
> + ? ? ? ?e_squish, e_gauss, e_ld, e_isnan,
> ? ? ? ? e_mod, e_max, e_min, e_eq, e_gt, e_gte,
> ? ? ? ? e_pow, e_mul, e_div, e_add,
> ? ? ? ? e_last, e_st, e_while, e_if,
> @@ -144,6 +144,7 @@ static double eval_expr(Parser *p, AVExpr *e)
> ? ? ? ? case e_squish: return 1/(1+exp(4*eval_expr(p, e->param[0])));
> ? ? ? ? case e_gauss: { double d = eval_expr(p, e->param[0]); return exp(-d*d/2)/sqrt(2*M_PI); }
> ? ? ? ? case e_ld: ? ? return e->value * p->var[av_clip(eval_expr(p, e->param[0]), 0, VARS-1)];
> + ? ? ? ?case e_isnan: ?return e->value * isnan(eval_expr(p, e->param[0]));

I would prefer that eval's isnan returns either 1 or 0.
(The math.h isnan() returns either a non-zero value or 0)

> ? ? ? ? case e_while: {
> ? ? ? ? ? ? double d = NAN;
> ? ? ? ? ? ? while (eval_expr(p, e->param[0]))
> @@ -278,6 +279,7 @@ static int parse_primary(AVExpr **e, Parser *p)
> ? ? else if (strmatch(next, "lte" ? )) { AVExpr *tmp = d->param[1]; d->param[1] = d->param[0]; d->param[0] = tmp; d->type = e_gt; }
> ? ? else if (strmatch(next, "lt" ? ?)) { AVExpr *tmp = d->param[1]; d->param[1] = d->param[0]; d->param[0] = tmp; d->type = e_gte; }
> ? ? else if (strmatch(next, "ld" ? ?)) d->type = e_ld;
> + ? ?else if (strmatch(next, "isnan" )) d->type = e_isnan;
> ? ? else if (strmatch(next, "st" ? ?)) d->type = e_st;
> ? ? else if (strmatch(next, "while" )) d->type = e_while;
> ? ? else if (strmatch(next, "if" ? ?)) d->type = e_if;
> @@ -443,7 +445,8 @@ static int verify_expr(AVExpr *e)
> ? ? ? ? case e_func1:
> ? ? ? ? case e_squish:
> ? ? ? ? case e_ld:
> - ? ? ? ?case e_gauss: return verify_expr(e->param[0]);
> + ? ? ? ?case e_gauss:
> + ? ? ? ?case e_isnan: return verify_expr(e->param[0]);
> ? ? ? ? default: return verify_expr(e->param[0]) && verify_expr(e->param[1]);
> ? ? }
> ?}
> @@ -583,6 +586,8 @@ int main(void)
> ? ? ? ? "st(0, 1); while(lte(ld(0),100), st(1, ld(1)+ld(0));st(0, ld(0)+1))",
> ? ? ? ? "if(1, 123)",
> ? ? ? ? "if(eq(0,1), 123)",
> + ? ? ? ?"isnan(1)",
> + ? ? ? ?"isnan(NAN)",
> ? ? ? ? NULL
> ? ? };

Regards,
V?ctor