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eval: add support for trunc, ceil, and floor functions

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Signed-off-by: Stefano Sabatini <stefano.sabatini-lala@poste.it>
Signed-off-by: Anton Khirnov <anton@khirnov.net>
This commit is contained in:
Stefano Sabatini 2011-04-09 13:49:54 +02:00 committed by Anton Khirnov
parent 2fd8756b9f
commit 5ae4251c3b
3 changed files with 32 additions and 3 deletions
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12
doc/eval.texi
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@ -60,6 +60,18 @@ The function returns the loaded value.
Evaluate expression @var{expr} while the expression @var{cond} is
non-zero, and returns the value of the last @var{expr} evaluation, or
NAN if @var{cond} was always false.
@item ceil(expr)
Round the value of expression @var{expr} upwards to the nearest
integer. For example, "ceil(1.5)" is "2.0".
@item floor(expr)
Round the value of expression @var{expr} downwards to the nearest
integer. For example, "floor(-1.5)" is "-2.0".
@item trunc(expr)
Round the value of expression @var{expr} towards zero to the nearest
integer. For example, "trunc(-1.5)" is "-1.0".
@end table
Note that:

2
libavutil/avutil.h
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@ -41,7 +41,7 @@
#define LIBAVUTIL_VERSION_MAJOR 50
#define LIBAVUTIL_VERSION_MINOR 40
#define LIBAVUTIL_VERSION_MICRO 0
#define LIBAVUTIL_VERSION_MICRO 1
#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
LIBAVUTIL_VERSION_MINOR, \

21
libavutil/eval.c
View File

@ -121,7 +121,7 @@ struct AVExpr {
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_last, e_st, e_while, e_floor, e_ceil, e_trunc,
} type;
double value; // is sign in other types
union {
@ -145,6 +145,9 @@ static double eval_expr(Parser *p, AVExpr *e)
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]));
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_trunc: return e->value * trunc(eval_expr(p, e->param[0]));
case e_while: {
double d = NAN;
while (eval_expr(p, e->param[0]))
@ -276,6 +279,9 @@ static int parse_primary(AVExpr **e, Parser *p)
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, "floor" )) d->type = e_floor;
else if (strmatch(next, "ceil" )) d->type = e_ceil;
else if (strmatch(next, "trunc" )) d->type = e_trunc;
else {
for (i=0; p->func1_names && p->func1_names[i]; i++) {
if (strmatch(next, p->func1_names[i])) {
@ -439,7 +445,11 @@ static int verify_expr(AVExpr *e)
case e_squish:
case e_ld:
case e_gauss:
case e_isnan: return verify_expr(e->param[0]);
case e_isnan:
case e_floor:
case e_ceil:
case e_trunc:
return verify_expr(e->param[0]);
default: return verify_expr(e->param[0]) && verify_expr(e->param[1]);
}
}
@ -611,6 +621,13 @@ int main(void)
"st(0, 1); while(lte(ld(0),100), st(1, ld(1)+ld(0)); st(0, ld(0)+1))",
"isnan(1)",
"isnan(NAN)",
"floor(NAN)",
"floor(123.123)",
"floor(-123.123)",
"trunc(123.123)",
"trunc(-123.123)",
"ceil(123.123)",
"ceil(-123.123)",
NULL
};