diff options
| author | Michael Niedermayer <michaelni@gmx.at> | 2011-10-08 03:09:16 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2011-10-08 03:13:21 +0200 |
| commit | ac7cda9e149918c2d0afc94b82dea02802ed6f90 (patch) | |
| tree | 56c26dfefef83fb0f3e845b9e16d7bde8effb1c0 /libavutil/eval.c | |
| parent | 8fd56f7b121262e3305dfee57737f0ad45b3c6ff (diff) | |
eval: add random()
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Diffstat (limited to 'libavutil/eval.c')
| -rw-r--r-- | libavutil/eval.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/libavutil/eval.c b/libavutil/eval.c index 1ec56946d8..ecb389b57a 100644 --- a/libavutil/eval.c +++ b/libavutil/eval.c @@ -126,7 +126,7 @@ struct AVExpr { 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_floor, e_ceil, e_trunc, - e_sqrt, e_not, + e_sqrt, e_not, e_random, } type; double value; // is sign in other types union { @@ -156,6 +156,13 @@ static double eval_expr(Parser *p, AVExpr *e) case e_trunc: return e->value * trunc(eval_expr(p, e->param[0])); case e_sqrt: return e->value * sqrt (eval_expr(p, e->param[0])); case e_not: return e->value * eval_expr(p, e->param[0]) == 0; + case e_random:{ + int idx= av_clip(eval_expr(p, e->param[0]), 0, VARS-1); + uint64_t r= isnan(p->var[idx]) ? 0 : p->var[idx]; + r= r*1664525+1013904223; + p->var[idx]= r; + return e->value * (r * (1.0/UINT64_MAX)); + } case e_while: { double d = NAN; while (eval_expr(p, e->param[0])) @@ -294,6 +301,7 @@ static int parse_primary(AVExpr **e, Parser *p) else if (strmatch(next, "sqrt" )) d->type = e_sqrt; else if (strmatch(next, "not" )) d->type = e_not; else if (strmatch(next, "pow" )) d->type = e_pow; + else if (strmatch(next, "random")) d->type = e_random; else { for (i=0; p->func1_names && p->func1_names[i]; i++) { if (strmatch(next, p->func1_names[i])) { @@ -463,6 +471,7 @@ static int verify_expr(AVExpr *e) case e_trunc: case e_sqrt: case e_not: + case e_random: return verify_expr(e->param[0]); default: return verify_expr(e->param[0]) && verify_expr(e->param[1]); } |