avutil/eval: Add av_expr_count_func() similar to av_expr_count_vars()

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
pull/331/head
Michael Niedermayer 5 years ago
parent 26f040bcb4
commit 45259a0ee4
  1. 3
      doc/APIchanges
  2. 28
      libavutil/eval.c
  3. 14
      libavutil/eval.h
  4. 2
      libavutil/version.h

@ -15,6 +15,9 @@ libavutil: 2017-10-21
API changes, most recent first:
2019-12-27 - xxxxxxxxxx - lavu 56.38.100 - eval.h
Add av_expr_count_func().
2019-12-xx - xxxxxxxxxx - lavu 56.37.100 - buffer.h
Add av_buffer_pool_buffer_get_opaque().

@ -166,8 +166,8 @@ struct AVExpr {
e_sgn,
} type;
double value; // is sign in other types
int const_index;
union {
int const_index;
double (*func0)(double);
double (*func1)(void *, double);
double (*func2)(void *, double, double);
@ -185,7 +185,7 @@ static double eval_expr(Parser *p, AVExpr *e)
{
switch (e->type) {
case e_value: return e->value;
case e_const: return e->value * p->const_values[e->a.const_index];
case e_const: return e->value * p->const_values[e->const_index];
case e_func0: return e->value * e->a.func0(eval_expr(p, e->param[0]));
case e_func1: return e->value * e->a.func1(p->opaque, eval_expr(p, e->param[0]));
case e_func2: return e->value * e->a.func2(p->opaque, eval_expr(p, e->param[0]), eval_expr(p, e->param[1]));
@ -367,7 +367,7 @@ static int parse_primary(AVExpr **e, Parser *p)
if (strmatch(p->s, p->const_names[i])) {
p->s+= strlen(p->const_names[i]);
d->type = e_const;
d->a.const_index = i;
d->const_index = i;
*e = d;
return 0;
}
@ -478,6 +478,7 @@ static int parse_primary(AVExpr **e, Parser *p)
if (strmatch(next, p->func1_names[i])) {
d->a.func1 = p->funcs1[i];
d->type = e_func1;
d->const_index = i;
*e = d;
return 0;
}
@ -487,6 +488,7 @@ static int parse_primary(AVExpr **e, Parser *p)
if (strmatch(next, p->func2_names[i])) {
d->a.func2 = p->funcs2[i];
d->type = e_func2;
d->const_index = i;
*e = d;
return 0;
}
@ -735,22 +737,32 @@ end:
return ret;
}
int av_expr_count_vars(AVExpr *e, unsigned *counter, int size)
static int expr_count(AVExpr *e, unsigned *counter, int size, int type)
{
int i;
if (!e || !counter || !size)
return AVERROR(EINVAL);
for (i = 0; e->type != e_const && i < 3 && e->param[i]; i++)
av_expr_count_vars(e->param[i], counter, size);
for (i = 0; e->type != type && i < 3 && e->param[i]; i++)
expr_count(e->param[i], counter, size, type);
if (e->type == e_const && e->a.const_index < size)
counter[e->a.const_index]++;
if (e->type == type && e->const_index < size)
counter[e->const_index]++;
return 0;
}
int av_expr_count_vars(AVExpr *e, unsigned *counter, int size)
{
return expr_count(e, counter, size, e_const);
}
int av_expr_count_func(AVExpr *e, unsigned *counter, int size, int arg)
{
return expr_count(e, counter, size, ((int[]){e_const, e_func1, e_func2})[arg]);
}
double av_expr_eval(AVExpr *e, const double *const_values, void *opaque)
{
Parser p = { 0 };

@ -96,6 +96,20 @@ double av_expr_eval(AVExpr *e, const double *const_values, void *opaque);
*/
int av_expr_count_vars(AVExpr *e, unsigned *counter, int size);
/**
* Track the presence of user provided functions and their number of occurrences
* in a parsed expression.
*
* @param counter a zero-initialized array where the count of each function will be stored
* if you passed 5 functions with 2 arguments to av_expr_parse()
* then for arg=2 this will use upto 5 entries.
* @param size size of array
* @param arg number of arguments the counted functions have
* @return 0 on success, a negative value indicates that no expression or array was passed
* or size was zero
*/
int av_expr_count_func(AVExpr *e, unsigned *counter, int size, int arg);
/**
* Free a parsed expression previously created with av_expr_parse().
*/

@ -79,7 +79,7 @@
*/
#define LIBAVUTIL_VERSION_MAJOR 56
#define LIBAVUTIL_VERSION_MINOR 37
#define LIBAVUTIL_VERSION_MINOR 38
#define LIBAVUTIL_VERSION_MICRO 100
#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \

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