| 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 <float.h> |
| 30 | #include "attributes.h" |
| 31 | #include "avutil.h" |
| 32 | #include "common.h" |
| 33 | #include "eval.h" |
| 34 | #include "log.h" |
| 35 | #include "mathematics.h" |
| 36 | #include "time.h" |
| 37 | #include "avstring.h" |
| 38 | #include "timer.h" |
| 39 | |
| 40 | typedef struct Parser { |
| 41 | const AVClass *class; |
| 42 | int stack_index; |
| 43 | char *s; |
| 44 | const double *const_values; |
| 45 | const char * const *const_names; // NULL terminated |
| 46 | double (* const *funcs1)(void *, double a); // NULL terminated |
| 47 | const char * const *func1_names; // NULL terminated |
| 48 | double (* const *funcs2)(void *, double a, double b); // NULL terminated |
| 49 | const char * const *func2_names; // NULL terminated |
| 50 | void *opaque; |
| 51 | int log_offset; |
| 52 | void *log_ctx; |
| 53 | #define VARS 10 |
| 54 | double *var; |
| 55 | } Parser; |
| 56 | |
| 57 | static const AVClass eval_class = { "Eval", av_default_item_name, NULL, LIBAVUTIL_VERSION_INT, offsetof(Parser,log_offset), offsetof(Parser,log_ctx) }; |
| 58 | |
| 59 | static const int8_t si_prefixes['z' - 'E' + 1] = { |
| 60 | ['y'-'E']= -24, |
| 61 | ['z'-'E']= -21, |
| 62 | ['a'-'E']= -18, |
| 63 | ['f'-'E']= -15, |
| 64 | ['p'-'E']= -12, |
| 65 | ['n'-'E']= - 9, |
| 66 | ['u'-'E']= - 6, |
| 67 | ['m'-'E']= - 3, |
| 68 | ['c'-'E']= - 2, |
| 69 | ['d'-'E']= - 1, |
| 70 | ['h'-'E']= 2, |
| 71 | ['k'-'E']= 3, |
| 72 | ['K'-'E']= 3, |
| 73 | ['M'-'E']= 6, |
| 74 | ['G'-'E']= 9, |
| 75 | ['T'-'E']= 12, |
| 76 | ['P'-'E']= 15, |
| 77 | ['E'-'E']= 18, |
| 78 | ['Z'-'E']= 21, |
| 79 | ['Y'-'E']= 24, |
| 80 | }; |
| 81 | |
| 82 | static const struct { |
| 83 | const char *name; |
| 84 | double value; |
| 85 | } constants[] = { |
| 86 | { "E", M_E }, |
| 87 | { "PI", M_PI }, |
| 88 | { "PHI", M_PHI }, |
| 89 | { "QP2LAMBDA", FF_QP2LAMBDA }, |
| 90 | }; |
| 91 | |
| 92 | double av_strtod(const char *numstr, char **tail) |
| 93 | { |
| 94 | double d; |
| 95 | char *next; |
| 96 | if(numstr[0]=='0' && (numstr[1]|0x20)=='x') { |
| 97 | d = strtoul(numstr, &next, 16); |
| 98 | } else |
| 99 | d = strtod(numstr, &next); |
| 100 | /* if parsing succeeded, check for and interpret postfixes */ |
| 101 | if (next!=numstr) { |
| 102 | if (next[0] == 'd' && next[1] == 'B') { |
| 103 | /* treat dB as decibels instead of decibytes */ |
| 104 | d = pow(10, d / 20); |
| 105 | next += 2; |
| 106 | } else if (*next >= 'E' && *next <= 'z') { |
| 107 | int e= si_prefixes[*next - 'E']; |
| 108 | if (e) { |
| 109 | if (next[1] == 'i') { |
| 110 | d*= pow( 2, e/0.3); |
| 111 | next+=2; |
| 112 | } else { |
| 113 | d*= pow(10, e); |
| 114 | next++; |
| 115 | } |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | if (*next=='B') { |
| 120 | d*=8; |
| 121 | next++; |
| 122 | } |
| 123 | } |
| 124 | /* if requested, fill in tail with the position after the last parsed |
| 125 | character */ |
| 126 | if (tail) |
| 127 | *tail = next; |
| 128 | return d; |
| 129 | } |
| 130 | |
| 131 | #define IS_IDENTIFIER_CHAR(c) ((c) - '0' <= 9U || (c) - 'a' <= 25U || (c) - 'A' <= 25U || (c) == '_') |
| 132 | |
| 133 | static int strmatch(const char *s, const char *prefix) |
| 134 | { |
| 135 | int i; |
| 136 | for (i=0; prefix[i]; i++) { |
| 137 | if (prefix[i] != s[i]) return 0; |
| 138 | } |
| 139 | /* return 1 only if the s identifier is terminated */ |
| 140 | return !IS_IDENTIFIER_CHAR(s[i]); |
| 141 | } |
| 142 | |
| 143 | struct AVExpr { |
| 144 | enum { |
| 145 | e_value, e_const, e_func0, e_func1, e_func2, |
| 146 | e_squish, e_gauss, e_ld, e_isnan, e_isinf, |
| 147 | e_mod, e_max, e_min, e_eq, e_gt, e_gte, e_lte, e_lt, |
| 148 | e_pow, e_mul, e_div, e_add, |
| 149 | e_last, e_st, e_while, e_taylor, e_root, e_floor, e_ceil, e_trunc, |
| 150 | e_sqrt, e_not, e_random, e_hypot, e_gcd, |
| 151 | e_if, e_ifnot, e_print, e_bitand, e_bitor, e_between, e_clip |
| 152 | } type; |
| 153 | double value; // is sign in other types |
| 154 | union { |
| 155 | int const_index; |
| 156 | double (*func0)(double); |
| 157 | double (*func1)(void *, double); |
| 158 | double (*func2)(void *, double, double); |
| 159 | } a; |
| 160 | struct AVExpr *param[3]; |
| 161 | double *var; |
| 162 | }; |
| 163 | |
| 164 | static double etime(double v) |
| 165 | { |
| 166 | return av_gettime() * 0.000001; |
| 167 | } |
| 168 | |
| 169 | static double eval_expr(Parser *p, AVExpr *e) |
| 170 | { |
| 171 | switch (e->type) { |
| 172 | case e_value: return e->value; |
| 173 | case e_const: return e->value * p->const_values[e->a.const_index]; |
| 174 | case e_func0: return e->value * e->a.func0(eval_expr(p, e->param[0])); |
| 175 | case e_func1: return e->value * e->a.func1(p->opaque, eval_expr(p, e->param[0])); |
| 176 | case e_func2: return e->value * e->a.func2(p->opaque, eval_expr(p, e->param[0]), eval_expr(p, e->param[1])); |
| 177 | case e_squish: return 1/(1+exp(4*eval_expr(p, e->param[0]))); |
| 178 | case e_gauss: { double d = eval_expr(p, e->param[0]); return exp(-d*d/2)/sqrt(2*M_PI); } |
| 179 | case e_ld: return e->value * p->var[av_clip(eval_expr(p, e->param[0]), 0, VARS-1)]; |
| 180 | case e_isnan: return e->value * !!isnan(eval_expr(p, e->param[0])); |
| 181 | case e_isinf: return e->value * !!isinf(eval_expr(p, e->param[0])); |
| 182 | case e_floor: return e->value * floor(eval_expr(p, e->param[0])); |
| 183 | case e_ceil : return e->value * ceil (eval_expr(p, e->param[0])); |
| 184 | case e_trunc: return e->value * trunc(eval_expr(p, e->param[0])); |
| 185 | case e_sqrt: return e->value * sqrt (eval_expr(p, e->param[0])); |
| 186 | case e_not: return e->value * (eval_expr(p, e->param[0]) == 0); |
| 187 | case e_if: return e->value * (eval_expr(p, e->param[0]) ? eval_expr(p, e->param[1]) : |
| 188 | e->param[2] ? eval_expr(p, e->param[2]) : 0); |
| 189 | case e_ifnot: return e->value * (!eval_expr(p, e->param[0]) ? eval_expr(p, e->param[1]) : |
| 190 | e->param[2] ? eval_expr(p, e->param[2]) : 0); |
| 191 | case e_clip: { |
| 192 | double x = eval_expr(p, e->param[0]); |
| 193 | double min = eval_expr(p, e->param[1]), max = eval_expr(p, e->param[2]); |
| 194 | if (isnan(min) || isnan(max) || isnan(x) || min > max) |
| 195 | return NAN; |
| 196 | return e->value * av_clipd(eval_expr(p, e->param[0]), min, max); |
| 197 | } |
| 198 | case e_between: { |
| 199 | double d = eval_expr(p, e->param[0]); |
| 200 | return e->value * (d >= eval_expr(p, e->param[1]) && |
| 201 | d <= eval_expr(p, e->param[2])); |
| 202 | } |
| 203 | case e_print: { |
| 204 | double x = eval_expr(p, e->param[0]); |
| 205 | int level = e->param[1] ? av_clip(eval_expr(p, e->param[1]), INT_MIN, INT_MAX) : AV_LOG_INFO; |
| 206 | av_log(p, level, "%f\n", x); |
| 207 | return x; |
| 208 | } |
| 209 | case e_random:{ |
| 210 | int idx= av_clip(eval_expr(p, e->param[0]), 0, VARS-1); |
| 211 | uint64_t r= isnan(p->var[idx]) ? 0 : p->var[idx]; |
| 212 | r= r*1664525+1013904223; |
| 213 | p->var[idx]= r; |
| 214 | return e->value * (r * (1.0/UINT64_MAX)); |
| 215 | } |
| 216 | case e_while: { |
| 217 | double d = NAN; |
| 218 | while (eval_expr(p, e->param[0])) |
| 219 | d=eval_expr(p, e->param[1]); |
| 220 | return d; |
| 221 | } |
| 222 | case e_taylor: { |
| 223 | double t = 1, d = 0, v; |
| 224 | double x = eval_expr(p, e->param[1]); |
| 225 | int id = e->param[2] ? av_clip(eval_expr(p, e->param[2]), 0, VARS-1) : 0; |
| 226 | int i; |
| 227 | double var0 = p->var[id]; |
| 228 | for(i=0; i<1000; i++) { |
| 229 | double ld = d; |
| 230 | p->var[id] = i; |
| 231 | v = eval_expr(p, e->param[0]); |
| 232 | d += t*v; |
| 233 | if(ld==d && v) |
| 234 | break; |
| 235 | t *= x / (i+1); |
| 236 | } |
| 237 | p->var[id] = var0; |
| 238 | return d; |
| 239 | } |
| 240 | case e_root: { |
| 241 | int i, j; |
| 242 | double low = -1, high = -1, v, low_v = -DBL_MAX, high_v = DBL_MAX; |
| 243 | double var0 = p->var[0]; |
| 244 | double x_max = eval_expr(p, e->param[1]); |
| 245 | for(i=-1; i<1024; i++) { |
| 246 | if(i<255) { |
| 247 | p->var[0] = av_reverse[i&255]*x_max/255; |
| 248 | } else { |
| 249 | p->var[0] = x_max*pow(0.9, i-255); |
| 250 | if (i&1) p->var[0] *= -1; |
| 251 | if (i&2) p->var[0] += low; |
| 252 | else p->var[0] += high; |
| 253 | } |
| 254 | v = eval_expr(p, e->param[0]); |
| 255 | if (v<=0 && v>low_v) { |
| 256 | low = p->var[0]; |
| 257 | low_v = v; |
| 258 | } |
| 259 | if (v>=0 && v<high_v) { |
| 260 | high = p->var[0]; |
| 261 | high_v = v; |
| 262 | } |
| 263 | if (low>=0 && high>=0){ |
| 264 | for (j=0; j<1000; j++) { |
| 265 | p->var[0] = (low+high)*0.5; |
| 266 | if (low == p->var[0] || high == p->var[0]) |
| 267 | break; |
| 268 | v = eval_expr(p, e->param[0]); |
| 269 | if (v<=0) low = p->var[0]; |
| 270 | if (v>=0) high= p->var[0]; |
| 271 | if (isnan(v)) { |
| 272 | low = high = v; |
| 273 | break; |
| 274 | } |
| 275 | } |
| 276 | break; |
| 277 | } |
| 278 | } |
| 279 | p->var[0] = var0; |
| 280 | return -low_v<high_v ? low : high; |
| 281 | } |
| 282 | default: { |
| 283 | double d = eval_expr(p, e->param[0]); |
| 284 | double d2 = eval_expr(p, e->param[1]); |
| 285 | switch (e->type) { |
| 286 | case e_mod: return e->value * (d - floor((!CONFIG_FTRAPV || d2) ? d / d2 : d * INFINITY) * d2); |
| 287 | case e_gcd: return e->value * av_gcd(d,d2); |
| 288 | case e_max: return e->value * (d > d2 ? d : d2); |
| 289 | case e_min: return e->value * (d < d2 ? d : d2); |
| 290 | case e_eq: return e->value * (d == d2 ? 1.0 : 0.0); |
| 291 | case e_gt: return e->value * (d > d2 ? 1.0 : 0.0); |
| 292 | case e_gte: return e->value * (d >= d2 ? 1.0 : 0.0); |
| 293 | case e_lt: return e->value * (d < d2 ? 1.0 : 0.0); |
| 294 | case e_lte: return e->value * (d <= d2 ? 1.0 : 0.0); |
| 295 | case e_pow: return e->value * pow(d, d2); |
| 296 | case e_mul: return e->value * (d * d2); |
| 297 | case e_div: return e->value * ((!CONFIG_FTRAPV || d2 ) ? (d / d2) : d * INFINITY); |
| 298 | case e_add: return e->value * (d + d2); |
| 299 | case e_last:return e->value * d2; |
| 300 | case e_st : return e->value * (p->var[av_clip(d, 0, VARS-1)]= d2); |
| 301 | case e_hypot:return e->value * (sqrt(d*d + d2*d2)); |
| 302 | case e_bitand: return isnan(d) || isnan(d2) ? NAN : e->value * ((long int)d & (long int)d2); |
| 303 | case e_bitor: return isnan(d) || isnan(d2) ? NAN : e->value * ((long int)d | (long int)d2); |
| 304 | } |
| 305 | } |
| 306 | } |
| 307 | return NAN; |
| 308 | } |
| 309 | |
| 310 | static int parse_expr(AVExpr **e, Parser *p); |
| 311 | |
| 312 | void av_expr_free(AVExpr *e) |
| 313 | { |
| 314 | if (!e) return; |
| 315 | av_expr_free(e->param[0]); |
| 316 | av_expr_free(e->param[1]); |
| 317 | av_expr_free(e->param[2]); |
| 318 | av_freep(&e->var); |
| 319 | av_freep(&e); |
| 320 | } |
| 321 | |
| 322 | static int parse_primary(AVExpr **e, Parser *p) |
| 323 | { |
| 324 | AVExpr *d = av_mallocz(sizeof(AVExpr)); |
| 325 | char *next = p->s, *s0 = p->s; |
| 326 | int ret, i; |
| 327 | |
| 328 | if (!d) |
| 329 | return AVERROR(ENOMEM); |
| 330 | |
| 331 | /* number */ |
| 332 | d->value = av_strtod(p->s, &next); |
| 333 | if (next != p->s) { |
| 334 | d->type = e_value; |
| 335 | p->s= next; |
| 336 | *e = d; |
| 337 | return 0; |
| 338 | } |
| 339 | d->value = 1; |
| 340 | |
| 341 | /* named constants */ |
| 342 | for (i=0; p->const_names && p->const_names[i]; i++) { |
| 343 | if (strmatch(p->s, p->const_names[i])) { |
| 344 | p->s+= strlen(p->const_names[i]); |
| 345 | d->type = e_const; |
| 346 | d->a.const_index = i; |
| 347 | *e = d; |
| 348 | return 0; |
| 349 | } |
| 350 | } |
| 351 | for (i = 0; i < FF_ARRAY_ELEMS(constants); i++) { |
| 352 | if (strmatch(p->s, constants[i].name)) { |
| 353 | p->s += strlen(constants[i].name); |
| 354 | d->type = e_value; |
| 355 | d->value = constants[i].value; |
| 356 | *e = d; |
| 357 | return 0; |
| 358 | } |
| 359 | } |
| 360 | |
| 361 | p->s= strchr(p->s, '('); |
| 362 | if (!p->s) { |
| 363 | av_log(p, AV_LOG_ERROR, "Undefined constant or missing '(' in '%s'\n", s0); |
| 364 | p->s= next; |
| 365 | av_expr_free(d); |
| 366 | return AVERROR(EINVAL); |
| 367 | } |
| 368 | p->s++; // "(" |
| 369 | if (*next == '(') { // special case do-nothing |
| 370 | av_freep(&d); |
| 371 | if ((ret = parse_expr(&d, p)) < 0) |
| 372 | return ret; |
| 373 | if (p->s[0] != ')') { |
| 374 | av_log(p, AV_LOG_ERROR, "Missing ')' in '%s'\n", s0); |
| 375 | av_expr_free(d); |
| 376 | return AVERROR(EINVAL); |
| 377 | } |
| 378 | p->s++; // ")" |
| 379 | *e = d; |
| 380 | return 0; |
| 381 | } |
| 382 | if ((ret = parse_expr(&(d->param[0]), p)) < 0) { |
| 383 | av_expr_free(d); |
| 384 | return ret; |
| 385 | } |
| 386 | if (p->s[0]== ',') { |
| 387 | p->s++; // "," |
| 388 | parse_expr(&d->param[1], p); |
| 389 | } |
| 390 | if (p->s[0]== ',') { |
| 391 | p->s++; // "," |
| 392 | parse_expr(&d->param[2], p); |
| 393 | } |
| 394 | if (p->s[0] != ')') { |
| 395 | av_log(p, AV_LOG_ERROR, "Missing ')' or too many args in '%s'\n", s0); |
| 396 | av_expr_free(d); |
| 397 | return AVERROR(EINVAL); |
| 398 | } |
| 399 | p->s++; // ")" |
| 400 | |
| 401 | d->type = e_func0; |
| 402 | if (strmatch(next, "sinh" )) d->a.func0 = sinh; |
| 403 | else if (strmatch(next, "cosh" )) d->a.func0 = cosh; |
| 404 | else if (strmatch(next, "tanh" )) d->a.func0 = tanh; |
| 405 | else if (strmatch(next, "sin" )) d->a.func0 = sin; |
| 406 | else if (strmatch(next, "cos" )) d->a.func0 = cos; |
| 407 | else if (strmatch(next, "tan" )) d->a.func0 = tan; |
| 408 | else if (strmatch(next, "atan" )) d->a.func0 = atan; |
| 409 | else if (strmatch(next, "asin" )) d->a.func0 = asin; |
| 410 | else if (strmatch(next, "acos" )) d->a.func0 = acos; |
| 411 | else if (strmatch(next, "exp" )) d->a.func0 = exp; |
| 412 | else if (strmatch(next, "log" )) d->a.func0 = log; |
| 413 | else if (strmatch(next, "abs" )) d->a.func0 = fabs; |
| 414 | else if (strmatch(next, "time" )) d->a.func0 = etime; |
| 415 | else if (strmatch(next, "squish")) d->type = e_squish; |
| 416 | else if (strmatch(next, "gauss" )) d->type = e_gauss; |
| 417 | else if (strmatch(next, "mod" )) d->type = e_mod; |
| 418 | else if (strmatch(next, "max" )) d->type = e_max; |
| 419 | else if (strmatch(next, "min" )) d->type = e_min; |
| 420 | else if (strmatch(next, "eq" )) d->type = e_eq; |
| 421 | else if (strmatch(next, "gte" )) d->type = e_gte; |
| 422 | else if (strmatch(next, "gt" )) d->type = e_gt; |
| 423 | else if (strmatch(next, "lte" )) d->type = e_lte; |
| 424 | else if (strmatch(next, "lt" )) d->type = e_lt; |
| 425 | else if (strmatch(next, "ld" )) d->type = e_ld; |
| 426 | else if (strmatch(next, "isnan" )) d->type = e_isnan; |
| 427 | else if (strmatch(next, "isinf" )) d->type = e_isinf; |
| 428 | else if (strmatch(next, "st" )) d->type = e_st; |
| 429 | else if (strmatch(next, "while" )) d->type = e_while; |
| 430 | else if (strmatch(next, "taylor")) d->type = e_taylor; |
| 431 | else if (strmatch(next, "root" )) d->type = e_root; |
| 432 | else if (strmatch(next, "floor" )) d->type = e_floor; |
| 433 | else if (strmatch(next, "ceil" )) d->type = e_ceil; |
| 434 | else if (strmatch(next, "trunc" )) d->type = e_trunc; |
| 435 | else if (strmatch(next, "sqrt" )) d->type = e_sqrt; |
| 436 | else if (strmatch(next, "not" )) d->type = e_not; |
| 437 | else if (strmatch(next, "pow" )) d->type = e_pow; |
| 438 | else if (strmatch(next, "print" )) d->type = e_print; |
| 439 | else if (strmatch(next, "random")) d->type = e_random; |
| 440 | else if (strmatch(next, "hypot" )) d->type = e_hypot; |
| 441 | else if (strmatch(next, "gcd" )) d->type = e_gcd; |
| 442 | else if (strmatch(next, "if" )) d->type = e_if; |
| 443 | else if (strmatch(next, "ifnot" )) d->type = e_ifnot; |
| 444 | else if (strmatch(next, "bitand")) d->type = e_bitand; |
| 445 | else if (strmatch(next, "bitor" )) d->type = e_bitor; |
| 446 | else if (strmatch(next, "between"))d->type = e_between; |
| 447 | else if (strmatch(next, "clip" )) d->type = e_clip; |
| 448 | else { |
| 449 | for (i=0; p->func1_names && p->func1_names[i]; i++) { |
| 450 | if (strmatch(next, p->func1_names[i])) { |
| 451 | d->a.func1 = p->funcs1[i]; |
| 452 | d->type = e_func1; |
| 453 | *e = d; |
| 454 | return 0; |
| 455 | } |
| 456 | } |
| 457 | |
| 458 | for (i=0; p->func2_names && p->func2_names[i]; i++) { |
| 459 | if (strmatch(next, p->func2_names[i])) { |
| 460 | d->a.func2 = p->funcs2[i]; |
| 461 | d->type = e_func2; |
| 462 | *e = d; |
| 463 | return 0; |
| 464 | } |
| 465 | } |
| 466 | |
| 467 | av_log(p, AV_LOG_ERROR, "Unknown function in '%s'\n", s0); |
| 468 | av_expr_free(d); |
| 469 | return AVERROR(EINVAL); |
| 470 | } |
| 471 | |
| 472 | *e = d; |
| 473 | return 0; |
| 474 | } |
| 475 | |
| 476 | static AVExpr *make_eval_expr(int type, int value, AVExpr *p0, AVExpr *p1) |
| 477 | { |
| 478 | AVExpr *e = av_mallocz(sizeof(AVExpr)); |
| 479 | if (!e) |
| 480 | return NULL; |
| 481 | e->type =type ; |
| 482 | e->value =value ; |
| 483 | e->param[0] =p0 ; |
| 484 | e->param[1] =p1 ; |
| 485 | return e; |
| 486 | } |
| 487 | |
| 488 | static int parse_pow(AVExpr **e, Parser *p, int *sign) |
| 489 | { |
| 490 | *sign= (*p->s == '+') - (*p->s == '-'); |
| 491 | p->s += *sign&1; |
| 492 | return parse_primary(e, p); |
| 493 | } |
| 494 | |
| 495 | static int parse_dB(AVExpr **e, Parser *p, int *sign) |
| 496 | { |
| 497 | /* do not filter out the negative sign when parsing a dB value. |
| 498 | for example, -3dB is not the same as -(3dB) */ |
| 499 | if (*p->s == '-') { |
| 500 | char *next; |
| 501 | double av_unused ignored = strtod(p->s, &next); |
| 502 | if (next != p->s && next[0] == 'd' && next[1] == 'B') { |
| 503 | *sign = 0; |
| 504 | return parse_primary(e, p); |
| 505 | } |
| 506 | } |
| 507 | return parse_pow(e, p, sign); |
| 508 | } |
| 509 | |
| 510 | static int parse_factor(AVExpr **e, Parser *p) |
| 511 | { |
| 512 | int sign, sign2, ret; |
| 513 | AVExpr *e0, *e1, *e2; |
| 514 | if ((ret = parse_dB(&e0, p, &sign)) < 0) |
| 515 | return ret; |
| 516 | while(p->s[0]=='^'){ |
| 517 | e1 = e0; |
| 518 | p->s++; |
| 519 | if ((ret = parse_dB(&e2, p, &sign2)) < 0) { |
| 520 | av_expr_free(e1); |
| 521 | return ret; |
| 522 | } |
| 523 | e0 = make_eval_expr(e_pow, 1, e1, e2); |
| 524 | if (!e0) { |
| 525 | av_expr_free(e1); |
| 526 | av_expr_free(e2); |
| 527 | return AVERROR(ENOMEM); |
| 528 | } |
| 529 | if (e0->param[1]) e0->param[1]->value *= (sign2|1); |
| 530 | } |
| 531 | if (e0) e0->value *= (sign|1); |
| 532 | |
| 533 | *e = e0; |
| 534 | return 0; |
| 535 | } |
| 536 | |
| 537 | static int parse_term(AVExpr **e, Parser *p) |
| 538 | { |
| 539 | int ret; |
| 540 | AVExpr *e0, *e1, *e2; |
| 541 | if ((ret = parse_factor(&e0, p)) < 0) |
| 542 | return ret; |
| 543 | while (p->s[0]=='*' || p->s[0]=='/') { |
| 544 | int c= *p->s++; |
| 545 | e1 = e0; |
| 546 | if ((ret = parse_factor(&e2, p)) < 0) { |
| 547 | av_expr_free(e1); |
| 548 | return ret; |
| 549 | } |
| 550 | e0 = make_eval_expr(c == '*' ? e_mul : e_div, 1, e1, e2); |
| 551 | if (!e0) { |
| 552 | av_expr_free(e1); |
| 553 | av_expr_free(e2); |
| 554 | return AVERROR(ENOMEM); |
| 555 | } |
| 556 | } |
| 557 | *e = e0; |
| 558 | return 0; |
| 559 | } |
| 560 | |
| 561 | static int parse_subexpr(AVExpr **e, Parser *p) |
| 562 | { |
| 563 | int ret; |
| 564 | AVExpr *e0, *e1, *e2; |
| 565 | if ((ret = parse_term(&e0, p)) < 0) |
| 566 | return ret; |
| 567 | while (*p->s == '+' || *p->s == '-') { |
| 568 | e1 = e0; |
| 569 | if ((ret = parse_term(&e2, p)) < 0) { |
| 570 | av_expr_free(e1); |
| 571 | return ret; |
| 572 | } |
| 573 | e0 = make_eval_expr(e_add, 1, e1, e2); |
| 574 | if (!e0) { |
| 575 | av_expr_free(e1); |
| 576 | av_expr_free(e2); |
| 577 | return AVERROR(ENOMEM); |
| 578 | } |
| 579 | }; |
| 580 | |
| 581 | *e = e0; |
| 582 | return 0; |
| 583 | } |
| 584 | |
| 585 | static int parse_expr(AVExpr **e, Parser *p) |
| 586 | { |
| 587 | int ret; |
| 588 | AVExpr *e0, *e1, *e2; |
| 589 | if (p->stack_index <= 0) //protect against stack overflows |
| 590 | return AVERROR(EINVAL); |
| 591 | p->stack_index--; |
| 592 | |
| 593 | if ((ret = parse_subexpr(&e0, p)) < 0) |
| 594 | return ret; |
| 595 | while (*p->s == ';') { |
| 596 | p->s++; |
| 597 | e1 = e0; |
| 598 | if ((ret = parse_subexpr(&e2, p)) < 0) { |
| 599 | av_expr_free(e1); |
| 600 | return ret; |
| 601 | } |
| 602 | e0 = make_eval_expr(e_last, 1, e1, e2); |
| 603 | if (!e0) { |
| 604 | av_expr_free(e1); |
| 605 | av_expr_free(e2); |
| 606 | return AVERROR(ENOMEM); |
| 607 | } |
| 608 | }; |
| 609 | |
| 610 | p->stack_index++; |
| 611 | *e = e0; |
| 612 | return 0; |
| 613 | } |
| 614 | |
| 615 | static int verify_expr(AVExpr *e) |
| 616 | { |
| 617 | if (!e) return 0; |
| 618 | switch (e->type) { |
| 619 | case e_value: |
| 620 | case e_const: return 1; |
| 621 | case e_func0: |
| 622 | case e_func1: |
| 623 | case e_squish: |
| 624 | case e_ld: |
| 625 | case e_gauss: |
| 626 | case e_isnan: |
| 627 | case e_isinf: |
| 628 | case e_floor: |
| 629 | case e_ceil: |
| 630 | case e_trunc: |
| 631 | case e_sqrt: |
| 632 | case e_not: |
| 633 | case e_random: |
| 634 | return verify_expr(e->param[0]) && !e->param[1]; |
| 635 | case e_print: |
| 636 | return verify_expr(e->param[0]) |
| 637 | && (!e->param[1] || verify_expr(e->param[1])); |
| 638 | case e_if: |
| 639 | case e_ifnot: |
| 640 | case e_taylor: |
| 641 | return verify_expr(e->param[0]) && verify_expr(e->param[1]) |
| 642 | && (!e->param[2] || verify_expr(e->param[2])); |
| 643 | case e_between: |
| 644 | case e_clip: |
| 645 | return verify_expr(e->param[0]) && |
| 646 | verify_expr(e->param[1]) && |
| 647 | verify_expr(e->param[2]); |
| 648 | default: return verify_expr(e->param[0]) && verify_expr(e->param[1]) && !e->param[2]; |
| 649 | } |
| 650 | } |
| 651 | |
| 652 | int av_expr_parse(AVExpr **expr, const char *s, |
| 653 | const char * const *const_names, |
| 654 | const char * const *func1_names, double (* const *funcs1)(void *, double), |
| 655 | const char * const *func2_names, double (* const *funcs2)(void *, double, double), |
| 656 | int log_offset, void *log_ctx) |
| 657 | { |
| 658 | Parser p = { 0 }; |
| 659 | AVExpr *e = NULL; |
| 660 | char *w = av_malloc(strlen(s) + 1); |
| 661 | char *wp = w; |
| 662 | const char *s0 = s; |
| 663 | int ret = 0; |
| 664 | |
| 665 | if (!w) |
| 666 | return AVERROR(ENOMEM); |
| 667 | |
| 668 | while (*s) |
| 669 | if (!av_isspace(*s++)) *wp++ = s[-1]; |
| 670 | *wp++ = 0; |
| 671 | |
| 672 | p.class = &eval_class; |
| 673 | p.stack_index=100; |
| 674 | p.s= w; |
| 675 | p.const_names = const_names; |
| 676 | p.funcs1 = funcs1; |
| 677 | p.func1_names = func1_names; |
| 678 | p.funcs2 = funcs2; |
| 679 | p.func2_names = func2_names; |
| 680 | p.log_offset = log_offset; |
| 681 | p.log_ctx = log_ctx; |
| 682 | |
| 683 | if ((ret = parse_expr(&e, &p)) < 0) |
| 684 | goto end; |
| 685 | if (*p.s) { |
| 686 | av_expr_free(e); |
| 687 | av_log(&p, AV_LOG_ERROR, "Invalid chars '%s' at the end of expression '%s'\n", p.s, s0); |
| 688 | ret = AVERROR(EINVAL); |
| 689 | goto end; |
| 690 | } |
| 691 | if (!verify_expr(e)) { |
| 692 | av_expr_free(e); |
| 693 | ret = AVERROR(EINVAL); |
| 694 | goto end; |
| 695 | } |
| 696 | e->var= av_mallocz(sizeof(double) *VARS); |
| 697 | *expr = e; |
| 698 | end: |
| 699 | av_free(w); |
| 700 | return ret; |
| 701 | } |
| 702 | |
| 703 | double av_expr_eval(AVExpr *e, const double *const_values, void *opaque) |
| 704 | { |
| 705 | Parser p = { 0 }; |
| 706 | p.var= e->var; |
| 707 | |
| 708 | p.const_values = const_values; |
| 709 | p.opaque = opaque; |
| 710 | return eval_expr(&p, e); |
| 711 | } |
| 712 | |
| 713 | int av_expr_parse_and_eval(double *d, const char *s, |
| 714 | const char * const *const_names, const double *const_values, |
| 715 | const char * const *func1_names, double (* const *funcs1)(void *, double), |
| 716 | const char * const *func2_names, double (* const *funcs2)(void *, double, double), |
| 717 | void *opaque, int log_offset, void *log_ctx) |
| 718 | { |
| 719 | AVExpr *e = NULL; |
| 720 | int ret = av_expr_parse(&e, s, const_names, func1_names, funcs1, func2_names, funcs2, log_offset, log_ctx); |
| 721 | |
| 722 | if (ret < 0) { |
| 723 | *d = NAN; |
| 724 | return ret; |
| 725 | } |
| 726 | *d = av_expr_eval(e, const_values, opaque); |
| 727 | av_expr_free(e); |
| 728 | return isnan(*d) ? AVERROR(EINVAL) : 0; |
| 729 | } |
| 730 | |
| 731 | #ifdef TEST |
| 732 | #include <string.h> |
| 733 | |
| 734 | static const double const_values[] = { |
| 735 | M_PI, |
| 736 | M_E, |
| 737 | 0 |
| 738 | }; |
| 739 | |
| 740 | static const char *const const_names[] = { |
| 741 | "PI", |
| 742 | "E", |
| 743 | 0 |
| 744 | }; |
| 745 | |
| 746 | int main(int argc, char **argv) |
| 747 | { |
| 748 | int i; |
| 749 | double d; |
| 750 | const char *const *expr; |
| 751 | static const char *const exprs[] = { |
| 752 | "", |
| 753 | "1;2", |
| 754 | "-20", |
| 755 | "-PI", |
| 756 | "+PI", |
| 757 | "1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)", |
| 758 | "80G/80Gi", |
| 759 | "1k", |
| 760 | "1Gi", |
| 761 | "1gi", |
| 762 | "1GiFoo", |
| 763 | "1k+1k", |
| 764 | "1Gi*3foo", |
| 765 | "foo", |
| 766 | "foo(", |
| 767 | "foo()", |
| 768 | "foo)", |
| 769 | "sin", |
| 770 | "sin(", |
| 771 | "sin()", |
| 772 | "sin)", |
| 773 | "sin 10", |
| 774 | "sin(1,2,3)", |
| 775 | "sin(1 )", |
| 776 | "1", |
| 777 | "1foo", |
| 778 | "bar + PI + E + 100f*2 + foo", |
| 779 | "13k + 12f - foo(1, 2)", |
| 780 | "1gi", |
| 781 | "1Gi", |
| 782 | "st(0, 123)", |
| 783 | "st(1, 123); ld(1)", |
| 784 | "lte(0, 1)", |
| 785 | "lte(1, 1)", |
| 786 | "lte(1, 0)", |
| 787 | "lt(0, 1)", |
| 788 | "lt(1, 1)", |
| 789 | "gt(1, 0)", |
| 790 | "gt(2, 7)", |
| 791 | "gte(122, 122)", |
| 792 | /* compute 1+2+...+N */ |
| 793 | "st(0, 1); while(lte(ld(0), 100), st(1, ld(1)+ld(0));st(0, ld(0)+1)); ld(1)", |
| 794 | /* compute Fib(N) */ |
| 795 | "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)", |
| 796 | "while(0, 10)", |
| 797 | "st(0, 1); while(lte(ld(0),100), st(1, ld(1)+ld(0)); st(0, ld(0)+1))", |
| 798 | "isnan(1)", |
| 799 | "isnan(NAN)", |
| 800 | "isnan(INF)", |
| 801 | "isinf(1)", |
| 802 | "isinf(NAN)", |
| 803 | "isinf(INF)", |
| 804 | "floor(NAN)", |
| 805 | "floor(123.123)", |
| 806 | "floor(-123.123)", |
| 807 | "trunc(123.123)", |
| 808 | "trunc(-123.123)", |
| 809 | "ceil(123.123)", |
| 810 | "ceil(-123.123)", |
| 811 | "sqrt(1764)", |
| 812 | "isnan(sqrt(-1))", |
| 813 | "not(1)", |
| 814 | "not(NAN)", |
| 815 | "not(0)", |
| 816 | "6.0206dB", |
| 817 | "-3.0103dB", |
| 818 | "pow(0,1.23)", |
| 819 | "pow(PI,1.23)", |
| 820 | "PI^1.23", |
| 821 | "pow(-1,1.23)", |
| 822 | "if(1, 2)", |
| 823 | "if(1, 1, 2)", |
| 824 | "if(0, 1, 2)", |
| 825 | "ifnot(0, 23)", |
| 826 | "ifnot(1, NaN) + if(0, 1)", |
| 827 | "ifnot(1, 1, 2)", |
| 828 | "ifnot(0, 1, 2)", |
| 829 | "taylor(1, 1)", |
| 830 | "taylor(eq(mod(ld(1),4),1)-eq(mod(ld(1),4),3), PI/2, 1)", |
| 831 | "root(sin(ld(0))-1, 2)", |
| 832 | "root(sin(ld(0))+6+sin(ld(0)/12)-log(ld(0)), 100)", |
| 833 | "7000000B*random(0)", |
| 834 | "squish(2)", |
| 835 | "gauss(0.1)", |
| 836 | "hypot(4,3)", |
| 837 | "gcd(30,55)*print(min(9,1))", |
| 838 | "bitor(42, 12)", |
| 839 | "bitand(42, 12)", |
| 840 | "bitand(NAN, 1)", |
| 841 | "between(10, -3, 10)", |
| 842 | "between(-4, -2, -1)", |
| 843 | "between(1,2)", |
| 844 | "clip(0, 2, 1)", |
| 845 | "clip(0/0, 1, 2)", |
| 846 | "clip(0, 0/0, 1)", |
| 847 | NULL |
| 848 | }; |
| 849 | |
| 850 | for (expr = exprs; *expr; expr++) { |
| 851 | printf("Evaluating '%s'\n", *expr); |
| 852 | av_expr_parse_and_eval(&d, *expr, |
| 853 | const_names, const_values, |
| 854 | NULL, NULL, NULL, NULL, NULL, 0, NULL); |
| 855 | if (isnan(d)) |
| 856 | printf("'%s' -> nan\n\n", *expr); |
| 857 | else |
| 858 | printf("'%s' -> %f\n\n", *expr, d); |
| 859 | } |
| 860 | |
| 861 | av_expr_parse_and_eval(&d, "1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)", |
| 862 | const_names, const_values, |
| 863 | NULL, NULL, NULL, NULL, NULL, 0, NULL); |
| 864 | printf("%f == 12.7\n", d); |
| 865 | av_expr_parse_and_eval(&d, "80G/80Gi", |
| 866 | const_names, const_values, |
| 867 | NULL, NULL, NULL, NULL, NULL, 0, NULL); |
| 868 | printf("%f == 0.931322575\n", d); |
| 869 | |
| 870 | if (argc > 1 && !strcmp(argv[1], "-t")) { |
| 871 | for (i = 0; i < 1050; i++) { |
| 872 | START_TIMER; |
| 873 | av_expr_parse_and_eval(&d, "1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)", |
| 874 | const_names, const_values, |
| 875 | NULL, NULL, NULL, NULL, NULL, 0, NULL); |
| 876 | STOP_TIMER("av_expr_parse_and_eval"); |
| 877 | } |
| 878 | } |
| 879 | |
| 880 | return 0; |
| 881 | } |
| 882 | #endif |