eval.h File Reference

Go to the source code of this file.

Typedefs
typedef ff_expr_s	AVEvalExpr
Functions
double	ff_eval (char *s, double *const_value, const char **const_name, double(**func1)(void *, double), const char **func1_name, double(**func2)(void *, double, double), char **func2_name, void *opaque)
double	ff_eval2 (const char *s, double *const_value, const char **const_name, double(**func1)(void *, double), const char **func1_name, double(**func2)(void *, double, double), char **func2_name, void *opaque, const char **error)
AVEvalExpr *	ff_parse (const char *s, const char **const_name, double(**func1)(void *, double), const char **func1_name, double(**func2)(void *, double, double), char **func2_name, const char **error)
double	ff_parse_eval (AVEvalExpr *e, double *const_value, void *opaque)
void	ff_eval_free (AVEvalExpr *e)

---

Detailed Description

eval header.

Definition in file eval.h.

---

Typedef Documentation

typedef struct ff_expr_s AVEvalExpr

Definition at line 60 of file eval.h.

---

Function Documentation

double ff_eval	(	char *	s,
		double *	const_value,
		const char **	const_name,
		double(**)(void *, double)	func1,
		const char **	func1_name,
		double(**)(void *, double, double)	func2,
		char **	func2_name,
		void *	opaque
	)

Deprecated:

Use ff_eval2 instead

double ff_eval2	(	const char *	s,
		double *	const_value,
		const char **	const_name,
		double(**)(void *, double)	func1,
		const char **	func1_name,
		double(**)(void *, double, double)	func2,
		char **	func2_name,
		void *	opaque,
		const char **	error
	)

Parses and evaluates an expression. Note, this is significantly slower than ff_parse_eval()

Parameters:

	s	expression as a zero terminated string for example "1+2^3+5*5+sin(2/3)"
	func1	NULL terminated array of function pointers for functions which take 1 argument
	func2	NULL terminated array of function pointers for functions which take 2 arguments
	const_name	NULL terminated array of zero terminated strings of constant identifers for example {"PI", "E", 0}
	func1_name	NULL terminated array of zero terminated strings of func1 identifers
	func2_name	NULL terminated array of zero terminated strings of func2 identifers
	error	pointer to a char* which is set to an error message if something goes wrong
	const_value	a zero terminated array of values for the identifers from const_name
	opaque	a pointer which will be passed to all functions from func1 and func2

Returns:

the value of the expression

Definition at line 415 of file eval.c.

References ff_eval_free(), ff_parse(), ff_parse_eval(), and NAN.

Referenced by av_set_string2().

                                                {
    AVEvalExpr * e = ff_parse(s, const_name, func1, func1_name, func2, func2_name, error);
    double d;
    if (!e) return NAN;
    d = ff_parse_eval(e, const_value, opaque);
    ff_eval_free(e);
    return d;
}

void ff_eval_free

(

AVEvalExpr *

e

)

Definition at line 187 of file eval.c.

References av_freep(), ff_eval_free(), and ff_expr_s::param.

Referenced by ff_eval2(), ff_eval_free(), ff_parse(), ff_rate_control_uninit(), and Release().

                                  {
    if (!e) return;
    ff_eval_free(e->param[0]);
    ff_eval_free(e->param[1]);
    av_freep(&e);
}

AVEvalExpr* ff_parse	(	const char *	s,
		const char **	const_name,
		double(**)(void *, double)	func1,
		const char **	func1_name,
		double(**)(void *, double, double)	func2,
		char **	func2_name,
		const char **	error
	)

Parses a expression.

Parameters:

	s	expression as a zero terminated string for example "1+2^3+5*5+sin(2/3)"
	func1	NULL terminated array of function pointers for functions which take 1 argument
	func2	NULL terminated array of function pointers for functions which take 2 arguments
	const_name	NULL terminated array of zero terminated strings of constant identifers for example {"PI", "E", 0}
	func1_name	NULL terminated array of zero terminated strings of func1 identifers
	func2_name	NULL terminated array of zero terminated strings of func2 identifers
	error	pointer to a char* which is set to an error message if something goes wrong

Returns:

AVEvalExpr which must be freed with ff_eval_free by the user when it is not needed anymore NULL if anything went wrong

Definition at line 378 of file eval.c.

References Parser::const_name, Parser::error, ff_eval_free(), Parser::func1, Parser::func1_name, Parser::func2, Parser::func2_name, NULL, parse_expr(), Parser::s, Parser::stack_index, and verify_expr().

Referenced by Configure(), ff_eval2(), and ff_rate_control_init().

                                  {
    Parser p;
    AVEvalExpr * e;
    char w[strlen(s) + 1], * wp = w;

    while (*s)
        if (!isspace(*s++)) *wp++ = s[-1];
    *wp++ = 0;

    p.stack_index=100;
    p.s= w;
    p.const_name = const_name;
    p.func1      = func1;
    p.func1_name = func1_name;
    p.func2      = func2;
    p.func2_name = func2_name;
    p.error= error;

    e = parse_expr(&p);
    if (!verify_expr(e)) {
        ff_eval_free(e);
        return NULL;
    }
    return e;
}

double ff_parse_eval	(	AVEvalExpr *	e,
		double *	const_value,
		void *	opaque
	)

Evaluates a previously parsed expression.

Parameters:

	const_value	a zero terminated array of values for the identifers from ff_parse const_name
	opaque	a pointer which will be passed to all functions from func1 and func2

Returns:

the value of the expression

Definition at line 407 of file eval.c.

References Parser::const_value, eval_expr(), and Parser::opaque.

Referenced by ff_eval2(), get_qscale(), and Process().

                                                                        {
    Parser p;

    p.const_value= const_value;
    p.opaque     = opaque;
    return eval_expr(&p, e);
}

---