FFmpeg: libavutil/eval.c Source File

00001 /*
00002  * Copyright (c) 2002-2006 Michael Niedermayer <michaelni@gmx.at>
00003  * Copyright (c) 2006 Oded Shimon <ods15@ods15.dyndns.org>
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00029 #include <float.h>
00030 #include "avutil.h"
00031 #include "eval.h"
00032 #include "log.h"
00033 
00034 typedef struct Parser {
00035     const AVClass *class;
00036     int stack_index;
00037     char *s;
00038     const double *const_values;
00039     const char * const *const_names;          // NULL terminated
00040     double (* const *funcs1)(void *, double a);           // NULL terminated
00041     const char * const *func1_names;          // NULL terminated
00042     double (* const *funcs2)(void *, double a, double b); // NULL terminated
00043     const char * const *func2_names;          // NULL terminated
00044     void *opaque;
00045     int log_offset;
00046     void *log_ctx;
00047 #define VARS 10
00048     double *var;
00049 } Parser;
00050 
00051 static const AVClass class = { "Eval", av_default_item_name, NULL, LIBAVUTIL_VERSION_INT, offsetof(Parser,log_offset), offsetof(Parser,log_ctx) };
00052 
00053 static const int8_t si_prefixes['z' - 'E' + 1] = {
00054     ['y'-'E']= -24,
00055     ['z'-'E']= -21,
00056     ['a'-'E']= -18,
00057     ['f'-'E']= -15,
00058     ['p'-'E']= -12,
00059     ['n'-'E']= - 9,
00060     ['u'-'E']= - 6,
00061     ['m'-'E']= - 3,
00062     ['c'-'E']= - 2,
00063     ['d'-'E']= - 1,
00064     ['h'-'E']=   2,
00065     ['k'-'E']=   3,
00066     ['K'-'E']=   3,
00067     ['M'-'E']=   6,
00068     ['G'-'E']=   9,
00069     ['T'-'E']=  12,
00070     ['P'-'E']=  15,
00071     ['E'-'E']=  18,
00072     ['Z'-'E']=  21,
00073     ['Y'-'E']=  24,
00074 };
00075 
00076 static const struct {
00077     const char *name;
00078     double value;
00079 } constants[] = {
00080     { "E",   M_E   },
00081     { "PI",  M_PI  },
00082     { "PHI", M_PHI },
00083 };
00084 
00085 double av_strtod(const char *numstr, char **tail)
00086 {
00087     double d;
00088     char *next;
00089     if(numstr[0]=='0' && (numstr[1]|0x20)=='x') {
00090         d = strtoul(numstr, &next, 16);
00091     } else
00092         d = strtod(numstr, &next);
00093     /* if parsing succeeded, check for and interpret postfixes */
00094     if (next!=numstr) {
00095         if (*next >= 'E' && *next <= 'z') {
00096             int e= si_prefixes[*next - 'E'];
00097             if (e) {
00098                 if (next[1] == 'i') {
00099                     d*= pow( 2, e/0.3);
00100                     next+=2;
00101                 } else {
00102                     d*= pow(10, e);
00103                     next++;
00104                 }
00105             }
00106         }
00107 
00108         if (*next=='B') {
00109             d*=8;
00110             next++;
00111         }
00112     }
00113     /* if requested, fill in tail with the position after the last parsed
00114        character */
00115     if (tail)
00116         *tail = next;
00117     return d;
00118 }
00119 
00120 #define IS_IDENTIFIER_CHAR(c) ((c) - '0' <= 9U || (c) - 'a' <= 25U || (c) - 'A' <= 25U || (c) == '_')
00121 
00122 static int strmatch(const char *s, const char *prefix)
00123 {
00124     int i;
00125     for (i=0; prefix[i]; i++) {
00126         if (prefix[i] != s[i]) return 0;
00127     }
00128     /* return 1 only if the s identifier is terminated */
00129     return !IS_IDENTIFIER_CHAR(s[i]);
00130 }
00131 
00132 struct AVExpr {
00133     enum {
00134         e_value, e_const, e_func0, e_func1, e_func2,
00135         e_squish, e_gauss, e_ld, e_isnan,
00136         e_mod, e_max, e_min, e_eq, e_gt, e_gte,
00137         e_pow, e_mul, e_div, e_add,
00138         e_last, e_st, e_while, e_taylor, e_root, e_floor, e_ceil, e_trunc,
00139         e_sqrt, e_not, e_random, e_hypot, e_gcd,
00140         e_if, e_ifnot,
00141     } type;
00142     double value; // is sign in other types
00143     union {
00144         int const_index;
00145         double (*func0)(double);
00146         double (*func1)(void *, double);
00147         double (*func2)(void *, double, double);
00148     } a;
00149     struct AVExpr *param[3];
00150     double *var;
00151 };
00152 
00153 static double eval_expr(Parser *p, AVExpr *e)
00154 {
00155     switch (e->type) {
00156         case e_value:  return e->value;
00157         case e_const:  return e->value * p->const_values[e->a.const_index];
00158         case e_func0:  return e->value * e->a.func0(eval_expr(p, e->param[0]));
00159         case e_func1:  return e->value * e->a.func1(p->opaque, eval_expr(p, e->param[0]));
00160         case e_func2:  return e->value * e->a.func2(p->opaque, eval_expr(p, e->param[0]), eval_expr(p, e->param[1]));
00161         case e_squish: return 1/(1+exp(4*eval_expr(p, e->param[0])));
00162         case e_gauss: { double d = eval_expr(p, e->param[0]); return exp(-d*d/2)/sqrt(2*M_PI); }
00163         case e_ld:     return e->value * p->var[av_clip(eval_expr(p, e->param[0]), 0, VARS-1)];
00164         case e_isnan:  return e->value * !!isnan(eval_expr(p, e->param[0]));
00165         case e_floor:  return e->value * floor(eval_expr(p, e->param[0]));
00166         case e_ceil :  return e->value * ceil (eval_expr(p, e->param[0]));
00167         case e_trunc:  return e->value * trunc(eval_expr(p, e->param[0]));
00168         case e_sqrt:   return e->value * sqrt (eval_expr(p, e->param[0]));
00169         case e_not:    return e->value * (eval_expr(p, e->param[0]) == 0);
00170         case e_if:     return e->value * ( eval_expr(p, e->param[0]) ? eval_expr(p, e->param[1]) : 0);
00171         case e_ifnot:  return e->value * (!eval_expr(p, e->param[0]) ? eval_expr(p, e->param[1]) : 0);
00172         case e_random:{
00173             int idx= av_clip(eval_expr(p, e->param[0]), 0, VARS-1);
00174             uint64_t r= isnan(p->var[idx]) ? 0 : p->var[idx];
00175             r= r*1664525+1013904223;
00176             p->var[idx]= r;
00177             return e->value * (r * (1.0/UINT64_MAX));
00178         }
00179         case e_while: {
00180             double d = NAN;
00181             while (eval_expr(p, e->param[0]))
00182                 d=eval_expr(p, e->param[1]);
00183             return d;
00184         }
00185         case e_taylor: {
00186             double t = 1, d = 0, v;
00187             double x = eval_expr(p, e->param[1]);
00188             int id = e->param[2] ? av_clip(eval_expr(p, e->param[2]), 0, VARS-1) : 0;
00189             int i;
00190             double var0 = p->var[id];
00191             for(i=0; i<1000; i++) {
00192                 double ld = d;
00193                 p->var[id] = i;
00194                 v = eval_expr(p, e->param[0]);
00195                 d += t*v;
00196                 if(ld==d && v)
00197                     break;
00198                 t *= x / (i+1);
00199             }
00200             p->var[id] = var0;
00201             return d;
00202         }
00203         case e_root: {
00204             int i, j;
00205             double low = -1, high = -1, v, low_v = -DBL_MAX, high_v = DBL_MAX;
00206             double var0 = p->var[0];
00207             double x_max = eval_expr(p, e->param[1]);
00208             for(i=-1; i<1024; i++) {
00209                 if(i<255) {
00210                     p->var[0] = av_reverse[i&255]*x_max/255;
00211                 } else {
00212                     p->var[0] = x_max*pow(0.9, i-255);
00213                     if (i&1) p->var[0] *= -1;
00214                     if (i&2) p->var[0] += low;
00215                     else     p->var[0] += high;
00216                 }
00217                 v = eval_expr(p, e->param[0]);
00218                 if (v<=0 && v>low_v) {
00219                     low    = p->var[0];
00220                     low_v  = v;
00221                 }
00222                 if (v>=0 && v<high_v) {
00223                     high   = p->var[0];
00224                     high_v = v;
00225                 }
00226                 if (low>=0 && high>=0){
00227                     for (j=0; j<1000; j++) {
00228                         p->var[0] = (low+high)*0.5;
00229                         if (low == p->var[0] || high == p->var[0])
00230                             break;
00231                         v = eval_expr(p, e->param[0]);
00232                         if (v<=0) low = p->var[0];
00233                         if (v>=0) high= p->var[0];
00234                         if (isnan(v)) {
00235                             low = high = v;
00236                             break;
00237                         }
00238                     }
00239                     break;
00240                 }
00241             }
00242             p->var[0] = var0;
00243             return -low_v<high_v ? low : high;
00244         }
00245         default: {
00246             double d = eval_expr(p, e->param[0]);
00247             double d2 = eval_expr(p, e->param[1]);
00248             switch (e->type) {
00249                 case e_mod: return e->value * (d - floor(d/d2)*d2);
00250                 case e_gcd: return e->value * av_gcd(d,d2);
00251                 case e_max: return e->value * (d >  d2 ?   d : d2);
00252                 case e_min: return e->value * (d <  d2 ?   d : d2);
00253                 case e_eq:  return e->value * (d == d2 ? 1.0 : 0.0);
00254                 case e_gt:  return e->value * (d >  d2 ? 1.0 : 0.0);
00255                 case e_gte: return e->value * (d >= d2 ? 1.0 : 0.0);
00256                 case e_pow: return e->value * pow(d, d2);
00257                 case e_mul: return e->value * (d * d2);
00258                 case e_div: return e->value * (d / d2);
00259                 case e_add: return e->value * (d + d2);
00260                 case e_last:return e->value * d2;
00261                 case e_st : return e->value * (p->var[av_clip(d, 0, VARS-1)]= d2);
00262                 case e_hypot:return e->value * (sqrt(d*d + d2*d2));
00263             }
00264         }
00265     }
00266     return NAN;
00267 }
00268 
00269 static int parse_expr(AVExpr **e, Parser *p);
00270 
00271 void av_expr_free(AVExpr *e)
00272 {
00273     if (!e) return;
00274     av_expr_free(e->param[0]);
00275     av_expr_free(e->param[1]);
00276     av_expr_free(e->param[2]);
00277     av_freep(&e->var);
00278     av_freep(&e);
00279 }
00280 
00281 static int parse_primary(AVExpr **e, Parser *p)
00282 {
00283     AVExpr *d = av_mallocz(sizeof(AVExpr));
00284     char *next = p->s, *s0 = p->s;
00285     int ret, i;
00286 
00287     if (!d)
00288         return AVERROR(ENOMEM);
00289 
00290     /* number */
00291     d->value = av_strtod(p->s, &next);
00292     if (next != p->s) {
00293         d->type = e_value;
00294         p->s= next;
00295         *e = d;
00296         return 0;
00297     }
00298     d->value = 1;
00299 
00300     /* named constants */
00301     for (i=0; p->const_names && p->const_names[i]; i++) {
00302         if (strmatch(p->s, p->const_names[i])) {
00303             p->s+= strlen(p->const_names[i]);
00304             d->type = e_const;
00305             d->a.const_index = i;
00306             *e = d;
00307             return 0;
00308         }
00309     }
00310     for (i = 0; i < FF_ARRAY_ELEMS(constants); i++) {
00311         if (strmatch(p->s, constants[i].name)) {
00312             p->s += strlen(constants[i].name);
00313             d->type = e_value;
00314             d->value = constants[i].value;
00315             *e = d;
00316             return 0;
00317         }
00318     }
00319 
00320     p->s= strchr(p->s, '(');
00321     if (p->s==NULL) {
00322         av_log(p, AV_LOG_ERROR, "Undefined constant or missing '(' in '%s'\n", s0);
00323         p->s= next;
00324         av_expr_free(d);
00325         return AVERROR(EINVAL);
00326     }
00327     p->s++; // "("
00328     if (*next == '(') { // special case do-nothing
00329         av_freep(&d);
00330         if ((ret = parse_expr(&d, p)) < 0)
00331             return ret;
00332         if (p->s[0] != ')') {
00333             av_log(p, AV_LOG_ERROR, "Missing ')' in '%s'\n", s0);
00334             av_expr_free(d);
00335             return AVERROR(EINVAL);
00336         }
00337         p->s++; // ")"
00338         *e = d;
00339         return 0;
00340     }
00341     if ((ret = parse_expr(&(d->param[0]), p)) < 0) {
00342         av_expr_free(d);
00343         return ret;
00344     }
00345     if (p->s[0]== ',') {
00346         p->s++; // ","
00347         parse_expr(&d->param[1], p);
00348     }
00349     if (p->s[0]== ',') {
00350         p->s++; // ","
00351         parse_expr(&d->param[2], p);
00352     }
00353     if (p->s[0] != ')') {
00354         av_log(p, AV_LOG_ERROR, "Missing ')' or too many args in '%s'\n", s0);
00355         av_expr_free(d);
00356         return AVERROR(EINVAL);
00357     }
00358     p->s++; // ")"
00359 
00360     d->type = e_func0;
00361          if (strmatch(next, "sinh"  )) d->a.func0 = sinh;
00362     else if (strmatch(next, "cosh"  )) d->a.func0 = cosh;
00363     else if (strmatch(next, "tanh"  )) d->a.func0 = tanh;
00364     else if (strmatch(next, "sin"   )) d->a.func0 = sin;
00365     else if (strmatch(next, "cos"   )) d->a.func0 = cos;
00366     else if (strmatch(next, "tan"   )) d->a.func0 = tan;
00367     else if (strmatch(next, "atan"  )) d->a.func0 = atan;
00368     else if (strmatch(next, "asin"  )) d->a.func0 = asin;
00369     else if (strmatch(next, "acos"  )) d->a.func0 = acos;
00370     else if (strmatch(next, "exp"   )) d->a.func0 = exp;
00371     else if (strmatch(next, "log"   )) d->a.func0 = log;
00372     else if (strmatch(next, "abs"   )) d->a.func0 = fabs;
00373     else if (strmatch(next, "squish")) d->type = e_squish;
00374     else if (strmatch(next, "gauss" )) d->type = e_gauss;
00375     else if (strmatch(next, "mod"   )) d->type = e_mod;
00376     else if (strmatch(next, "max"   )) d->type = e_max;
00377     else if (strmatch(next, "min"   )) d->type = e_min;
00378     else if (strmatch(next, "eq"    )) d->type = e_eq;
00379     else if (strmatch(next, "gte"   )) d->type = e_gte;
00380     else if (strmatch(next, "gt"    )) d->type = e_gt;
00381     else if (strmatch(next, "lte"   )) { AVExpr *tmp = d->param[1]; d->param[1] = d->param[0]; d->param[0] = tmp; d->type = e_gte; }
00382     else if (strmatch(next, "lt"    )) { AVExpr *tmp = d->param[1]; d->param[1] = d->param[0]; d->param[0] = tmp; d->type = e_gt; }
00383     else if (strmatch(next, "ld"    )) d->type = e_ld;
00384     else if (strmatch(next, "isnan" )) d->type = e_isnan;
00385     else if (strmatch(next, "st"    )) d->type = e_st;
00386     else if (strmatch(next, "while" )) d->type = e_while;
00387     else if (strmatch(next, "taylor")) d->type = e_taylor;
00388     else if (strmatch(next, "root"  )) d->type = e_root;
00389     else if (strmatch(next, "floor" )) d->type = e_floor;
00390     else if (strmatch(next, "ceil"  )) d->type = e_ceil;
00391     else if (strmatch(next, "trunc" )) d->type = e_trunc;
00392     else if (strmatch(next, "sqrt"  )) d->type = e_sqrt;
00393     else if (strmatch(next, "not"   )) d->type = e_not;
00394     else if (strmatch(next, "pow"   )) d->type = e_pow;
00395     else if (strmatch(next, "random")) d->type = e_random;
00396     else if (strmatch(next, "hypot" )) d->type = e_hypot;
00397     else if (strmatch(next, "gcd"   )) d->type = e_gcd;
00398     else if (strmatch(next, "if"    )) d->type = e_if;
00399     else if (strmatch(next, "ifnot" )) d->type = e_ifnot;
00400     else {
00401         for (i=0; p->func1_names && p->func1_names[i]; i++) {
00402             if (strmatch(next, p->func1_names[i])) {
00403                 d->a.func1 = p->funcs1[i];
00404                 d->type = e_func1;
00405                 *e = d;
00406                 return 0;
00407             }
00408         }
00409 
00410         for (i=0; p->func2_names && p->func2_names[i]; i++) {
00411             if (strmatch(next, p->func2_names[i])) {
00412                 d->a.func2 = p->funcs2[i];
00413                 d->type = e_func2;
00414                 *e = d;
00415                 return 0;
00416             }
00417         }
00418 
00419         av_log(p, AV_LOG_ERROR, "Unknown function in '%s'\n", s0);
00420         av_expr_free(d);
00421         return AVERROR(EINVAL);
00422     }
00423 
00424     *e = d;
00425     return 0;
00426 }
00427 
00428 static AVExpr *new_eval_expr(int type, int value, AVExpr *p0, AVExpr *p1)
00429 {
00430     AVExpr *e = av_mallocz(sizeof(AVExpr));
00431     if (!e)
00432         return NULL;
00433     e->type     =type   ;
00434     e->value    =value  ;
00435     e->param[0] =p0     ;
00436     e->param[1] =p1     ;
00437     return e;
00438 }
00439 
00440 static int parse_pow(AVExpr **e, Parser *p, int *sign)
00441 {
00442     *sign= (*p->s == '+') - (*p->s == '-');
00443     p->s += *sign&1;
00444     return parse_primary(e, p);
00445 }
00446 
00447 static int parse_factor(AVExpr **e, Parser *p)
00448 {
00449     int sign, sign2, ret;
00450     AVExpr *e0, *e1, *e2;
00451     if ((ret = parse_pow(&e0, p, &sign)) < 0)
00452         return ret;
00453     while(p->s[0]=='^'){
00454         e1 = e0;
00455         p->s++;
00456         if ((ret = parse_pow(&e2, p, &sign2)) < 0) {
00457             av_expr_free(e1);
00458             return ret;
00459         }
00460         e0 = new_eval_expr(e_pow, 1, e1, e2);
00461         if (!e0) {
00462             av_expr_free(e1);
00463             av_expr_free(e2);
00464             return AVERROR(ENOMEM);
00465         }
00466         if (e0->param[1]) e0->param[1]->value *= (sign2|1);
00467     }
00468     if (e0) e0->value *= (sign|1);
00469 
00470     *e = e0;
00471     return 0;
00472 }
00473 
00474 static int parse_term(AVExpr **e, Parser *p)
00475 {
00476     int ret;
00477     AVExpr *e0, *e1, *e2;
00478     if ((ret = parse_factor(&e0, p)) < 0)
00479         return ret;
00480     while (p->s[0]=='*' || p->s[0]=='/') {
00481         int c= *p->s++;
00482         e1 = e0;
00483         if ((ret = parse_factor(&e2, p)) < 0) {
00484             av_expr_free(e1);
00485             return ret;
00486         }
00487         e0 = new_eval_expr(c == '*' ? e_mul : e_div, 1, e1, e2);
00488         if (!e0) {
00489             av_expr_free(e1);
00490             av_expr_free(e2);
00491             return AVERROR(ENOMEM);
00492         }
00493     }
00494     *e = e0;
00495     return 0;
00496 }
00497 
00498 static int parse_subexpr(AVExpr **e, Parser *p)
00499 {
00500     int ret;
00501     AVExpr *e0, *e1, *e2;
00502     if ((ret = parse_term(&e0, p)) < 0)
00503         return ret;
00504     while (*p->s == '+' || *p->s == '-') {
00505         e1 = e0;
00506         if ((ret = parse_term(&e2, p)) < 0) {
00507             av_expr_free(e1);
00508             return ret;
00509         }
00510         e0 = new_eval_expr(e_add, 1, e1, e2);
00511         if (!e0) {
00512             av_expr_free(e1);
00513             av_expr_free(e2);
00514             return AVERROR(ENOMEM);
00515         }
00516     };
00517 
00518     *e = e0;
00519     return 0;
00520 }
00521 
00522 static int parse_expr(AVExpr **e, Parser *p)
00523 {
00524     int ret;
00525     AVExpr *e0, *e1, *e2;
00526     if (p->stack_index <= 0) //protect against stack overflows
00527         return AVERROR(EINVAL);
00528     p->stack_index--;
00529 
00530     if ((ret = parse_subexpr(&e0, p)) < 0)
00531         return ret;
00532     while (*p->s == ';') {
00533         p->s++;
00534         e1 = e0;
00535         if ((ret = parse_subexpr(&e2, p)) < 0) {
00536             av_expr_free(e1);
00537             return ret;
00538         }
00539         e0 = new_eval_expr(e_last, 1, e1, e2);
00540         if (!e0) {
00541             av_expr_free(e1);
00542             av_expr_free(e2);
00543             return AVERROR(ENOMEM);
00544         }
00545     };
00546 
00547     p->stack_index++;
00548     *e = e0;
00549     return 0;
00550 }
00551 
00552 static int verify_expr(AVExpr *e)
00553 {
00554     if (!e) return 0;
00555     switch (e->type) {
00556         case e_value:
00557         case e_const: return 1;
00558         case e_func0:
00559         case e_func1:
00560         case e_squish:
00561         case e_ld:
00562         case e_gauss:
00563         case e_isnan:
00564         case e_floor:
00565         case e_ceil:
00566         case e_trunc:
00567         case e_sqrt:
00568         case e_not:
00569         case e_random:
00570             return verify_expr(e->param[0]) && !e->param[1];
00571         case e_taylor:
00572             return verify_expr(e->param[0]) && verify_expr(e->param[1])
00573                    && (!e->param[2] || verify_expr(e->param[2]));
00574         default: return verify_expr(e->param[0]) && verify_expr(e->param[1]) && !e->param[2];
00575     }
00576 }
00577 
00578 int av_expr_parse(AVExpr **expr, const char *s,
00579                   const char * const *const_names,
00580                   const char * const *func1_names, double (* const *funcs1)(void *, double),
00581                   const char * const *func2_names, double (* const *funcs2)(void *, double, double),
00582                   int log_offset, void *log_ctx)
00583 {
00584     Parser p = { 0 };
00585     AVExpr *e = NULL;
00586     char *w = av_malloc(strlen(s) + 1);
00587     char *wp = w;
00588     const char *s0 = s;
00589     int ret = 0;
00590 
00591     if (!w)
00592         return AVERROR(ENOMEM);
00593 
00594     while (*s)
00595         if (!isspace(*s++)) *wp++ = s[-1];
00596     *wp++ = 0;
00597 
00598     p.class      = &class;
00599     p.stack_index=100;
00600     p.s= w;
00601     p.const_names = const_names;
00602     p.funcs1      = funcs1;
00603     p.func1_names = func1_names;
00604     p.funcs2      = funcs2;
00605     p.func2_names = func2_names;
00606     p.log_offset = log_offset;
00607     p.log_ctx    = log_ctx;
00608 
00609     if ((ret = parse_expr(&e, &p)) < 0)
00610         goto end;
00611     if (*p.s) {
00612         av_expr_free(e);
00613         av_log(&p, AV_LOG_ERROR, "Invalid chars '%s' at the end of expression '%s'\n", p.s, s0);
00614         ret = AVERROR(EINVAL);
00615         goto end;
00616     }
00617     if (!verify_expr(e)) {
00618         av_expr_free(e);
00619         ret = AVERROR(EINVAL);
00620         goto end;
00621     }
00622     e->var= av_mallocz(sizeof(double) *VARS);
00623     *expr = e;
00624 end:
00625     av_free(w);
00626     return ret;
00627 }
00628 
00629 double av_expr_eval(AVExpr *e, const double *const_values, void *opaque)
00630 {
00631     Parser p = { 0 };
00632     p.var= e->var;
00633 
00634     p.const_values = const_values;
00635     p.opaque     = opaque;
00636     return eval_expr(&p, e);
00637 }
00638 
00639 int av_expr_parse_and_eval(double *d, const char *s,
00640                            const char * const *const_names, const double *const_values,
00641                            const char * const *func1_names, double (* const *funcs1)(void *, double),
00642                            const char * const *func2_names, double (* const *funcs2)(void *, double, double),
00643                            void *opaque, int log_offset, void *log_ctx)
00644 {
00645     AVExpr *e = NULL;
00646     int ret = av_expr_parse(&e, s, const_names, func1_names, funcs1, func2_names, funcs2, log_offset, log_ctx);
00647 
00648     if (ret < 0) {
00649         *d = NAN;
00650         return ret;
00651     }
00652     *d = av_expr_eval(e, const_values, opaque);
00653     av_expr_free(e);
00654     return isnan(*d) ? AVERROR(EINVAL) : 0;
00655 }
00656 
00657 #if FF_API_OLD_EVAL_NAMES
00658 // LCOV_EXCL_START
00659 int av_parse_expr(AVExpr **expr, const char *s,
00660                   const char * const *const_names,
00661                   const char * const *func1_names, double (* const *funcs1)(void *, double),
00662                   const char * const *func2_names, double (* const *funcs2)(void *, double, double),
00663                   int log_offset, void *log_ctx)
00664 {
00665     return av_expr_parse(expr, s, const_names, func1_names, funcs1, func2_names, funcs2,
00666                       log_offset, log_ctx);
00667 }
00668 
00669 double av_eval_expr(AVExpr *e, const double *const_values, void *opaque)
00670 {
00671     return av_expr_eval(e, const_values, opaque);
00672 }
00673 
00674 int av_parse_and_eval_expr(double *res, const char *s,
00675                            const char * const *const_names, const double *const_values,
00676                            const char * const *func1_names, double (* const *funcs1)(void *, double),
00677                            const char * const *func2_names, double (* const *funcs2)(void *, double, double),
00678                            void *opaque, int log_offset, void *log_ctx)
00679 {
00680     return av_expr_parse_and_eval(res, s, const_names, const_values, func1_names, funcs1, func2_names, funcs2,
00681                                   opaque, log_offset, log_ctx);
00682 }
00683 
00684 void av_free_expr(AVExpr *e)
00685 {
00686     av_expr_free(e);
00687 }
00688 // LCOV_EXCL_STOP
00689 #endif /* FF_API_OLD_EVAL_NAMES */
00690 
00691 #ifdef TEST
00692 // LCOV_EXCL_START
00693 #undef printf
00694 #include <string.h>
00695 
00696 static const double const_values[] = {
00697     M_PI,
00698     M_E,
00699     0
00700 };
00701 
00702 static const char *const const_names[] = {
00703     "PI",
00704     "E",
00705     0
00706 };
00707 
00708 int main(int argc, char **argv)
00709 {
00710     int i;
00711     double d;
00712     const char **expr, *exprs[] = {
00713         "",
00714         "1;2",
00715         "-20",
00716         "-PI",
00717         "+PI",
00718         "1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)",
00719         "80G/80Gi",
00720         "1k",
00721         "1Gi",
00722         "1gi",
00723         "1GiFoo",
00724         "1k+1k",
00725         "1Gi*3foo",
00726         "foo",
00727         "foo(",
00728         "foo()",
00729         "foo)",
00730         "sin",
00731         "sin(",
00732         "sin()",
00733         "sin)",
00734         "sin 10",
00735         "sin(1,2,3)",
00736         "sin(1 )",
00737         "1",
00738         "1foo",
00739         "bar + PI + E + 100f*2 + foo",
00740         "13k + 12f - foo(1, 2)",
00741         "1gi",
00742         "1Gi",
00743         "st(0, 123)",
00744         "st(1, 123); ld(1)",
00745         /* compute 1+2+...+N */
00746         "st(0, 1); while(lte(ld(0), 100), st(1, ld(1)+ld(0));st(0, ld(0)+1)); ld(1)",
00747         /* compute Fib(N) */
00748         "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)",
00749         "while(0, 10)",
00750         "st(0, 1); while(lte(ld(0),100), st(1, ld(1)+ld(0)); st(0, ld(0)+1))",
00751         "isnan(1)",
00752         "isnan(NAN)",
00753         "floor(NAN)",
00754         "floor(123.123)",
00755         "floor(-123.123)",
00756         "trunc(123.123)",
00757         "trunc(-123.123)",
00758         "ceil(123.123)",
00759         "ceil(-123.123)",
00760         "sqrt(1764)",
00761         "isnan(sqrt(-1))",
00762         "not(1)",
00763         "not(NAN)",
00764         "not(0)",
00765         "pow(0,1.23)",
00766         "pow(PI,1.23)",
00767         "PI^1.23",
00768         "pow(-1,1.23)",
00769         "if(1, 2)",
00770         "ifnot(0, 23)",
00771         "ifnot(1, NaN) + if(0, 1)",
00772         "taylor(1, 1)",
00773         "taylor(eq(mod(ld(1),4),1)-eq(mod(ld(1),4),3), PI/2, 1)",
00774         "root(sin(ld(0))-1, 2)",
00775         "root(sin(ld(0))+6+sin(ld(0)/12)-log(ld(0)), 100)",
00776         NULL
00777     };
00778 
00779     for (expr = exprs; *expr; expr++) {
00780         printf("Evaluating '%s'\n", *expr);
00781         av_expr_parse_and_eval(&d, *expr,
00782                                const_names, const_values,
00783                                NULL, NULL, NULL, NULL, NULL, 0, NULL);
00784         if(isnan(d)){
00785             printf("'%s' -> nan\n\n", *expr);
00786         }else{
00787             printf("'%s' -> %f\n\n", *expr, d);
00788         }
00789     }
00790 
00791     av_expr_parse_and_eval(&d, "1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)",
00792                            const_names, const_values,
00793                            NULL, NULL, NULL, NULL, NULL, 0, NULL);
00794     printf("%f == 12.7\n", d);
00795     av_expr_parse_and_eval(&d, "80G/80Gi",
00796                            const_names, const_values,
00797                            NULL, NULL, NULL, NULL, NULL, 0, NULL);
00798     printf("%f == 0.931322575\n", d);
00799 
00800     if (argc > 1 && !strcmp(argv[1], "-t")) {
00801         for (i = 0; i < 1050; i++) {
00802             START_TIMER;
00803             av_expr_parse_and_eval(&d, "1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)",
00804                                    const_names, const_values,
00805                                    NULL, NULL, NULL, NULL, NULL, 0, NULL);
00806             STOP_TIMER("av_expr_parse_and_eval");
00807         }
00808     }
00809 
00810     return 0;
00811 }
00812 // LCOV_EXCL_STOP
00813 #endif