/*
* 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,
if(*next=='B') {
d*=8;
- *next++;
+ next++;
}
}
/* if requested, fill in tail with the position after the last parsed
struct ff_expr_s {
enum {
e_value, e_const, e_func0, e_func1, e_func2,
- e_squish, e_gauss,
+ 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_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[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 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;
else if( strmatch(next, "max" ) ) d->type = e_max;
else if( strmatch(next, "min" ) ) d->type = e_min;
else if( strmatch(next, "eq" ) ) d->type = e_eq;
- else if( strmatch(next, "gt" ) ) d->type = e_gt;
else if( strmatch(next, "gte" ) ) d->type = e_gte;
- 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, "gt" ) ) d->type = e_gt;
else if( strmatch(next, "lte" ) ) { AVEvalExpr * tmp = d->param[1]; d->param[1] = d->param[0]; d->param[0] = tmp; d->type = e_gt; }
+ 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])){
return d;
}
+static AVEvalExpr * new_eval_expr(int type, int value, AVEvalExpr *p0, AVEvalExpr *p1){
+ AVEvalExpr * e = av_mallocz(sizeof(AVEvalExpr));
+ e->type =type ;
+ e->value =value ;
+ e->param[0] =p0 ;
+ e->param[1] =p1 ;
+ return e;
+}
+
static AVEvalExpr * parse_pow(Parser *p, int *sign){
*sign= (*p->s == '+') - (*p->s == '-');
p->s += *sign&1;
int sign, sign2;
AVEvalExpr * e = parse_pow(p, &sign);
while(p->s[0]=='^'){
- AVEvalExpr * tmp = av_mallocz(sizeof(AVEvalExpr));
-
p->s++;
-
- tmp->type = e_pow;
- tmp->value = 1.;
- tmp->param[0] = e;
- tmp->param[1] = parse_pow(p, &sign2);
- if (tmp->param[1]) tmp->param[1]->value *= (sign2|1);
- e = tmp;
+ e= new_eval_expr(e_pow, 1, e, parse_pow(p, &sign2));
+ if (e->param[1]) e->param[1]->value *= (sign2|1);
}
if (e) e->value *= (sign|1);
return e;
static AVEvalExpr * parse_term(Parser *p){
AVEvalExpr * e = parse_factor(p);
while(p->s[0]=='*' || p->s[0]=='/'){
- AVEvalExpr * tmp = av_mallocz(sizeof(AVEvalExpr));
- if(*p->s++ == '*') tmp->type = e_mul;
- else tmp->type = e_div;
- tmp->value = 1.;
- tmp->param[0] = e;
- tmp->param[1] = parse_factor(p);
- e = tmp;
+ int c= *p->s++;
+ e= new_eval_expr(c == '*' ? e_mul : e_div, 1, e, parse_factor(p));
}
return e;
}
+static AVEvalExpr * parse_subexpr(Parser *p) {
+ AVEvalExpr * e = parse_term(p);
+ while(*p->s == '+' || *p->s == '-') {
+ e= new_eval_expr(e_add, 1, e, parse_term(p));
+ };
+
+ return e;
+}
+
static AVEvalExpr * parse_expr(Parser *p) {
AVEvalExpr * e;
return NULL;
p->stack_index--;
- e = parse_term(p);
+ e = parse_subexpr(p);
- while(*p->s == '+' || *p->s == '-') {
- AVEvalExpr * tmp = av_mallocz(sizeof(AVEvalExpr));
- tmp->type = e_add;
- tmp->value = 1.;
- tmp->param[0] = e;
- tmp->param[1] = parse_term(p);
- e = tmp;
+ while(*p->s == ';') {
+ p->s++;
+ e= new_eval_expr(e_last, 1, e, parse_subexpr(p));
};
p->stack_index++;
case e_func0:
case e_func1:
case e_squish:
+ case e_ld:
case e_gauss: return verify_expr(e->param[0]);
default: return verify_expr(e->param[0]) && verify_expr(e->param[1]);
}
}
-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
projects / ffmpeg / blobdiff