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 "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"

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;

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

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 };

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 };

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

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