@@ -30,6 +30,7 @@

 #include "avcodec.h"

 #include "mpegvideo.h"

+#include "eval.h"

 #include <stdio.h>

 #include <stdlib.h>

@@ -57,8 +58,6 @@ typedef struct Parser{

     char **error;

 } Parser;

-static double evalExpression(Parser *p);

-

 static int8_t si_prefixes['z' - 'E' + 1]={

     ['y'-'E']= -24,

     ['z'-'E']= -21,

@@ -126,23 +125,82 @@ static int strmatch(const char *s, const char *prefix){

     return 1;

 }

-static double evalPrimary(Parser *p){

-    double d, d2=NAN;

+struct ff_expr_s {

+    enum {

+        e_value, e_const, e_func0, e_func1, e_func2,

+        e_squish, e_gauss,

+        e_mod, e_max, e_min, e_eq, e_gt, e_gte,

+        e_pow, e_mul, e_div, e_add,

+    } type;

+    double value; // is sign in other types

+    union {

+        int const_index;

+        double (*func0)(double);

+        double (*func1)(void *, double);

+        double (*func2)(void *, double, double);

+    } a;

+    AVEvalExpr * param[2];

+};

+

+static double eval_expr(Parser * p, AVEvalExpr * 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_func0:  return e->value * e->a.func0(eval_expr(p, e->param[0]));

+        case e_func1:  return e->value * e->a.func1(p->opaque, eval_expr(p, e->param[0]));

+        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); }

+        default: {

+            double d = eval_expr(p, e->param[0]);

+            double d2 = eval_expr(p, e->param[1]);

+            switch (e->type) {

+                case e_mod: return e->value * (d - floor(d/d2)*d2);

+                case e_max: return e->value * (d >  d2 ?   d : d2);

+                case e_min: return e->value * (d <  d2 ?   d : d2);

+                case e_eq:  return e->value * (d == d2 ? 1.0 : 0.0);

+                case e_gt:  return e->value * (d >  d2 ? 1.0 : 0.0);

+                case e_gte: return e->value * (d >= d2 ? 1.0 : 0.0);

+                case e_pow: return e->value * pow(d, d2);

+                case e_mul: return e->value * (d * d2);

+                case e_div: return e->value * (d / d2);

+                case e_add: return e->value * (d + d2);

+            }

+        }

+    }

+    return NAN;

+}

+

+static AVEvalExpr * parse_expr(Parser *p);

+

+void ff_eval_free(AVEvalExpr * e) {

+    if (!e) return;

+    ff_eval_free(e->param[0]);

+    ff_eval_free(e->param[1]);

+    av_freep(&e);

+}

+

+static AVEvalExpr * parse_primary(Parser *p) {

+    AVEvalExpr * d = av_mallocz(sizeof(AVEvalExpr));

     char *next= p->s;

     int i;

     /* number */

-    d= av_strtod(p->s, &next);

+    d->value = av_strtod(p->s, &next);

     if(next != p->s){

+        d->type = e_value;

         p->s= next;

         return d;

     }

+    d->value = 1;

     /* named constants */

     for(i=0; p->const_name && p->const_name[i]; i++){

         if(strmatch(p->s, p->const_name[i])){

             p->s+= strlen(p->const_name[i]);

-            return p->const_value[i];

+            d->type = e_const;

+            d->a.const_index = i;

+            return d;

         }

     }

@@ -150,126 +208,198 @@ static double evalPrimary(Parser *p){

     if(p->s==NULL){

         *p->error = "missing (";

         p->s= next;

-        return NAN;

+        ff_eval_free(d);

+        return NULL;

     }

     p->s++; // "("

-    d= evalExpression(p);

+    if (*next == '(') { // special case do-nothing

+        av_freep(&d);

+        d = parse_expr(p);

+        if(p->s[0] != ')'){

+            *p->error = "missing )";

+            ff_eval_free(d);

+            return NULL;

+        }

+        p->s++; // ")"

+        return d;

+    }

+    d->param[0] = parse_expr(p);

     if(p->s[0]== ','){

         p->s++; // ","

-        d2= evalExpression(p);

+        d->param[1] = parse_expr(p);

     }

     if(p->s[0] != ')'){

         *p->error = "missing )";

-        return NAN;

+        ff_eval_free(d);

+        return NULL;

     }

     p->s++; // ")"

-         if( strmatch(next, "sinh"  ) ) d= sinh(d);

-    else if( strmatch(next, "cosh"  ) ) d= cosh(d);

-    else if( strmatch(next, "tanh"  ) ) d= tanh(d);

-    else if( strmatch(next, "sin"   ) ) d= sin(d);

-    else if( strmatch(next, "cos"   ) ) d= cos(d);

-    else if( strmatch(next, "tan"   ) ) d= tan(d);

-    else if( strmatch(next, "atan"  ) ) d= atan(d);

-    else if( strmatch(next, "asin"  ) ) d= asin(d);

-    else if( strmatch(next, "acos"  ) ) d= acos(d);

-    else if( strmatch(next, "exp"   ) ) d= exp(d);

-    else if( strmatch(next, "log"   ) ) d= log(d);

-    else if( strmatch(next, "squish") ) d= 1/(1+exp(4*d));

-    else if( strmatch(next, "gauss" ) ) d= exp(-d*d/2)/sqrt(2*M_PI);

-    else if( strmatch(next, "abs"   ) ) d= fabs(d);

-    else if( strmatch(next, "mod"   ) ) d-= floor(d/d2)*d2;

-    else if( strmatch(next, "max"   ) ) d= d >  d2 ?   d : d2;

-    else if( strmatch(next, "min"   ) ) d= d <  d2 ?   d : d2;

-    else if( strmatch(next, "gt"    ) ) d= d >  d2 ? 1.0 : 0.0;

-    else if( strmatch(next, "gte"   ) ) d= d >= d2 ? 1.0 : 0.0;

-    else if( strmatch(next, "lt"    ) ) d= d >  d2 ? 0.0 : 1.0;

-    else if( strmatch(next, "lte"   ) ) d= d >= d2 ? 0.0 : 1.0;

-    else if( strmatch(next, "eq"    ) ) d= d == d2 ? 1.0 : 0.0;

-    else if( strmatch(next, "("     ) ) d= d;

-//    else if( strmatch(next, "l1"    ) ) d= 1 + d2*(d - 1);

-//    else if( strmatch(next, "sq01"  ) ) d= (d >= 0.0 && d <=1.0) ? 1.0 : 0.0;

-    else{

+    d->type = e_func0;

+         if( strmatch(next, "sinh"  ) ) d->a.func0 = sinh;

+    else if( strmatch(next, "cosh"  ) ) d->a.func0 = cosh;

+    else if( strmatch(next, "tanh"  ) ) d->a.func0 = tanh;

+    else if( strmatch(next, "sin"   ) ) d->a.func0 = sin;

+    else if( strmatch(next, "cos"   ) ) d->a.func0 = cos;

+    else if( strmatch(next, "tan"   ) ) d->a.func0 = tan;

+    else if( strmatch(next, "atan"  ) ) d->a.func0 = atan;

+    else if( strmatch(next, "asin"  ) ) d->a.func0 = asin;

+    else if( strmatch(next, "acos"  ) ) d->a.func0 = acos;

+    else if( strmatch(next, "exp"   ) ) d->a.func0 = exp;

+    else if( strmatch(next, "log"   ) ) d->a.func0 = log;

+    else if( strmatch(next, "abs"   ) ) d->a.func0 = fabs;

+    else if( strmatch(next, "squish") ) d->type = e_squish;

+    else if( strmatch(next, "gauss" ) ) d->type = e_gauss;

+    else if( strmatch(next, "mod"   ) ) d->type = e_mod;

+    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, "lte"   ) ) { AVEvalExpr * tmp = d->param[1]; d->param[1] = d->param[0]; d->param[0] = tmp; d->type = e_gt; }

+    else {

         for(i=0; p->func1_name && p->func1_name[i]; i++){

             if(strmatch(next, p->func1_name[i])){

-                return p->func1[i](p->opaque, d);

+                d->a.func1 = p->func1[i];

+                d->type = e_func1;

+                return d;

             }

         }

         for(i=0; p->func2_name && p->func2_name[i]; i++){

             if(strmatch(next, p->func2_name[i])){

-                return p->func2[i](p->opaque, d, d2);

+                d->a.func2 = p->func2[i];

+                d->type = e_func2;

+                return d;

             }

         }

         *p->error = "unknown function";

-        return NAN;

+        ff_eval_free(d);

+        return NULL;

     }

     return d;

 }

-static double evalPow(Parser *p, int *sign){

+static AVEvalExpr * parse_pow(Parser *p, int *sign){

     *sign= (*p->s == '+') - (*p->s == '-');

     p->s += *sign&1;

-    return evalPrimary(p);

+    return parse_primary(p);

 }

-static double evalFactor(Parser *p){

+static AVEvalExpr * parse_factor(Parser *p){

     int sign, sign2;

-    double ret, e;

-    ret= evalPow(p, &sign);

+    AVEvalExpr * e = parse_pow(p, &sign);

     while(p->s[0]=='^'){

+        AVEvalExpr * tmp = av_mallocz(sizeof(AVEvalExpr));

+

         p->s++;

-        e= evalPow(p, &sign2);

-        ret= pow(ret, (sign2|1) * e);

+

+        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;

     }

-    return (sign|1) * ret;

+    if (e) e->value *= (sign|1);

+    return e;

 }

-static double evalTerm(Parser *p){

-    double ret= evalFactor(p);

+static AVEvalExpr * parse_term(Parser *p){

+    AVEvalExpr * e = parse_factor(p);

     while(p->s[0]=='*' || p->s[0]=='/'){

-        if(*p->s++ == '*') ret*= evalFactor(p);

-        else               ret/= evalFactor(p);

+        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;

     }

-    return ret;

+    return e;

 }

-static double evalExpression(Parser *p){

-    double ret= 0;

+static AVEvalExpr * parse_expr(Parser *p) {

+    AVEvalExpr * e;

     if(p->stack_index <= 0) //protect against stack overflows

-        return NAN;

+        return NULL;

     p->stack_index--;

-    do{

-        ret += evalTerm(p);

-    }while(*p->s == '+' || *p->s == '-');

+    e = parse_term(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;

+    };

     p->stack_index++;

-    return ret;

+    return e;

 }

-double ff_eval2(char *s, double *const_value, const char **const_name,

+static int verify_expr(AVEvalExpr * e) {

+    if (!e) return 0;

+    switch (e->type) {

+        case e_value:

+        case e_const: return 1;

+        case e_func0:

+        case e_func1:

+        case e_squish:

+        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,

                double (**func1)(void *, double), const char **func1_name,

                double (**func2)(void *, double, double), char **func2_name,

-               void *opaque, char **error){

+               char **error){

     Parser p;

+    AVEvalExpr * e;

     p.stack_index=100;

     p.s= s;

-    p.const_value= const_value;

     p.const_name = const_name;

     p.func1      = func1;

     p.func1_name = func1_name;

     p.func2      = func2;

     p.func2_name = func2_name;

-    p.opaque     = opaque;

     p.error= error;

-    return evalExpression(&p);

+    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) {

+    Parser p;

+

+    p.const_value= const_value;

+    p.opaque     = opaque;

+    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 d;

+    if (!e) return NAN;

+    d = ff_parse_eval(e, const_value, opaque);

+    ff_eval_free(e);

+    return d;

 }

 #if LIBAVCODEC_VERSION_INT < ((52<<16)+(0<<8)+0)

@@ -39,4 +39,12 @@ double ff_eval2(char *s, double *const_value, const char **const_name,

                double (**func2)(void *, double, double), char **func2_name,

                void *opaque, char **error);

+typedef struct ff_expr_s AVEvalExpr;

+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);

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

+void ff_eval_free(AVEvalExpr * e);

+

 #endif /* AVCODEC_EVAL_H */