/*
* 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>
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
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]))
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);
}
}
}
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;
}
}
-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;
+ char w[strlen(s) + 1], * wp = w;
+
+ 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;
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