/*
* simple arithmetic expression evaluator
*
- * Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
+ * Copyright (c) 2002-2006 Michael Niedermayer <michaelni@gmx.at>
+ * Copyright (c) 2006 Oded Shimon <ods15@ods15.dyndns.org>
*
* This file is part of FFmpeg.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
*/
/**
- * @file eval.c
+ * @file libavcodec/eval.c
* simple arithmetic expression evaluator.
*
* see http://joe.hotchkiss.com/programming/eval/eval.html
*/
-#include "avcodec.h"
-#include "mpegvideo.h"
-#include "eval.h"
-
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
-#ifndef NAN
- #define NAN 0.0/0.0
-#endif
-
-#ifndef M_PI
-#define M_PI 3.14159265358979323846
-#endif
+#include "libavutil/mathematics.h"
+#include "avcodec.h"
+#include "eval.h"
typedef struct Parser{
int stack_index;
char *s;
- double *const_value;
- const char **const_name; // NULL terminated
+ const double *const_value;
+ const char * const *const_name; // NULL terminated
double (**func1)(void *, double a); // NULL terminated
const char **func1_name; // NULL terminated
double (**func2)(void *, double a, double b); // NULL terminated
- char **func2_name; // NULL terminated
+ const char **func2_name; // NULL terminated
void *opaque;
- char **error;
+ const char **error;
#define VARS 10
double var[VARS];
} Parser;
-static int8_t si_prefixes['z' - 'E' + 1]={
+static const int8_t si_prefixes['z' - 'E' + 1]={
['y'-'E']= -24,
['z'-'E']= -21,
['a'-'E']= -18,
['Y'-'E']= 24,
};
-/** strtod() function extended with 'k', 'M', 'G', 'ki', 'Mi', 'Gi' and 'B'
- * postfixes. This allows using f.e. kB, MiB, G and B as a postfix. This
- * function assumes that the unit of numbers is bits not bytes.
- */
-static double av_strtod(const char *name, char **tail) {
+double av_strtod(const char *numstr, char **tail) {
double d;
char *next;
- d = strtod(name, &next);
+ d = strtod(numstr, &next);
/* if parsing succeeded, check for and interpret postfixes */
- if (next!=name) {
+ if (next!=numstr) {
if(*next >= 'E' && *next <= 'z'){
int e= si_prefixes[*next - 'E'];
if(*next=='B') {
d*=8;
- *next++;
+ next++;
}
}
/* if requested, fill in tail with the position after the last parsed
e_squish, e_gauss, e_ld,
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_last, e_st, e_while,
} type;
double value; // is sign in other types
union {
case e_func2: return e->value * e->a.func2(p->opaque, eval_expr(p, e->param[0]), eval_expr(p, e->param[1]));
case e_squish: return 1/(1+exp(4*eval_expr(p, e->param[0])));
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[clip(eval_expr(p, e->param[0]), 0, VARS-1)];
+ case e_ld: return e->value * p->var[av_clip(eval_expr(p, e->param[0]), 0, VARS-1)];
+ case e_while: {
+ double d = NAN;
+ while(eval_expr(p, e->param[0]))
+ d=eval_expr(p, e->param[1]);
+ return d;
+ }
default: {
double d = eval_expr(p, e->param[0]);
double d2 = eval_expr(p, e->param[1]);
case e_mul: return e->value * (d * d2);
case e_div: return e->value * (d / d2);
case e_add: return e->value * (d + d2);
- case e_last:return d2;
- case e_st : return e->value * (p->var[clip(d, 0, VARS-1)]= d2);
+ case e_last:return e->value * d2;
+ case e_st : return e->value * (p->var[av_clip(d, 0, VARS-1)]= d2);
}
}
}
char *next= p->s;
int i;
+ if (!d)
+ return NULL;
+
/* number */
d->value = av_strtod(p->s, &next);
if(next != p->s){
p->s= strchr(p->s, '(');
if(p->s==NULL){
- *p->error = "missing (";
+ *p->error = "undefined constant or missing (";
p->s= next;
ff_eval_free(d);
return NULL;
else if( strmatch(next, "lt" ) ) { AVEvalExpr * tmp = d->param[1]; d->param[1] = d->param[0]; d->param[0] = tmp; d->type = e_gte; }
else if( strmatch(next, "ld" ) ) d->type = e_ld;
else if( strmatch(next, "st" ) ) d->type = e_st;
+ else if( strmatch(next, "while" ) ) d->type = e_while;
else {
for(i=0; p->func1_name && p->func1_name[i]; i++){
if(strmatch(next, p->func1_name[i])){
static AVEvalExpr * new_eval_expr(int type, int value, AVEvalExpr *p0, AVEvalExpr *p1){
AVEvalExpr * e = av_mallocz(sizeof(AVEvalExpr));
+ if (!e)
+ return NULL;
e->type =type ;
e->value =value ;
e->param[0] =p0 ;
while(p->s[0]=='^'){
p->s++;
e= new_eval_expr(e_pow, 1, e, parse_pow(p, &sign2));
+ if (!e)
+ return NULL;
if (e->param[1]) e->param[1]->value *= (sign2|1);
}
if (e) e->value *= (sign|1);
while(p->s[0]=='*' || p->s[0]=='/'){
int c= *p->s++;
e= new_eval_expr(c == '*' ? e_mul : e_div, 1, e, parse_factor(p));
+ if (!e)
+ return NULL;
}
return e;
}
AVEvalExpr * e = parse_term(p);
while(*p->s == '+' || *p->s == '-') {
e= new_eval_expr(e_add, 1, e, parse_term(p));
+ if (!e)
+ return NULL;
};
return e;
while(*p->s == ';') {
p->s++;
e= new_eval_expr(e_last, 1, e, parse_subexpr(p));
+ if (!e)
+ return NULL;
};
p->stack_index++;
}
}
-AVEvalExpr * ff_parse(char *s, const char **const_name,
+AVEvalExpr * ff_parse(const char *s, const char * const *const_name,
double (**func1)(void *, double), const char **func1_name,
- double (**func2)(void *, double, double), char **func2_name,
- char **error){
+ double (**func2)(void *, double, double), const char **func2_name,
+ const char **error){
Parser p;
- AVEvalExpr * e;
+ AVEvalExpr *e = NULL;
+ char *w = av_malloc(strlen(s) + 1);
+ char *wp = w;
+
+ if (!w)
+ goto end;
+
+ while (*s)
+ if (!isspace(*s++)) *wp++ = s[-1];
+ *wp++ = 0;
p.stack_index=100;
- p.s= s;
+ p.s= w;
p.const_name = const_name;
p.func1 = func1;
p.func1_name = func1_name;
e = parse_expr(&p);
if (!verify_expr(e)) {
ff_eval_free(e);
- return NULL;
+ e = NULL;
}
+end:
+ av_free(w);
return e;
}
-double ff_parse_eval(AVEvalExpr * e, double *const_value, void *opaque) {
+double ff_parse_eval(AVEvalExpr * e, const double *const_value, void *opaque) {
Parser p;
p.const_value= const_value;
return eval_expr(&p, e);
}
-double ff_eval2(char *s, double *const_value, const char **const_name,
+double ff_eval2(const char *s, const double *const_value, const char * const *const_name,
double (**func1)(void *, double), const char **func1_name,
- double (**func2)(void *, double, double), char **func2_name,
- void *opaque, char **error){
+ double (**func2)(void *, double, double), const char **func2_name,
+ void *opaque, const char **error){
AVEvalExpr * e = ff_parse(s, const_name, func1, func1_name, func2, func2_name, error);
double d;
if (!e) return NAN;
return d;
}
-#if LIBAVCODEC_VERSION_INT < ((52<<16)+(0<<8)+0)
-attribute_deprecated 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){
- char *error=NULL;
- double ret;
- ret = ff_eval2(s, const_value, const_name, func1, func1_name, func2, func2_name, opaque, &error);
- if (error)
- av_log(NULL, AV_LOG_ERROR, "Error evaluating \"%s\": %s\n", s, error);
- return ret;
-}
-#endif
-
#ifdef TEST
#undef printf
static double const_values[]={
"E",
0
};
-main(){
+int main(void){
int i;
- printf("%f == 12.7\n", ff_eval("1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)", const_values, const_names, NULL, NULL, NULL, NULL, NULL));
- printf("%f == 0.931322575\n", ff_eval("80G/80Gi", const_values, const_names, NULL, NULL, NULL, NULL, NULL));
+ printf("%f == 12.7\n", ff_eval2("1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)", const_values, const_names, NULL, NULL, NULL, NULL, NULL, NULL));
+ printf("%f == 0.931322575\n", ff_eval2("80G/80Gi", const_values, const_names, NULL, NULL, NULL, NULL, NULL, NULL));
for(i=0; i<1050; i++){
START_TIMER
- ff_eval("1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)", const_values, const_names, NULL, NULL, NULL, NULL, NULL);
- STOP_TIMER("ff_eval")
+ ff_eval2("1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)", const_values, const_names, NULL, NULL, NULL, NULL, NULL, NULL);
+ STOP_TIMER("ff_eval2")
}
+ return 0;
}
#endif
projects / ffmpeg / blobdiff