FFmpeg: libavutil/eval.c Source File

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libavutil

eval.c

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1 /*

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 */

22 /**

23 * @file

24 * simple arithmetic expression evaluator.

25 *

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

27 */

29 #include <float.h>

30 #include "avutil.h"

31 #include "common.h"

32 #include "eval.h"

33 #include "log.h"

34 #include "mathematics.h"

35 #include "time.h"

36 #include "avstring.h"

38 typedef struct Parser {

39 const AVClass *class;

40 int stack_index;

41 char *s;

42 const double *const_values;

43 const char * const *const_names; // NULL terminated

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

45 const char * const *func1_names; // NULL terminated

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

47 const char * const *func2_names; // NULL terminated

48 void *opaque;

49 int log_offset;

50 void *log_ctx;

51 #define VARS 10

52 double *var;

53 } Parser;

55 static const AVClass eval_class = { "Eval", av_default_item_name, NULL, LIBAVUTIL_VERSION_INT, offsetof(Parser,log_offset), offsetof(Parser,log_ctx) };

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

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

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

60 ['a'-'E']= -18,

61 ['f'-'E']= -15,

62 ['p'-'E']= -12,

63 ['n'-'E']= - 9,

64 ['u'-'E']= - 6,

65 ['m'-'E']= - 3,

66 ['c'-'E']= - 2,

67 ['d'-'E']= - 1,

68 ['h'-'E']= 2,

69 ['k'-'E']= 3,

70 ['K'-'E']= 3,

71 ['M'-'E']= 6,

72 ['G'-'E']= 9,

73 ['T'-'E']= 12,

74 ['P'-'E']= 15,

75 ['E'-'E']= 18,

76 ['Z'-'E']= 21,

77 ['Y'-'E']= 24,

78 };

80 static const struct {

81 const char *name;

82 double value;

83 } constants[] = {

84 { "E", M_E },

85 { "PI", M_PI },

86 { "PHI", M_PHI },

87 };

89 double av_strtod(const char *numstr, char **tail)

90 {

91 double d;

92 char *next;

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

94 d = strtoul(numstr, &next, 16);

95 } else

96 d = strtod(numstr, &next);

97 /* if parsing succeeded, check for and interpret postfixes */

98 if (next!=numstr) {

99 if (next[0] == 'd' && next[1] == 'B') {

100 /* treat dB as decibels instead of decibytes */

101 d = pow(10, d / 20);

102 next += 2;

103 } else if (*next >= 'E' && *next <= 'z') {

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

105 if (e) {

106 if (next[1] == 'i') {

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

108 next+=2;

109 } else {

110 d*= pow(10, e);

111 next++;

112 }

113 }

114 }

115

116 if (*next=='B') {

117 d*=8;

118 next++;

119 }

120 }

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

122 character */

123 if (tail)

124 *tail = next;

125 return d;

126 }

127

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

129

130 static int strmatch(const char *s, const char *prefix)

131 {

132 int i;

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

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

135 }

136 /* return 1 only if the s identifier is terminated */

137 return !IS_IDENTIFIER_CHAR(s[i]);

138 }

139

140 struct AVExpr {

141 enum {

142 e_value, e_const, e_func0, e_func1, e_func2,

143 e_squish, e_gauss, e_ld, e_isnan, e_isinf,

144 e_mod, e_max, e_min, e_eq, e_gt, e_gte, e_lte, e_lt,

145 e_pow, e_mul, e_div, e_add,

146 e_last, e_st, e_while, e_taylor, e_root, e_floor, e_ceil, e_trunc,

147 e_sqrt, e_not, e_random, e_hypot, e_gcd,

148 e_if, e_ifnot, e_print, e_bitand, e_bitor, e_between,

149 } type;

150 double value; // is sign in other types

151 union {

152 int const_index;

153 double (*func0)(double);

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

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

156 } a;

157 struct AVExpr *param[3];

158 double *var;

159 };

160

161 static double etime(double v)

162 {

163 return av_gettime() * 0.000001;

164 }

165

166 static double eval_expr(Parser *p, AVExpr *e)

167 {

168 switch (e->type) {

169 case e_value: return e->value;

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

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

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

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

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

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

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

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

178 case e_isinf: return e->value * !!isinf(eval_expr(p, e->param[0]));

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

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

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

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

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

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

185 e->param[2] ? eval_expr(p, e->param[2]) : 0);

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

187 e->param[2] ? eval_expr(p, e->param[2]) : 0);

188 case e_between: {

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

190 return e->value * (d >= eval_expr(p, e->param[1]) &&

191 d <= eval_expr(p, e->param[2]));

192 }

193 case e_print: {

194 double x = eval_expr(p, e->param[0]);

195 int level = e->param[1] ? av_clip(eval_expr(p, e->param[1]), INT_MIN, INT_MAX) : AV_LOG_INFO;

196 av_log(p, level, "%f\n", x);

197 return x;

198 }

199 case e_random:{

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

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

202 r= r*1664525+1013904223;

203 p->var[idx]= r;

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

205 }

206 case e_while: {

207 double d = NAN;

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

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

210 return d;

211 }

212 case e_taylor: {

213 double t = 1, d = 0, v;

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

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

216 int i;

217 double var0 = p->var[id];

218 for(i=0; i<1000; i++) {

219 double ld = d;

220 p->var[id] = i;

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

222 d += t*v;

223 if(ld==d && v)

224 break;

225 t *= x / (i+1);

226 }

227 p->var[id] = var0;

228 return d;

229 }

230 case e_root: {

231 int i, j;

232 double low = -1, high = -1, v, low_v = -DBL_MAX, high_v = DBL_MAX;

233 double var0 = p->var[0];

234 double x_max = eval_expr(p, e->param[1]);

235 for(i=-1; i<1024; i++) {

236 if(i<255) {

237 p->var[0] = av_reverse[i&255]*x_max/255;

238 } else {

239 p->var[0] = x_max*pow(0.9, i-255);

240 if (i&1) p->var[0] *= -1;

241 if (i&2) p->var[0] += low;

242 else p->var[0] += high;

243 }

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

245 if (v<=0 && v>low_v) {

246 low = p->var[0];

247 low_v = v;

248 }

249 if (v>=0 && v<high_v) {

250 high = p->var[0];

251 high_v = v;

252 }

253 if (low>=0 && high>=0){

254 for (j=0; j<1000; j++) {

255 p->var[0] = (low+high)*0.5;

256 if (low == p->var[0] || high == p->var[0])

257 break;

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

259 if (v<=0) low = p->var[0];

260 if (v>=0) high= p->var[0];

261 if (isnan(v)) {

262 low = high = v;

263 break;

264 }

265 }

266 break;

267 }

268 }

269 p->var[0] = var0;

270 return -low_v<high_v ? low : high;

271 }

272 default: {

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

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

275 switch (e->type) {

276 case e_mod: return e->value * (d - floor((!CONFIG_FTRAPV || d2) ? d / d2 : d * INFINITY) * d2);

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

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

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

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

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

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

283 case e_lt: return e->value * (d < d2 ? 1.0 : 0.0);

284 case e_lte: return e->value * (d <= d2 ? 1.0 : 0.0);

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

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

287 case e_div: return e->value * ((!CONFIG_FTRAPV || d2 ) ? (d / d2) : d * INFINITY);

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

289 case e_last:return e->value * d2;

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

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

292 case e_bitand: return isnan(d) || isnan(d2) ? NAN : e->value * ((long int)d & (long int)d2);

293 case e_bitor: return isnan(d) || isnan(d2) ? NAN : e->value * ((long int)d | (long int)d2);

294 }

295 }

296 }

297 return NAN;

298 }

299

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

301

302 void av_expr_free(AVExpr *e)

303 {

304 if (!e) return;

305 av_expr_free(e->param[0]);

306 av_expr_free(e->param[1]);

307 av_expr_free(e->param[2]);

308 av_freep(&e->var);

309 av_freep(&e);

310 }

311

312 static int parse_primary(AVExpr **e, Parser *p)

313 {

314 AVExpr *d = av_mallocz(sizeof(AVExpr));

315 char *next = p->s, *s0 = p->s;

316 int ret, i;

317

318 if (!d)

319 return AVERROR(ENOMEM);

320

321 /* number */

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

323 if (next != p->s) {

324 d->type = e_value;

325 p->s= next;

326 *e = d;

327 return 0;

328 }

329 d->value = 1;

330

331 /* named constants */

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

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

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

335 d->type = e_const;

336 d->a.const_index = i;

337 *e = d;

338 return 0;

339 }

340 }

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

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

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

344 d->type = e_value;

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

346 *e = d;

347 return 0;

348 }

349 }

350

351 p->s= strchr(p->s, '(');

352 if (p->s==NULL) {

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

354 p->s= next;

355 av_expr_free(d);

356 return AVERROR(EINVAL);

357 }

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

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

360 av_freep(&d);

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

362 return ret;

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

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

365 av_expr_free(d);

366 return AVERROR(EINVAL);

367 }

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

369 *e = d;

370 return 0;

371 }

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

373 av_expr_free(d);

374 return ret;

375 }

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

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

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

379 }

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

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

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

383 }

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

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

386 av_expr_free(d);

387 return AVERROR(EINVAL);

388 }

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

390

391 d->type = e_func0;

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

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

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

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

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

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

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

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

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

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

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

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

404 else if (strmatch(next, "time" )) d->a.func0 = etime;

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

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

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

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

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

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

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

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

413 else if (strmatch(next, "lte" )) d->type = e_lte;

414 else if (strmatch(next, "lt" )) d->type = e_lt;

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

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

417 else if (strmatch(next, "isinf" )) d->type = e_isinf;

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

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

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

421 else if (strmatch(next, "root" )) d->type = e_root;

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

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

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

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

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

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

428 else if (strmatch(next, "print" )) d->type = e_print;

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

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

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

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

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

434 else if (strmatch(next, "bitand")) d->type = e_bitand;

435 else if (strmatch(next, "bitor" )) d->type = e_bitor;

436 else if (strmatch(next, "between"))d->type = e_between;

437 else {

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

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

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

441 d->type = e_func1;

442 *e = d;

443 return 0;

444 }

445 }

446

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

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

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

450 d->type = e_func2;

451 *e = d;

452 return 0;

453 }

454 }

455

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

457 av_expr_free(d);

458 return AVERROR(EINVAL);

459 }

460

461 *e = d;

462 return 0;

463 }

464

465 static AVExpr *make_eval_expr(int type, int value, AVExpr *p0, AVExpr *p1)

466 {

467 AVExpr *e = av_mallocz(sizeof(AVExpr));

468 if (!e)

469 return NULL;

470 e->type =type ;

471 e->value =value ;

472 e->param[0] =p0 ;

473 e->param[1] =p1 ;

474 return e;

475 }

476

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

478 {

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

480 p->s += *sign&1;

481 return parse_primary(e, p);

482 }

483

484 static int parse_dB(AVExpr **e, Parser *p, int *sign)

485 {

486 /* do not filter out the negative sign when parsing a dB value.

487 for example, -3dB is not the same as -(3dB) */

488 if (*p->s == '-') {

489 char *next;

490 double av_unused v = strtod(p->s, &next);

491 if (next != p->s && next[0] == 'd' && next[1] == 'B') {

492 *sign = 0;

493 return parse_primary(e, p);

494 }

495 }

496 return parse_pow(e, p, sign);

497 }

498

499 static int parse_factor(AVExpr **e, Parser *p)

500 {

501 int sign, sign2, ret;

502 AVExpr *e0, *e1, *e2;

503 if ((ret = parse_dB(&e0, p, &sign)) < 0)

504 return ret;

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

506 e1 = e0;

507 p->s++;

508 if ((ret = parse_dB(&e2, p, &sign2)) < 0) {

509 av_expr_free(e1);

510 return ret;

511 }

512 e0 = make_eval_expr(e_pow, 1, e1, e2);

513 if (!e0) {

514 av_expr_free(e1);

515 av_expr_free(e2);

516 return AVERROR(ENOMEM);

517 }

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

519 }

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

521

522 *e = e0;

523 return 0;

524 }

525

526 static int parse_term(AVExpr **e, Parser *p)

527 {

528 int ret;

529 AVExpr *e0, *e1, *e2;

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

531 return ret;

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

533 int c= *p->s++;

534 e1 = e0;

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

536 av_expr_free(e1);

537 return ret;

538 }

539 e0 = make_eval_expr(c == '*' ? e_mul : e_div, 1, e1, e2);

540 if (!e0) {

541 av_expr_free(e1);

542 av_expr_free(e2);

543 return AVERROR(ENOMEM);

544 }

545 }

546 *e = e0;

547 return 0;

548 }

549

550 static int parse_subexpr(AVExpr **e, Parser *p)

551 {

552 int ret;

553 AVExpr *e0, *e1, *e2;

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

555 return ret;

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

557 e1 = e0;

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

559 av_expr_free(e1);

560 return ret;

561 }

562 e0 = make_eval_expr(e_add, 1, e1, e2);

563 if (!e0) {

564 av_expr_free(e1);

565 av_expr_free(e2);

566 return AVERROR(ENOMEM);

567 }

568 };

569

570 *e = e0;

571 return 0;

572 }

573

574 static int parse_expr(AVExpr **e, Parser *p)

575 {

576 int ret;

577 AVExpr *e0, *e1, *e2;

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

579 return AVERROR(EINVAL);

580 p->stack_index--;

581

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

583 return ret;

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

585 p->s++;

586 e1 = e0;

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

588 av_expr_free(e1);

589 return ret;

590 }

591 e0 = make_eval_expr(e_last, 1, e1, e2);

592 if (!e0) {

593 av_expr_free(e1);

594 av_expr_free(e2);

595 return AVERROR(ENOMEM);

596 }

597 };

598

599 p->stack_index++;

600 *e = e0;

601 return 0;

602 }

603

604 static int verify_expr(AVExpr *e)

605 {

606 if (!e) return 0;

607 switch (e->type) {

608 case e_value:

609 case e_const: return 1;

610 case e_func0:

611 case e_func1:

612 case e_squish:

613 case e_ld:

614 case e_gauss:

615 case e_isnan:

616 case e_isinf:

617 case e_floor:

618 case e_ceil:

619 case e_trunc:

620 case e_sqrt:

621 case e_not:

622 case e_random:

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

624 case e_print:

625 return verify_expr(e->param[0])

626 && (!e->param[1] || verify_expr(e->param[1]));

627 case e_if:

628 case e_ifnot:

629 case e_taylor:

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

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

632 case e_between:

633 return verify_expr(e->param[0]) &&

634 verify_expr(e->param[1]) &&

635 verify_expr(e->param[2]);

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

637 }

638 }

639

640 int av_expr_parse(AVExpr **expr, const char *s,

641 const char * const *const_names,

642 const char * const *func1_names, double (* const *funcs1)(void *, double),

643 const char * const *func2_names, double (* const *funcs2)(void *, double, double),

644 int log_offset, void *log_ctx)

645 {

646 Parser p = { 0 };

647 AVExpr *e = NULL;

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

649 char *wp = w;

650 const char *s0 = s;

651 int ret = 0;

652

653 if (!w)

654 return AVERROR(ENOMEM);

655

656 while (*s)

657 if (!av_isspace(*s++)) *wp++ = s[-1];

658 *wp++ = 0;

659

660 p.class = &eval_class;

661 p.stack_index=100;

662 p.s= w;

663 p.const_names = const_names;

664 p.funcs1 = funcs1;

665 p.func1_names = func1_names;

666 p.funcs2 = funcs2;

667 p.func2_names = func2_names;

668 p.log_offset = log_offset;

669 p.log_ctx = log_ctx;

670

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

672 goto end;

673 if (*p.s) {

674 av_expr_free(e);

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

676 ret = AVERROR(EINVAL);

677 goto end;

678 }

679 if (!verify_expr(e)) {

680 av_expr_free(e);

681 ret = AVERROR(EINVAL);

682 goto end;

683 }

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

685 *expr = e;

686 end:

687 av_free(w);

688 return ret;

689 }

690

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

692 {

693 Parser p = { 0 };

694 p.var= e->var;

695

696 p.const_values = const_values;

697 p.opaque = opaque;

698 return eval_expr(&p, e);

699 }

700

701 int av_expr_parse_and_eval(double *d, const char *s,

702 const char * const *const_names, const double *const_values,

703 const char * const *func1_names, double (* const *funcs1)(void *, double),

704 const char * const *func2_names, double (* const *funcs2)(void *, double, double),

705 void *opaque, int log_offset, void *log_ctx)

706 {

707 AVExpr *e = NULL;

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

709

710 if (ret < 0) {

711 *d = NAN;

712 return ret;

713 }

714 *d = av_expr_eval(e, const_values, opaque);

715 av_expr_free(e);

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

717 }

718

719 #ifdef TEST

720 #include <string.h>

721

722 static const double const_values[] = {

723 M_PI,

724 M_E,

725 0

726 };

727

728 static const char *const const_names[] = {

729 "PI",

730 "E",

731 0

732 };

733

734 int main(int argc, char **argv)

735 {

736 int i;

737 double d;

738 const char *const *expr;

739 static const char *const exprs[] = {

740 "",

741 "1;2",

742 "-20",

743 "-PI",

744 "+PI",

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

746 "80G/80Gi",

747 "1k",

748 "1Gi",

749 "1gi",

750 "1GiFoo",

751 "1k+1k",

752 "1Gi*3foo",

753 "foo",

754 "foo(",

755 "foo()",

756 "foo)",

757 "sin",

758 "sin(",

759 "sin()",

760 "sin)",

761 "sin 10",

762 "sin(1,2,3)",

763 "sin(1 )",

764 "1",

765 "1foo",

766 "bar + PI + E + 100f*2 + foo",

767 "13k + 12f - foo(1, 2)",

768 "1gi",

769 "1Gi",

770 "st(0, 123)",

771 "st(1, 123); ld(1)",

772 "lte(0, 1)",

773 "lte(1, 1)",

774 "lte(1, 0)",

775 "lt(0, 1)",

776 "lt(1, 1)",

777 "gt(1, 0)",

778 "gt(2, 7)",

779 "gte(122, 122)",

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

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

782 /* compute Fib(N) */

783 "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)",

784 "while(0, 10)",

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

786 "isnan(1)",

787 "isnan(NAN)",

788 "isnan(INF)",

789 "isinf(1)",

790 "isinf(NAN)",

791 "isinf(INF)",

792 "floor(NAN)",

793 "floor(123.123)",

794 "floor(-123.123)",

795 "trunc(123.123)",

796 "trunc(-123.123)",

797 "ceil(123.123)",

798 "ceil(-123.123)",

799 "sqrt(1764)",

800 "isnan(sqrt(-1))",

801 "not(1)",

802 "not(NAN)",

803 "not(0)",

804 "6.0206dB",

805 "-3.0103dB",

806 "pow(0,1.23)",

807 "pow(PI,1.23)",

808 "PI^1.23",

809 "pow(-1,1.23)",

810 "if(1, 2)",

811 "if(1, 1, 2)",

812 "if(0, 1, 2)",

813 "ifnot(0, 23)",

814 "ifnot(1, NaN) + if(0, 1)",

815 "ifnot(1, 1, 2)",

816 "ifnot(0, 1, 2)",

817 "taylor(1, 1)",

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

819 "root(sin(ld(0))-1, 2)",

820 "root(sin(ld(0))+6+sin(ld(0)/12)-log(ld(0)), 100)",

821 "7000000B*random(0)",

822 "squish(2)",

823 "gauss(0.1)",

824 "hypot(4,3)",

825 "gcd(30,55)*print(min(9,1))",

826 "bitor(42, 12)",

827 "bitand(42, 12)",

828 "bitand(NAN, 1)",

829 "between(10, -3, 10)",

830 "between(-4, -2, -1)",

831 "between(1,2)",

832 NULL

833 };

834

835 for (expr = exprs; *expr; expr++) {

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

837 av_expr_parse_and_eval(&d, *expr,

838 const_names, const_values,

839 NULL, NULL, NULL, NULL, NULL, 0, NULL);

840 if (isnan(d))

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

842 else

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

844 }

845

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

847 const_names, const_values,

848 NULL, NULL, NULL, NULL, NULL, 0, NULL);

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

850 av_expr_parse_and_eval(&d, "80G/80Gi",

851 const_names, const_values,

852 NULL, NULL, NULL, NULL, NULL, 0, NULL);

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

854

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

856 for (i = 0; i < 1050; i++) {

857 START_TIMER;

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

859 const_names, const_values,

860 NULL, NULL, NULL, NULL, NULL, 0, NULL);

861 STOP_TIMER("av_expr_parse_and_eval");

862 }

863 }

864

865 return 0;

866 }

867 #endif

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