/*
- * 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 "libavutil/avutil.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
-
typedef struct Parser{
int stack_index;
char *s;
- double *const_value;
- const char **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 double *const_value;
+ const char * const *const_name; // NULL terminated
+ double (* const *func1)(void *, double a); // NULL terminated
+ const char * const *func1_name; // NULL terminated
+ double (* const *func2)(void *, double a, double b); // NULL terminated
+ const char * const *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
return 1;
}
-struct ff_expr_s {
+struct AVExpr {
enum {
e_value, e_const, e_func0, e_func1, e_func2,
e_squish, e_gauss, e_ld,
double (*func1)(void *, double);
double (*func2)(void *, double, double);
} a;
- AVEvalExpr * param[2];
+ struct AVExpr *param[2];
};
-static double eval_expr(Parser * p, AVEvalExpr * e) {
+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_value[e->a.const_index];
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_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[clip(d, 0, VARS-1)]= d2);
+ case e_st : return e->value * (p->var[av_clip(d, 0, VARS-1)]= d2);
}
}
}
return NAN;
}
-static AVEvalExpr * parse_expr(Parser *p);
+static AVExpr * parse_expr(Parser *p);
-void ff_eval_free(AVEvalExpr * e) {
+void ff_free_expr(AVExpr * e) {
if (!e) return;
- ff_eval_free(e->param[0]);
- ff_eval_free(e->param[1]);
+ ff_free_expr(e->param[0]);
+ ff_free_expr(e->param[1]);
av_freep(&e);
}
-static AVEvalExpr * parse_primary(Parser *p) {
- AVEvalExpr * d = av_mallocz(sizeof(AVEvalExpr));
+static AVExpr * parse_primary(Parser *p) {
+ AVExpr * d = av_mallocz(sizeof(AVExpr));
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);
+ ff_free_expr(d);
return NULL;
}
p->s++; // "("
d = parse_expr(p);
if(p->s[0] != ')'){
*p->error = "missing )";
- ff_eval_free(d);
+ ff_free_expr(d);
return NULL;
}
p->s++; // ")"
}
if(p->s[0] != ')'){
*p->error = "missing )";
- ff_eval_free(d);
+ ff_free_expr(d);
return NULL;
}
p->s++; // ")"
else if( strmatch(next, "eq" ) ) d->type = e_eq;
else if( strmatch(next, "gte" ) ) 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, "lte" ) ) { AVExpr * tmp = d->param[1]; d->param[1] = d->param[0]; d->param[0] = tmp; d->type = e_gt; }
+ else if( strmatch(next, "lt" ) ) { AVExpr * 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;
}
*p->error = "unknown function";
- ff_eval_free(d);
+ ff_free_expr(d);
return NULL;
}
return d;
}
-static AVEvalExpr * new_eval_expr(int type, int value, AVEvalExpr *p0, AVEvalExpr *p1){
- AVEvalExpr * e = av_mallocz(sizeof(AVEvalExpr));
+static AVExpr * new_eval_expr(int type, int value, AVExpr *p0, AVExpr *p1){
+ AVExpr * e = av_mallocz(sizeof(AVExpr));
+ if (!e)
+ return NULL;
e->type =type ;
e->value =value ;
e->param[0] =p0 ;
return e;
}
-static AVEvalExpr * parse_pow(Parser *p, int *sign){
+static AVExpr * parse_pow(Parser *p, int *sign){
*sign= (*p->s == '+') - (*p->s == '-');
p->s += *sign&1;
return parse_primary(p);
}
-static AVEvalExpr * parse_factor(Parser *p){
+static AVExpr * parse_factor(Parser *p){
int sign, sign2;
- AVEvalExpr * e = parse_pow(p, &sign);
+ AVExpr * e = parse_pow(p, &sign);
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);
return e;
}
-static AVEvalExpr * parse_term(Parser *p){
- AVEvalExpr * e = parse_factor(p);
+static AVExpr * parse_term(Parser *p){
+ AVExpr * e = parse_factor(p);
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;
}
-static AVEvalExpr * parse_subexpr(Parser *p) {
- AVEvalExpr * e = parse_term(p);
+static AVExpr * parse_subexpr(Parser *p) {
+ AVExpr * 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;
}
-static AVEvalExpr * parse_expr(Parser *p) {
- AVEvalExpr * e;
+static AVExpr * parse_expr(Parser *p) {
+ AVExpr * e;
if(p->stack_index <= 0) //protect against stack overflows
return NULL;
while(*p->s == ';') {
p->s++;
e= new_eval_expr(e_last, 1, e, parse_subexpr(p));
+ if (!e)
+ return NULL;
};
p->stack_index++;
return e;
}
-static int verify_expr(AVEvalExpr * e) {
+static int verify_expr(AVExpr * e) {
if (!e) return 0;
switch (e->type) {
case e_value:
}
}
-AVEvalExpr * ff_parse(char *s, const char **const_name,
- double (**func1)(void *, double), const char **func1_name,
- double (**func2)(void *, double, double), char **func2_name,
- char **error){
+AVExpr *ff_parse_expr(const char *s, const char * const *const_name,
+ double (* const *func1)(void *, double), const char * const *func1_name,
+ double (* const *func2)(void *, double, double), const char * const *func2_name,
+ const char **error){
Parser p;
- AVEvalExpr * e;
- char w[strlen(s) + 1], * wp = w;
+ AVExpr *e = NULL;
+ char *w = av_malloc(strlen(s) + 1);
+ char *wp = w;
+
+ if (!w)
+ goto end;
while (*s)
if (!isspace(*s++)) *wp++ = s[-1];
e = parse_expr(&p);
if (!verify_expr(e)) {
- ff_eval_free(e);
- return NULL;
+ ff_free_expr(e);
+ e = NULL;
}
+end:
+ av_free(w);
return e;
}
-double ff_parse_eval(AVEvalExpr * e, double *const_value, void *opaque) {
+double ff_eval_expr(AVExpr * 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 (**func1)(void *, double), const char **func1_name,
- double (**func2)(void *, double, double), char **func2_name,
- void *opaque, char **error){
- AVEvalExpr * e = ff_parse(s, const_name, func1, func1_name, func2, func2_name, error);
+double ff_parse_and_eval_expr(const char *s, const double *const_value, const char * const *const_name,
+ double (* const *func1)(void *, double), const char * const *func1_name,
+ double (* const *func2)(void *, double, double), const char * const *func2_name,
+ void *opaque, const char **error){
+ AVExpr * e = ff_parse_expr(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);
+ d = ff_eval_expr(e, const_value, opaque);
+ ff_free_expr(e);
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_parse_and_eval_expr("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_parse_and_eval_expr("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_parse_and_eval_expr("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_parse_and_eval_expr")
}
+ return 0;
}
#endif
projects / ffmpeg / blobdiff