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eval: add sqrt function for computing the square root

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This commit is contained in:
Stefano Sabatini 2011-05-03 23:31:14 +02:00 committed by Anton Khirnov
parent 3e033da847
commit 9bc393908a
4 changed files with 17 additions and 1 deletions
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4
doc/eval.texi
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@ -72,6 +72,10 @@ integer. For example, "floor(-1.5)" is "-2.0".
@item trunc(expr) @item trunc(expr)
Round the value of expression @var{expr} towards zero to the nearest Round the value of expression @var{expr} towards zero to the nearest
integer. For example, "trunc(-1.5)" is "-1.0". integer. For example, "trunc(-1.5)" is "-1.0".
@item sqrt(expr)
Compute the square root of @var{expr}. This is equivalent to
"(@var{expr})^.5".
@end table @end table
Note that: Note that:

2
libavutil/avutil.h
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@ -41,7 +41,7 @@
#define LIBAVUTIL_VERSION_MAJOR 51 #define LIBAVUTIL_VERSION_MAJOR 51
#define LIBAVUTIL_VERSION_MINOR 10 #define LIBAVUTIL_VERSION_MINOR 10
#define LIBAVUTIL_VERSION_MICRO 0 #define LIBAVUTIL_VERSION_MICRO 1
#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \ #define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
LIBAVUTIL_VERSION_MINOR, \ LIBAVUTIL_VERSION_MINOR, \

6
libavutil/eval.c
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@ -123,6 +123,7 @@ struct AVExpr {
e_mod, e_max, e_min, e_eq, e_gt, e_gte, e_mod, e_max, e_min, e_eq, e_gt, e_gte,
e_pow, e_mul, e_div, e_add, e_pow, e_mul, e_div, e_add,
e_last, e_st, e_while, e_floor, e_ceil, e_trunc, e_last, e_st, e_while, e_floor, e_ceil, e_trunc,
e_sqrt,
} type; } type;
double value; // is sign in other types double value; // is sign in other types
union { union {
@ -149,6 +150,7 @@ static double eval_expr(Parser *p, AVExpr *e)
case e_floor: return e->value * floor(eval_expr(p, e->param[0])); case e_floor: return e->value * floor(eval_expr(p, e->param[0]));
case e_ceil : return e->value * ceil (eval_expr(p, e->param[0])); case e_ceil : return e->value * ceil (eval_expr(p, e->param[0]));
case e_trunc: return e->value * trunc(eval_expr(p, e->param[0])); 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_while: { case e_while: {
double d = NAN; double d = NAN;
while (eval_expr(p, e->param[0])) while (eval_expr(p, e->param[0]))
@ -283,6 +285,7 @@ static int parse_primary(AVExpr **e, Parser *p)
else if (strmatch(next, "floor" )) d->type = e_floor; else if (strmatch(next, "floor" )) d->type = e_floor;
else if (strmatch(next, "ceil" )) d->type = e_ceil; else if (strmatch(next, "ceil" )) d->type = e_ceil;
else if (strmatch(next, "trunc" )) d->type = e_trunc; else if (strmatch(next, "trunc" )) d->type = e_trunc;
else if (strmatch(next, "sqrt" )) d->type = e_sqrt;
else { else {
for (i=0; p->func1_names && p->func1_names[i]; i++) { for (i=0; p->func1_names && p->func1_names[i]; i++) {
if (strmatch(next, p->func1_names[i])) { if (strmatch(next, p->func1_names[i])) {
@ -450,6 +453,7 @@ static int verify_expr(AVExpr *e)
case e_floor: case e_floor:
case e_ceil: case e_ceil:
case e_trunc: case e_trunc:
case e_sqrt:
return verify_expr(e->param[0]); return verify_expr(e->param[0]);
default: return verify_expr(e->param[0]) && verify_expr(e->param[1]); default: return verify_expr(e->param[0]) && verify_expr(e->param[1]);
} }
@ -600,6 +604,8 @@ int main(int argc, char **argv)
"trunc(-123.123)", "trunc(-123.123)",
"ceil(123.123)", "ceil(123.123)",
"ceil(-123.123)", "ceil(-123.123)",
"sqrt(1764)",
"sqrt(-1)",
NULL NULL
}; };

6
tests/ref/fate/eval
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@ -133,5 +133,11 @@ Evaluating 'ceil(123.123)'
Evaluating 'ceil(-123.123)' Evaluating 'ceil(-123.123)'
'ceil(-123.123)' -> -123.000000 'ceil(-123.123)' -> -123.000000
Evaluating 'sqrt(1764)'
'sqrt(1764)' -> 42.000000
Evaluating 'sqrt(-1)'
'sqrt(-1)' -> -nan
12.700000 == 12.7 12.700000 == 12.7
0.931323 == 0.931322575 0.931323 == 0.931322575