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FFmpeg/libavutil/eval.c

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  1. /*

  2.  * Copyright (c) 2002-2006 Michael Niedermayer <michaelni@gmx.at>

  3.  * Copyright (c) 2006 Oded Shimon <ods15@ods15.dyndns.org>

  4.  *

  5.  * This file is part of FFmpeg.

  6.  *

  7.  * FFmpeg is free software; you can redistribute it and/or

  8.  * modify it under the terms of the GNU Lesser General Public

  9.  * License as published by the Free Software Foundation; either

  10.  * version 2.1 of the License, or (at your option) any later version.

  11.  *

  12.  * FFmpeg is distributed in the hope that it will be useful,

  13.  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  14.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  15.  * Lesser General Public License for more details.

  16.  *

  17.  * You should have received a copy of the GNU Lesser General Public

  18.  * License along with FFmpeg; if not, write to the Free Software

  19.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  20.  */

  21. 

  22. /**

  23.  * @file

  24.  * simple arithmetic expression evaluator.

  25.  *

  26.  * see http://joe.hotchkiss.com/programming/eval/eval.html

  27.  */

  28. 

  29. #include "avutil.h"

  30. #include "eval.h"

  31. #include "log.h"

  32. 

  33. typedef struct Parser {

  34.     const AVClass *class;

  35.     int stack_index;

  36.     char *s;

  37.     const double *const_values;

  38.     const char * const *const_names;          // NULL terminated

  39.     double (* const *funcs1)(void *, double a);           // NULL terminated

  40.     const char * const *func1_names;          // NULL terminated

  41.     double (* const *funcs2)(void *, double a, double b); // NULL terminated

  42.     const char * const *func2_names;          // NULL terminated

  43.     void *opaque;

  44.     int log_offset;

  45.     void *log_ctx;

  46. #define VARS 10

  47.     double *var;

  48. } Parser;

  49. 

  50. static const AVClass class = { "Eval", av_default_item_name, NULL, LIBAVUTIL_VERSION_INT, offsetof(Parser,log_offset), offsetof(Parser,log_ctx) };

  51. 

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

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

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

  55.     ['a'-'E']= -18,

  56.     ['f'-'E']= -15,

  57.     ['p'-'E']= -12,

  58.     ['n'-'E']= - 9,

  59.     ['u'-'E']= - 6,

  60.     ['m'-'E']= - 3,

  61.     ['c'-'E']= - 2,

  62.     ['d'-'E']= - 1,

  63.     ['h'-'E']=   2,

  64.     ['k'-'E']=   3,

  65.     ['K'-'E']=   3,

  66.     ['M'-'E']=   6,

  67.     ['G'-'E']=   9,

  68.     ['T'-'E']=  12,

  69.     ['P'-'E']=  15,

  70.     ['E'-'E']=  18,

  71.     ['Z'-'E']=  21,

  72.     ['Y'-'E']=  24,

  73. };

  74. 

  75. static const struct {

  76.     const char *name;

  77.     double value;

  78. } constants[] = {

  79.     { "E",   M_E   },

  80.     { "PI",  M_PI  },

  81.     { "PHI", M_PHI },

  82. };

  83. 

  84. double av_strtod(const char *numstr, char **tail)

  85. {

  86.     double d;

  87.     char *next;

  88.     if(numstr[0]=='0' && (numstr[1]|0x20)=='x') {

  89.         d = strtoul(numstr, &next, 16);

  90.     } else

  91.         d = strtod(numstr, &next);

  92.     /* if parsing succeeded, check for and interpret postfixes */

  93.     if (next!=numstr) {

  94.         if (*next >= 'E' && *next <= 'z') {

  95.             int e= si_prefixes[*next - 'E'];

  96.             if (e) {

  97.                 if (next[1] == 'i') {

  98.                     d*= pow( 2, e/0.3);

  99.                     next+=2;

  100.                 } else {

  101.                     d*= pow(10, e);

  102.                     next++;

  103.                 }

  104.             }

  105.         }

  106. 

  107.         if (*next=='B') {

  108.             d*=8;

  109.             next++;

  110.         }

  111.     }

  112.     /* if requested, fill in tail with the position after the last parsed

  113.        character */

  114.     if (tail)

  115.         *tail = next;

  116.     return d;

  117. }

  118. 

  119. #define IS_IDENTIFIER_CHAR(c) ((c) - '0' <= 9U || (c) - 'a' <= 25U || (c) - 'A' <= 25U || (c) == '_')

  120. 

  121. static int strmatch(const char *s, const char *prefix)

  122. {

  123.     int i;

  124.     for (i=0; prefix[i]; i++) {

  125.         if (prefix[i] != s[i]) return 0;

  126.     }

  127.     /* return 1 only if the s identifier is terminated */

  128.     return !IS_IDENTIFIER_CHAR(s[i]);

  129. }

  130. 

  131. struct AVExpr {

  132.     enum {

  133.         e_value, e_const, e_func0, e_func1, e_func2,

  134.         e_squish, e_gauss, e_ld, e_isnan,

  135.         e_mod, e_max, e_min, e_eq, e_gt, e_gte,

  136.         e_pow, e_mul, e_div, e_add,

  137.         e_last, e_st, e_while, e_taylor, e_floor, e_ceil, e_trunc,

  138.         e_sqrt, e_not, e_random, e_hypot, e_gcd,

  139.         e_if, e_ifnot,

  140.     } type;

  141.     double value; // is sign in other types

  142.     union {

  143.         int const_index;

  144.         double (*func0)(double);

  145.         double (*func1)(void *, double);

  146.         double (*func2)(void *, double, double);

  147.     } a;

  148.     struct AVExpr *param[3];

  149.     double *var;

  150. };

  151. 

  152. static double eval_expr(Parser *p, AVExpr *e)

  153. {

  154.     switch (e->type) {

  155.         case e_value:  return e->value;

  156.         case e_const:  return e->value * p->const_values[e->a.const_index];

  157.         case e_func0:  return e->value * e->a.func0(eval_expr(p, e->param[0]));

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

  159.         case e_func2:  return e->value * e->a.func2(p->opaque, eval_expr(p, e->param[0]), eval_expr(p, e->param[1]));

  160.         case e_squish: return 1/(1+exp(4*eval_expr(p, e->param[0])));

  161.         case e_gauss: { double d = eval_expr(p, e->param[0]); return exp(-d*d/2)/sqrt(2*M_PI); }

  162.         case e_ld:     return e->value * p->var[av_clip(eval_expr(p, e->param[0]), 0, VARS-1)];

  163.         case e_isnan:  return e->value * !!isnan(eval_expr(p, e->param[0]));

  164.         case e_floor:  return e->value * floor(eval_expr(p, e->param[0]));

  165.         case e_ceil :  return e->value * ceil (eval_expr(p, e->param[0]));

  166.         case e_trunc:  return e->value * trunc(eval_expr(p, e->param[0]));

  167.         case e_sqrt:   return e->value * sqrt (eval_expr(p, e->param[0]));

  168.         case e_not:    return e->value * (eval_expr(p, e->param[0]) == 0);

  169.         case e_if:     return e->value * ( eval_expr(p, e->param[0]) ? eval_expr(p, e->param[1]) : 0);

  170.         case e_ifnot:  return e->value * (!eval_expr(p, e->param[0]) ? eval_expr(p, e->param[1]) : 0);

  171.         case e_random:{

  172.             int idx= av_clip(eval_expr(p, e->param[0]), 0, VARS-1);

  173.             uint64_t r= isnan(p->var[idx]) ? 0 : p->var[idx];

  174.             r= r*1664525+1013904223;

  175.             p->var[idx]= r;

  176.             return e->value * (r * (1.0/UINT64_MAX));

  177.         }

  178.         case e_while: {

  179.             double d = NAN;

  180.             while (eval_expr(p, e->param[0]))

  181.                 d=eval_expr(p, e->param[1]);

  182.             return d;

  183.         }

  184.         case e_taylor: {

  185.             double t = 1, d = 0, v;

  186.             double x = eval_expr(p, e->param[1]);

  187.             int id = e->param[2] ? av_clip(eval_expr(p, e->param[2]), 0, VARS-1) : 0;

  188.             int i;

  189.             double var0 = p->var[id];

  190.             for(i=0; i<1000; i++) {

  191.                 double ld = d;

  192.                 p->var[id] = i;

  193.                 v = eval_expr(p, e->param[0]);

  194.                 d += t*v;

  195.                 if(ld==d && v)

  196.                     break;

  197.                 t *= x / (i+1);

  198.             }

  199.             p->var[id] = var0;

  200.             return d;

  201.         }

  202.         default: {

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

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

  205.             switch (e->type) {

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

  207.                 case e_gcd: return e->value * av_gcd(d,d2);

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

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

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

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

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

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

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

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

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

  217.                 case e_last:return e->value * d2;

  218.                 case e_st : return e->value * (p->var[av_clip(d, 0, VARS-1)]= d2);

  219.                 case e_hypot:return e->value * (sqrt(d*d + d2*d2));

  220.             }

  221.         }

  222.     }

  223.     return NAN;

  224. }

  225. 

  226. static int parse_expr(AVExpr **e, Parser *p);

  227. 

  228. void av_expr_free(AVExpr *e)

  229. {

  230.     if (!e) return;

  231.     av_expr_free(e->param[0]);

  232.     av_expr_free(e->param[1]);

  233.     av_expr_free(e->param[2]);

  234.     av_freep(&e->var);

  235.     av_freep(&e);

  236. }

  237. 

  238. static int parse_primary(AVExpr **e, Parser *p)

  239. {

  240.     AVExpr *d = av_mallocz(sizeof(AVExpr));

  241.     char *next = p->s, *s0 = p->s;

  242.     int ret, i;

  243. 

  244.     if (!d)

  245.         return AVERROR(ENOMEM);

  246. 

  247.     /* number */

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

  249.     if (next != p->s) {

  250.         d->type = e_value;

  251.         p->s= next;

  252.         *e = d;

  253.         return 0;

  254.     }

  255.     d->value = 1;

  256. 

  257.     /* named constants */

  258.     for (i=0; p->const_names && p->const_names[i]; i++) {

  259.         if (strmatch(p->s, p->const_names[i])) {

  260.             p->s+= strlen(p->const_names[i]);

  261.             d->type = e_const;

  262.             d->a.const_index = i;

  263.             *e = d;

  264.             return 0;

  265.         }

  266.     }

  267.     for (i = 0; i < FF_ARRAY_ELEMS(constants); i++) {

  268.         if (strmatch(p->s, constants[i].name)) {

  269.             p->s += strlen(constants[i].name);

  270.             d->type = e_value;

  271.             d->value = constants[i].value;

  272.             *e = d;

  273.             return 0;

  274.         }

  275.     }

  276. 

  277.     p->s= strchr(p->s, '(');

  278.     if (p->s==NULL) {

  279.         av_log(p, AV_LOG_ERROR, "Undefined constant or missing '(' in '%s'\n", s0);

  280.         p->s= next;

  281.         av_expr_free(d);

  282.         return AVERROR(EINVAL);

  283.     }

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

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

  286.         av_freep(&d);

  287.         if ((ret = parse_expr(&d, p)) < 0)

  288.             return ret;

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

  290.             av_log(p, AV_LOG_ERROR, "Missing ')' in '%s'\n", s0);

  291.             av_expr_free(d);

  292.             return AVERROR(EINVAL);

  293.         }

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

  295.         *e = d;

  296.         return 0;

  297.     }

  298.     if ((ret = parse_expr(&(d->param[0]), p)) < 0) {

  299.         av_expr_free(d);

  300.         return ret;

  301.     }

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

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

  304.         parse_expr(&d->param[1], p);

  305.     }

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

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

  308.         parse_expr(&d->param[2], p);

  309.     }

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

  311.         av_log(p, AV_LOG_ERROR, "Missing ')' or too many args in '%s'\n", s0);

  312.         av_expr_free(d);

  313.         return AVERROR(EINVAL);

  314.     }

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

  316. 

  317.     d->type = e_func0;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  333.     else if (strmatch(next, "max"   )) d->type = e_max;

  334.     else if (strmatch(next, "min"   )) d->type = e_min;

  335.     else if (strmatch(next, "eq"    )) d->type = e_eq;

  336.     else if (strmatch(next, "gte"   )) d->type = e_gte;

  337.     else if (strmatch(next, "gt"    )) d->type = e_gt;

  338.     else if (strmatch(next, "lte"   )) { AVExpr *tmp = d->param[1]; d->param[1] = d->param[0]; d->param[0] = tmp; d->type = e_gt; }

  339.     else if (strmatch(next, "lt"    )) { AVExpr *tmp = d->param[1]; d->param[1] = d->param[0]; d->param[0] = tmp; d->type = e_gte; }

  340.     else if (strmatch(next, "ld"    )) d->type = e_ld;

  341.     else if (strmatch(next, "isnan" )) d->type = e_isnan;

  342.     else if (strmatch(next, "st"    )) d->type = e_st;

  343.     else if (strmatch(next, "while" )) d->type = e_while;

  344.     else if (strmatch(next, "taylor")) d->type = e_taylor;

  345.     else if (strmatch(next, "floor" )) d->type = e_floor;

  346.     else if (strmatch(next, "ceil"  )) d->type = e_ceil;

  347.     else if (strmatch(next, "trunc" )) d->type = e_trunc;

  348.     else if (strmatch(next, "sqrt"  )) d->type = e_sqrt;

  349.     else if (strmatch(next, "not"   )) d->type = e_not;

  350.     else if (strmatch(next, "pow"   )) d->type = e_pow;

  351.     else if (strmatch(next, "random")) d->type = e_random;

  352.     else if (strmatch(next, "hypot" )) d->type = e_hypot;

  353.     else if (strmatch(next, "gcd"   )) d->type = e_gcd;

  354.     else if (strmatch(next, "if"    )) d->type = e_if;

  355.     else if (strmatch(next, "ifnot" )) d->type = e_ifnot;

  356.     else {

  357.         for (i=0; p->func1_names && p->func1_names[i]; i++) {

  358.             if (strmatch(next, p->func1_names[i])) {

  359.                 d->a.func1 = p->funcs1[i];

  360.                 d->type = e_func1;

  361.                 *e = d;

  362.                 return 0;

  363.             }

  364.         }

  365. 

  366.         for (i=0; p->func2_names && p->func2_names[i]; i++) {

  367.             if (strmatch(next, p->func2_names[i])) {

  368.                 d->a.func2 = p->funcs2[i];

  369.                 d->type = e_func2;

  370.                 *e = d;

  371.                 return 0;

  372.             }

  373.         }

  374. 

  375.         av_log(p, AV_LOG_ERROR, "Unknown function in '%s'\n", s0);

  376.         av_expr_free(d);

  377.         return AVERROR(EINVAL);

  378.     }

  379. 

  380.     *e = d;

  381.     return 0;

  382. }

  383. 

  384. static AVExpr *new_eval_expr(int type, int value, AVExpr *p0, AVExpr *p1)

  385. {

  386.     AVExpr *e = av_mallocz(sizeof(AVExpr));

  387.     if (!e)

  388.         return NULL;

  389.     e->type     =type   ;

  390.     e->value    =value  ;

  391.     e->param[0] =p0     ;

  392.     e->param[1] =p1     ;

  393.     return e;

  394. }

  395. 

  396. static int parse_pow(AVExpr **e, Parser *p, int *sign)

  397. {

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

  399.     p->s += *sign&1;

  400.     return parse_primary(e, p);

  401. }

  402. 

  403. static int parse_factor(AVExpr **e, Parser *p)

  404. {

  405.     int sign, sign2, ret;

  406.     AVExpr *e0, *e1, *e2;

  407.     if ((ret = parse_pow(&e0, p, &sign)) < 0)

  408.         return ret;

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

  410.         e1 = e0;

  411.         p->s++;

  412.         if ((ret = parse_pow(&e2, p, &sign2)) < 0) {

  413.             av_expr_free(e1);

  414.             return ret;

  415.         }

  416.         e0 = new_eval_expr(e_pow, 1, e1, e2);

  417.         if (!e0) {

  418.             av_expr_free(e1);

  419.             av_expr_free(e2);

  420.             return AVERROR(ENOMEM);

  421.         }

  422.         if (e0->param[1]) e0->param[1]->value *= (sign2|1);

  423.     }

  424.     if (e0) e0->value *= (sign|1);

  425. 

  426.     *e = e0;

  427.     return 0;

  428. }

  429. 

  430. static int parse_term(AVExpr **e, Parser *p)

  431. {

  432.     int ret;

  433.     AVExpr *e0, *e1, *e2;

  434.     if ((ret = parse_factor(&e0, p)) < 0)

  435.         return ret;

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

  437.         int c= *p->s++;

  438.         e1 = e0;

  439.         if ((ret = parse_factor(&e2, p)) < 0) {

  440.             av_expr_free(e1);

  441.             return ret;

  442.         }

  443.         e0 = new_eval_expr(c == '*' ? e_mul : e_div, 1, e1, e2);

  444.         if (!e0) {

  445.             av_expr_free(e1);

  446.             av_expr_free(e2);

  447.             return AVERROR(ENOMEM);

  448.         }

  449.     }

  450.     *e = e0;

  451.     return 0;

  452. }

  453. 

  454. static int parse_subexpr(AVExpr **e, Parser *p)

  455. {

  456.     int ret;

  457.     AVExpr *e0, *e1, *e2;

  458.     if ((ret = parse_term(&e0, p)) < 0)

  459.         return ret;

  460.     while (*p->s == '+' || *p->s == '-') {

  461.         e1 = e0;

  462.         if ((ret = parse_term(&e2, p)) < 0) {

  463.             av_expr_free(e1);

  464.             return ret;

  465.         }

  466.         e0 = new_eval_expr(e_add, 1, e1, e2);

  467.         if (!e0) {

  468.             av_expr_free(e1);

  469.             av_expr_free(e2);

  470.             return AVERROR(ENOMEM);

  471.         }

  472.     };

  473. 

  474.     *e = e0;

  475.     return 0;

  476. }

  477. 

  478. static int parse_expr(AVExpr **e, Parser *p)

  479. {

  480.     int ret;

  481.     AVExpr *e0, *e1, *e2;

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

  483.         return AVERROR(EINVAL);

  484.     p->stack_index--;

  485. 

  486.     if ((ret = parse_subexpr(&e0, p)) < 0)

  487.         return ret;

  488.     while (*p->s == ';') {

  489.         p->s++;

  490.         e1 = e0;

  491.         if ((ret = parse_subexpr(&e2, p)) < 0) {

  492.             av_expr_free(e1);

  493.             return ret;

  494.         }

  495.         e0 = new_eval_expr(e_last, 1, e1, e2);

  496.         if (!e0) {

  497.             av_expr_free(e1);

  498.             av_expr_free(e2);

  499.             return AVERROR(ENOMEM);

  500.         }

  501.     };

  502. 

  503.     p->stack_index++;

  504.     *e = e0;

  505.     return 0;

  506. }

  507. 

  508. static int verify_expr(AVExpr *e)

  509. {

  510.     if (!e) return 0;

  511.     switch (e->type) {

  512.         case e_value:

  513.         case e_const: return 1;

  514.         case e_func0:

  515.         case e_func1:

  516.         case e_squish:

  517.         case e_ld:

  518.         case e_gauss:

  519.         case e_isnan:

  520.         case e_floor:

  521.         case e_ceil:

  522.         case e_trunc:

  523.         case e_sqrt:

  524.         case e_not:

  525.         case e_random:

  526.             return verify_expr(e->param[0]) && !e->param[1];

  527.         case e_taylor:

  528.             return verify_expr(e->param[0]) && verify_expr(e->param[1])

  529.                    && (!e->param[2] || verify_expr(e->param[2]));

  530.         default: return verify_expr(e->param[0]) && verify_expr(e->param[1]) && !e->param[2];

  531.     }

  532. }

  533. 

  534. int av_expr_parse(AVExpr **expr, const char *s,

  535.                   const char * const *const_names,

  536.                   const char * const *func1_names, double (* const *funcs1)(void *, double),

  537.                   const char * const *func2_names, double (* const *funcs2)(void *, double, double),

  538.                   int log_offset, void *log_ctx)

  539. {

  540.     Parser p = { 0 };

  541.     AVExpr *e = NULL;

  542.     char *w = av_malloc(strlen(s) + 1);

  543.     char *wp = w;

  544.     const char *s0 = s;

  545.     int ret = 0;

  546. 

  547.     if (!w)

  548.         return AVERROR(ENOMEM);

  549. 

  550.     while (*s)

  551.         if (!isspace(*s++)) *wp++ = s[-1];

  552.     *wp++ = 0;

  553. 

  554.     p.class      = &class;

  555.     p.stack_index=100;

  556.     p.s= w;

  557.     p.const_names = const_names;

  558.     p.funcs1      = funcs1;

  559.     p.func1_names = func1_names;

  560.     p.funcs2      = funcs2;

  561.     p.func2_names = func2_names;

  562.     p.log_offset = log_offset;

  563.     p.log_ctx    = log_ctx;

  564. 

  565.     if ((ret = parse_expr(&e, &p)) < 0)

  566.         goto end;

  567.     if (*p.s) {

  568.         av_expr_free(e);

  569.         av_log(&p, AV_LOG_ERROR, "Invalid chars '%s' at the end of expression '%s'\n", p.s, s0);

  570.         ret = AVERROR(EINVAL);

  571.         goto end;

  572.     }

  573.     if (!verify_expr(e)) {

  574.         av_expr_free(e);

  575.         ret = AVERROR(EINVAL);

  576.         goto end;

  577.     }

  578.     e->var= av_mallocz(sizeof(double) *VARS);

  579.     *expr = e;

  580. end:

  581.     av_free(w);

  582.     return ret;

  583. }

  584. 

  585. double av_expr_eval(AVExpr *e, const double *const_values, void *opaque)

  586. {

  587.     Parser p = { 0 };

  588.     p.var= e->var;

  589. 

  590.     p.const_values = const_values;

  591.     p.opaque     = opaque;

  592.     return eval_expr(&p, e);

  593. }

  594. 

  595. int av_expr_parse_and_eval(double *d, const char *s,

  596.                            const char * const *const_names, const double *const_values,

  597.                            const char * const *func1_names, double (* const *funcs1)(void *, double),

  598.                            const char * const *func2_names, double (* const *funcs2)(void *, double, double),

  599.                            void *opaque, int log_offset, void *log_ctx)

  600. {

  601.     AVExpr *e = NULL;

  602.     int ret = av_expr_parse(&e, s, const_names, func1_names, funcs1, func2_names, funcs2, log_offset, log_ctx);

  603. 

  604.     if (ret < 0) {

  605.         *d = NAN;

  606.         return ret;

  607.     }

  608.     *d = av_expr_eval(e, const_values, opaque);

  609.     av_expr_free(e);

  610.     return isnan(*d) ? AVERROR(EINVAL) : 0;

  611. }

  612. 

  613. #if FF_API_OLD_EVAL_NAMES

  614. // LCOV_EXCL_START

  615. int av_parse_expr(AVExpr **expr, const char *s,

  616.                   const char * const *const_names,

  617.                   const char * const *func1_names, double (* const *funcs1)(void *, double),

  618.                   const char * const *func2_names, double (* const *funcs2)(void *, double, double),

  619.                   int log_offset, void *log_ctx)

  620. {

  621.     return av_expr_parse(expr, s, const_names, func1_names, funcs1, func2_names, funcs2,

  622.                       log_offset, log_ctx);

  623. }

  624. 

  625. double av_eval_expr(AVExpr *e, const double *const_values, void *opaque)

  626. {

  627.     return av_expr_eval(e, const_values, opaque);

  628. }

  629. 

  630. int av_parse_and_eval_expr(double *res, const char *s,

  631.                            const char * const *const_names, const double *const_values,

  632.                            const char * const *func1_names, double (* const *funcs1)(void *, double),

  633.                            const char * const *func2_names, double (* const *funcs2)(void *, double, double),

  634.                            void *opaque, int log_offset, void *log_ctx)

  635. {

  636.     return av_expr_parse_and_eval(res, s, const_names, const_values, func1_names, funcs1, func2_names, funcs2,

  637.                                   opaque, log_offset, log_ctx);

  638. }

  639. 

  640. void av_free_expr(AVExpr *e)

  641. {

  642.     av_expr_free(e);

  643. }

  644. // LCOV_EXCL_STOP

  645. #endif /* FF_API_OLD_EVAL_NAMES */

  646. 

  647. #ifdef TEST

  648. // LCOV_EXCL_START

  649. #undef printf

  650. #include <string.h>

  651. 

  652. static const double const_values[] = {

  653.     M_PI,

  654.     M_E,

  655.     0

  656. };

  657. 

  658. static const char *const const_names[] = {

  659.     "PI",

  660.     "E",

  661.     0

  662. };

  663. 

  664. int main(int argc, char **argv)

  665. {

  666.     int i;

  667.     double d;

  668.     const char **expr, *exprs[] = {

  669.         "",

  670.         "1;2",

  671.         "-20",

  672.         "-PI",

  673.         "+PI",

  674.         "1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)",

  675.         "80G/80Gi",

  676.         "1k",

  677.         "1Gi",

  678.         "1gi",

  679.         "1GiFoo",

  680.         "1k+1k",

  681.         "1Gi*3foo",

  682.         "foo",

  683.         "foo(",

  684.         "foo()",

  685.         "foo)",

  686.         "sin",

  687.         "sin(",

  688.         "sin()",

  689.         "sin)",

  690.         "sin 10",

  691.         "sin(1,2,3)",

  692.         "sin(1 )",

  693.         "1",

  694.         "1foo",

  695.         "bar + PI + E + 100f*2 + foo",

  696.         "13k + 12f - foo(1, 2)",

  697.         "1gi",

  698.         "1Gi",

  699.         "st(0, 123)",

  700.         "st(1, 123); ld(1)",

  701.         /* compute 1+2+...+N */

  702.         "st(0, 1); while(lte(ld(0), 100), st(1, ld(1)+ld(0));st(0, ld(0)+1)); ld(1)",

  703.         /* compute Fib(N) */

  704.         "st(1, 1); st(2, 2); st(0, 1); while(lte(ld(0),10), st(3, ld(1)+ld(2)); st(1, ld(2)); st(2, ld(3)); st(0, ld(0)+1)); ld(3)",

  705.         "while(0, 10)",

  706.         "st(0, 1); while(lte(ld(0),100), st(1, ld(1)+ld(0)); st(0, ld(0)+1))",

  707.         "isnan(1)",

  708.         "isnan(NAN)",

  709.         "floor(NAN)",

  710.         "floor(123.123)",

  711.         "floor(-123.123)",

  712.         "trunc(123.123)",

  713.         "trunc(-123.123)",

  714.         "ceil(123.123)",

  715.         "ceil(-123.123)",

  716.         "sqrt(1764)",

  717.         "isnan(sqrt(-1))",

  718.         "not(1)",

  719.         "not(NAN)",

  720.         "not(0)",

  721.         "pow(0,1.23)",

  722.         "pow(PI,1.23)",

  723.         "PI^1.23",

  724.         "pow(-1,1.23)",

  725.         "if(1, 2)",

  726.         "ifnot(0, 23)",

  727.         "ifnot(1, NaN) + if(0, 1)",

  728.         "taylor(1, 1)",

  729.         "taylor(eq(mod(ld(1),4),1)-eq(mod(ld(1),4),3), PI/2, 1)",

  730.         NULL

  731.     };

  732. 

  733.     for (expr = exprs; *expr; expr++) {

  734.         printf("Evaluating '%s'\n", *expr);

  735.         av_expr_parse_and_eval(&d, *expr,

  736.                                const_names, const_values,

  737.                                NULL, NULL, NULL, NULL, NULL, 0, NULL);

  738.         if(isnan(d)){

  739.             printf("'%s' -> nan\n\n", *expr);

  740.         }else{

  741.             printf("'%s' -> %f\n\n", *expr, d);

  742.         }

  743.     }

  744. 

  745.     av_expr_parse_and_eval(&d, "1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)",

  746.                            const_names, const_values,

  747.                            NULL, NULL, NULL, NULL, NULL, 0, NULL);

  748.     printf("%f == 12.7\n", d);

  749.     av_expr_parse_and_eval(&d, "80G/80Gi",

  750.                            const_names, const_values,

  751.                            NULL, NULL, NULL, NULL, NULL, 0, NULL);

  752.     printf("%f == 0.931322575\n", d);

  753. 

  754.     if (argc > 1 && !strcmp(argv[1], "-t")) {

  755.         for (i = 0; i < 1050; i++) {

  756.             START_TIMER;

  757.             av_expr_parse_and_eval(&d, "1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)",

  758.                                    const_names, const_values,

  759.                                    NULL, NULL, NULL, NULL, NULL, 0, NULL);

  760.             STOP_TIMER("av_expr_parse_and_eval");

  761.         }

  762.     }

  763. 

  764.     return 0;

  765. }

  766. // LCOV_EXCL_STOP

  767. #endif