Do not include log.h in avutil.h
[libav.git] / libavutil / eval.c
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 Libav.
6 *
7 * Libav 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 * Libav 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 Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file
24 * simple arithmetic expression evaluator.
25 *
26 * see http://joe.hotchkiss.com/programming/eval/eval.html
27 */
28
29 #include "avutil.h"
30 #include "eval.h"
31 #include "log.h"
32
33 typedef struct Parser {
34 const AVClass *class;
35 int stack_index;
36 char *s;
37 const double *const_values;
38 const char * const *const_names; // NULL terminated
39 double (* const *funcs1)(void *, double a); // NULL terminated
40 const char * const *func1_names; // NULL terminated
41 double (* const *funcs2)(void *, double a, double b); // NULL terminated
42 const char * const *func2_names; // NULL terminated
43 void *opaque;
44 int log_offset;
45 void *log_ctx;
46 #define VARS 10
47 double var[VARS];
48 } Parser;
49
50 static const AVClass class = { "Eval", av_default_item_name, NULL, LIBAVUTIL_VERSION_INT, offsetof(Parser,log_offset), offsetof(Parser,log_ctx) };
51
52 static const int8_t si_prefixes['z' - 'E' + 1] = {
53 ['y'-'E']= -24,
54 ['z'-'E']= -21,
55 ['a'-'E']= -18,
56 ['f'-'E']= -15,
57 ['p'-'E']= -12,
58 ['n'-'E']= - 9,
59 ['u'-'E']= - 6,
60 ['m'-'E']= - 3,
61 ['c'-'E']= - 2,
62 ['d'-'E']= - 1,
63 ['h'-'E']= 2,
64 ['k'-'E']= 3,
65 ['K'-'E']= 3,
66 ['M'-'E']= 6,
67 ['G'-'E']= 9,
68 ['T'-'E']= 12,
69 ['P'-'E']= 15,
70 ['E'-'E']= 18,
71 ['Z'-'E']= 21,
72 ['Y'-'E']= 24,
73 };
74
75 double av_strtod(const char *numstr, char **tail)
76 {
77 double d;
78 char *next;
79 d = strtod(numstr, &next);
80 /* if parsing succeeded, check for and interpret postfixes */
81 if (next!=numstr) {
82 if (*next >= 'E' && *next <= 'z') {
83 int e= si_prefixes[*next - 'E'];
84 if (e) {
85 if (next[1] == 'i') {
86 d*= pow( 2, e/0.3);
87 next+=2;
88 } else {
89 d*= pow(10, e);
90 next++;
91 }
92 }
93 }
94
95 if (*next=='B') {
96 d*=8;
97 next++;
98 }
99 }
100 /* if requested, fill in tail with the position after the last parsed
101 character */
102 if (tail)
103 *tail = next;
104 return d;
105 }
106
107 #define IS_IDENTIFIER_CHAR(c) ((c) - '0' <= 9U || (c) - 'a' <= 25U || (c) - 'A' <= 25U || (c) == '_')
108
109 static int strmatch(const char *s, const char *prefix)
110 {
111 int i;
112 for (i=0; prefix[i]; i++) {
113 if (prefix[i] != s[i]) return 0;
114 }
115 /* return 1 only if the s identifier is terminated */
116 return !IS_IDENTIFIER_CHAR(s[i]);
117 }
118
119 struct AVExpr {
120 enum {
121 e_value, e_const, e_func0, e_func1, e_func2,
122 e_squish, e_gauss, e_ld, e_isnan,
123 e_mod, e_max, e_min, e_eq, e_gt, e_gte,
124 e_pow, e_mul, e_div, e_add,
125 e_last, e_st, e_while, e_floor, e_ceil, e_trunc,
126 } type;
127 double value; // is sign in other types
128 union {
129 int const_index;
130 double (*func0)(double);
131 double (*func1)(void *, double);
132 double (*func2)(void *, double, double);
133 } a;
134 struct AVExpr *param[2];
135 };
136
137 static double eval_expr(Parser *p, AVExpr *e)
138 {
139 switch (e->type) {
140 case e_value: return e->value;
141 case e_const: return e->value * p->const_values[e->a.const_index];
142 case e_func0: return e->value * e->a.func0(eval_expr(p, e->param[0]));
143 case e_func1: return e->value * e->a.func1(p->opaque, eval_expr(p, e->param[0]));
144 case e_func2: return e->value * e->a.func2(p->opaque, eval_expr(p, e->param[0]), eval_expr(p, e->param[1]));
145 case e_squish: return 1/(1+exp(4*eval_expr(p, e->param[0])));
146 case e_gauss: { double d = eval_expr(p, e->param[0]); return exp(-d*d/2)/sqrt(2*M_PI); }
147 case e_ld: return e->value * p->var[av_clip(eval_expr(p, e->param[0]), 0, VARS-1)];
148 case e_isnan: return e->value * !!isnan(eval_expr(p, e->param[0]));
149 case e_floor: return e->value * floor(eval_expr(p, e->param[0]));
150 case e_ceil : return e->value * ceil (eval_expr(p, e->param[0]));
151 case e_trunc: return e->value * trunc(eval_expr(p, e->param[0]));
152 case e_while: {
153 double d = NAN;
154 while (eval_expr(p, e->param[0]))
155 d=eval_expr(p, e->param[1]);
156 return d;
157 }
158 default: {
159 double d = eval_expr(p, e->param[0]);
160 double d2 = eval_expr(p, e->param[1]);
161 switch (e->type) {
162 case e_mod: return e->value * (d - floor(d/d2)*d2);
163 case e_max: return e->value * (d > d2 ? d : d2);
164 case e_min: return e->value * (d < d2 ? d : d2);
165 case e_eq: return e->value * (d == d2 ? 1.0 : 0.0);
166 case e_gt: return e->value * (d > d2 ? 1.0 : 0.0);
167 case e_gte: return e->value * (d >= d2 ? 1.0 : 0.0);
168 case e_pow: return e->value * pow(d, d2);
169 case e_mul: return e->value * (d * d2);
170 case e_div: return e->value * (d / d2);
171 case e_add: return e->value * (d + d2);
172 case e_last:return e->value * d2;
173 case e_st : return e->value * (p->var[av_clip(d, 0, VARS-1)]= d2);
174 }
175 }
176 }
177 return NAN;
178 }
179
180 static int parse_expr(AVExpr **e, Parser *p);
181
182 void av_expr_free(AVExpr *e)
183 {
184 if (!e) return;
185 av_expr_free(e->param[0]);
186 av_expr_free(e->param[1]);
187 av_freep(&e);
188 }
189
190 static int parse_primary(AVExpr **e, Parser *p)
191 {
192 AVExpr *d = av_mallocz(sizeof(AVExpr));
193 char *next = p->s, *s0 = p->s;
194 int ret, i;
195
196 if (!d)
197 return AVERROR(ENOMEM);
198
199 /* number */
200 d->value = av_strtod(p->s, &next);
201 if (next != p->s) {
202 d->type = e_value;
203 p->s= next;
204 *e = d;
205 return 0;
206 }
207 d->value = 1;
208
209 /* named constants */
210 for (i=0; p->const_names && p->const_names[i]; i++) {
211 if (strmatch(p->s, p->const_names[i])) {
212 p->s+= strlen(p->const_names[i]);
213 d->type = e_const;
214 d->a.const_index = i;
215 *e = d;
216 return 0;
217 }
218 }
219
220 p->s= strchr(p->s, '(');
221 if (p->s==NULL) {
222 av_log(p, AV_LOG_ERROR, "Undefined constant or missing '(' in '%s'\n", s0);
223 p->s= next;
224 av_expr_free(d);
225 return AVERROR(EINVAL);
226 }
227 p->s++; // "("
228 if (*next == '(') { // special case do-nothing
229 av_freep(&d);
230 if ((ret = parse_expr(&d, p)) < 0)
231 return ret;
232 if (p->s[0] != ')') {
233 av_log(p, AV_LOG_ERROR, "Missing ')' in '%s'\n", s0);
234 av_expr_free(d);
235 return AVERROR(EINVAL);
236 }
237 p->s++; // ")"
238 *e = d;
239 return 0;
240 }
241 if ((ret = parse_expr(&(d->param[0]), p)) < 0) {
242 av_expr_free(d);
243 return ret;
244 }
245 if (p->s[0]== ',') {
246 p->s++; // ","
247 parse_expr(&d->param[1], p);
248 }
249 if (p->s[0] != ')') {
250 av_log(p, AV_LOG_ERROR, "Missing ')' or too many args in '%s'\n", s0);
251 av_expr_free(d);
252 return AVERROR(EINVAL);
253 }
254 p->s++; // ")"
255
256 d->type = e_func0;
257 if (strmatch(next, "sinh" )) d->a.func0 = sinh;
258 else if (strmatch(next, "cosh" )) d->a.func0 = cosh;
259 else if (strmatch(next, "tanh" )) d->a.func0 = tanh;
260 else if (strmatch(next, "sin" )) d->a.func0 = sin;
261 else if (strmatch(next, "cos" )) d->a.func0 = cos;
262 else if (strmatch(next, "tan" )) d->a.func0 = tan;
263 else if (strmatch(next, "atan" )) d->a.func0 = atan;
264 else if (strmatch(next, "asin" )) d->a.func0 = asin;
265 else if (strmatch(next, "acos" )) d->a.func0 = acos;
266 else if (strmatch(next, "exp" )) d->a.func0 = exp;
267 else if (strmatch(next, "log" )) d->a.func0 = log;
268 else if (strmatch(next, "abs" )) d->a.func0 = fabs;
269 else if (strmatch(next, "squish")) d->type = e_squish;
270 else if (strmatch(next, "gauss" )) d->type = e_gauss;
271 else if (strmatch(next, "mod" )) d->type = e_mod;
272 else if (strmatch(next, "max" )) d->type = e_max;
273 else if (strmatch(next, "min" )) d->type = e_min;
274 else if (strmatch(next, "eq" )) d->type = e_eq;
275 else if (strmatch(next, "gte" )) d->type = e_gte;
276 else if (strmatch(next, "gt" )) d->type = e_gt;
277 else if (strmatch(next, "lte" )) { AVExpr *tmp = d->param[1]; d->param[1] = d->param[0]; d->param[0] = tmp; d->type = e_gt; }
278 else if (strmatch(next, "lt" )) { AVExpr *tmp = d->param[1]; d->param[1] = d->param[0]; d->param[0] = tmp; d->type = e_gte; }
279 else if (strmatch(next, "ld" )) d->type = e_ld;
280 else if (strmatch(next, "isnan" )) d->type = e_isnan;
281 else if (strmatch(next, "st" )) d->type = e_st;
282 else if (strmatch(next, "while" )) d->type = e_while;
283 else if (strmatch(next, "floor" )) d->type = e_floor;
284 else if (strmatch(next, "ceil" )) d->type = e_ceil;
285 else if (strmatch(next, "trunc" )) d->type = e_trunc;
286 else {
287 for (i=0; p->func1_names && p->func1_names[i]; i++) {
288 if (strmatch(next, p->func1_names[i])) {
289 d->a.func1 = p->funcs1[i];
290 d->type = e_func1;
291 *e = d;
292 return 0;
293 }
294 }
295
296 for (i=0; p->func2_names && p->func2_names[i]; i++) {
297 if (strmatch(next, p->func2_names[i])) {
298 d->a.func2 = p->funcs2[i];
299 d->type = e_func2;
300 *e = d;
301 return 0;
302 }
303 }
304
305 av_log(p, AV_LOG_ERROR, "Unknown function in '%s'\n", s0);
306 av_expr_free(d);
307 return AVERROR(EINVAL);
308 }
309
310 *e = d;
311 return 0;
312 }
313
314 static AVExpr *new_eval_expr(int type, int value, AVExpr *p0, AVExpr *p1)
315 {
316 AVExpr *e = av_mallocz(sizeof(AVExpr));
317 if (!e)
318 return NULL;
319 e->type =type ;
320 e->value =value ;
321 e->param[0] =p0 ;
322 e->param[1] =p1 ;
323 return e;
324 }
325
326 static int parse_pow(AVExpr **e, Parser *p, int *sign)
327 {
328 *sign= (*p->s == '+') - (*p->s == '-');
329 p->s += *sign&1;
330 return parse_primary(e, p);
331 }
332
333 static int parse_factor(AVExpr **e, Parser *p)
334 {
335 int sign, sign2, ret;
336 AVExpr *e0, *e1, *e2;
337 if ((ret = parse_pow(&e0, p, &sign)) < 0)
338 return ret;
339 while(p->s[0]=='^'){
340 e1 = e0;
341 p->s++;
342 if ((ret = parse_pow(&e2, p, &sign2)) < 0) {
343 av_expr_free(e1);
344 return ret;
345 }
346 e0 = new_eval_expr(e_pow, 1, e1, e2);
347 if (!e0) {
348 av_expr_free(e1);
349 av_expr_free(e2);
350 return AVERROR(ENOMEM);
351 }
352 if (e0->param[1]) e0->param[1]->value *= (sign2|1);
353 }
354 if (e0) e0->value *= (sign|1);
355
356 *e = e0;
357 return 0;
358 }
359
360 static int parse_term(AVExpr **e, Parser *p)
361 {
362 int ret;
363 AVExpr *e0, *e1, *e2;
364 if ((ret = parse_factor(&e0, p)) < 0)
365 return ret;
366 while (p->s[0]=='*' || p->s[0]=='/') {
367 int c= *p->s++;
368 e1 = e0;
369 if ((ret = parse_factor(&e2, p)) < 0) {
370 av_expr_free(e1);
371 return ret;
372 }
373 e0 = new_eval_expr(c == '*' ? e_mul : e_div, 1, e1, e2);
374 if (!e0) {
375 av_expr_free(e1);
376 av_expr_free(e2);
377 return AVERROR(ENOMEM);
378 }
379 }
380 *e = e0;
381 return 0;
382 }
383
384 static int parse_subexpr(AVExpr **e, Parser *p)
385 {
386 int ret;
387 AVExpr *e0, *e1, *e2;
388 if ((ret = parse_term(&e0, p)) < 0)
389 return ret;
390 while (*p->s == '+' || *p->s == '-') {
391 e1 = e0;
392 if ((ret = parse_term(&e2, p)) < 0) {
393 av_expr_free(e1);
394 return ret;
395 }
396 e0 = new_eval_expr(e_add, 1, e1, e2);
397 if (!e0) {
398 av_expr_free(e1);
399 av_expr_free(e2);
400 return AVERROR(ENOMEM);
401 }
402 };
403
404 *e = e0;
405 return 0;
406 }
407
408 static int parse_expr(AVExpr **e, Parser *p)
409 {
410 int ret;
411 AVExpr *e0, *e1, *e2;
412 if (p->stack_index <= 0) //protect against stack overflows
413 return AVERROR(EINVAL);
414 p->stack_index--;
415
416 if ((ret = parse_subexpr(&e0, p)) < 0)
417 return ret;
418 while (*p->s == ';') {
419 p->s++;
420 e1 = e0;
421 if ((ret = parse_subexpr(&e2, p)) < 0) {
422 av_expr_free(e1);
423 return ret;
424 }
425 e0 = new_eval_expr(e_last, 1, e1, e2);
426 if (!e0) {
427 av_expr_free(e1);
428 av_expr_free(e2);
429 return AVERROR(ENOMEM);
430 }
431 };
432
433 p->stack_index++;
434 *e = e0;
435 return 0;
436 }
437
438 static int verify_expr(AVExpr *e)
439 {
440 if (!e) return 0;
441 switch (e->type) {
442 case e_value:
443 case e_const: return 1;
444 case e_func0:
445 case e_func1:
446 case e_squish:
447 case e_ld:
448 case e_gauss:
449 case e_isnan:
450 case e_floor:
451 case e_ceil:
452 case e_trunc:
453 return verify_expr(e->param[0]);
454 default: return verify_expr(e->param[0]) && verify_expr(e->param[1]);
455 }
456 }
457
458 int av_expr_parse(AVExpr **expr, const char *s,
459 const char * const *const_names,
460 const char * const *func1_names, double (* const *funcs1)(void *, double),
461 const char * const *func2_names, double (* const *funcs2)(void *, double, double),
462 int log_offset, void *log_ctx)
463 {
464 Parser p;
465 AVExpr *e = NULL;
466 char *w = av_malloc(strlen(s) + 1);
467 char *wp = w;
468 const char *s0 = s;
469 int ret = 0;
470
471 if (!w)
472 return AVERROR(ENOMEM);
473
474 while (*s)
475 if (!isspace(*s++)) *wp++ = s[-1];
476 *wp++ = 0;
477
478 p.class = &class;
479 p.stack_index=100;
480 p.s= w;
481 p.const_names = const_names;
482 p.funcs1 = funcs1;
483 p.func1_names = func1_names;
484 p.funcs2 = funcs2;
485 p.func2_names = func2_names;
486 p.log_offset = log_offset;
487 p.log_ctx = log_ctx;
488
489 if ((ret = parse_expr(&e, &p)) < 0)
490 goto end;
491 if (*p.s) {
492 av_log(&p, AV_LOG_ERROR, "Invalid chars '%s' at the end of expression '%s'\n", p.s, s0);
493 ret = AVERROR(EINVAL);
494 goto end;
495 }
496 if (!verify_expr(e)) {
497 av_expr_free(e);
498 ret = AVERROR(EINVAL);
499 goto end;
500 }
501 *expr = e;
502 end:
503 av_free(w);
504 return ret;
505 }
506
507 double av_expr_eval(AVExpr *e, const double *const_values, void *opaque)
508 {
509 Parser p;
510
511 p.const_values = const_values;
512 p.opaque = opaque;
513 return eval_expr(&p, e);
514 }
515
516 int av_expr_parse_and_eval(double *d, const char *s,
517 const char * const *const_names, const double *const_values,
518 const char * const *func1_names, double (* const *funcs1)(void *, double),
519 const char * const *func2_names, double (* const *funcs2)(void *, double, double),
520 void *opaque, int log_offset, void *log_ctx)
521 {
522 AVExpr *e = NULL;
523 int ret = av_expr_parse(&e, s, const_names, func1_names, funcs1, func2_names, funcs2, log_offset, log_ctx);
524
525 if (ret < 0) {
526 *d = NAN;
527 return ret;
528 }
529 *d = av_expr_eval(e, const_values, opaque);
530 av_expr_free(e);
531 return isnan(*d) ? AVERROR(EINVAL) : 0;
532 }
533
534 #ifdef TEST
535 #undef printf
536 static double const_values[] = {
537 M_PI,
538 M_E,
539 0
540 };
541
542 static const char *const_names[] = {
543 "PI",
544 "E",
545 0
546 };
547
548 int main(void)
549 {
550 int i;
551 double d;
552 const char **expr, *exprs[] = {
553 "",
554 "1;2",
555 "-20",
556 "-PI",
557 "+PI",
558 "1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)",
559 "80G/80Gi"
560 "1k",
561 "1Gi",
562 "1gi",
563 "1GiFoo",
564 "1k+1k",
565 "1Gi*3foo",
566 "foo",
567 "foo(",
568 "foo()",
569 "foo)",
570 "sin",
571 "sin(",
572 "sin()",
573 "sin)",
574 "sin 10",
575 "sin(1,2,3)",
576 "sin(1 )",
577 "1",
578 "1foo",
579 "bar + PI + E + 100f*2 + foo",
580 "13k + 12f - foo(1, 2)",
581 "1gi",
582 "1Gi",
583 "st(0, 123)",
584 "st(1, 123); ld(1)",
585 /* compute 1+2+...+N */
586 "st(0, 1); while(lte(ld(0), 100), st(1, ld(1)+ld(0));st(0, ld(0)+1)); ld(1)",
587 /* compute Fib(N) */
588 "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)",
589 "while(0, 10)",
590 "st(0, 1); while(lte(ld(0),100), st(1, ld(1)+ld(0)); st(0, ld(0)+1))",
591 "isnan(1)",
592 "isnan(NAN)",
593 "floor(NAN)",
594 "floor(123.123)",
595 "floor(-123.123)",
596 "trunc(123.123)",
597 "trunc(-123.123)",
598 "ceil(123.123)",
599 "ceil(-123.123)",
600 NULL
601 };
602
603 for (expr = exprs; *expr; expr++) {
604 printf("Evaluating '%s'\n", *expr);
605 av_expr_parse_and_eval(&d, *expr,
606 const_names, const_values,
607 NULL, NULL, NULL, NULL, NULL, 0, NULL);
608 printf("'%s' -> %f\n\n", *expr, d);
609 }
610
611 av_expr_parse_and_eval(&d, "1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)",
612 const_names, const_values,
613 NULL, NULL, NULL, NULL, NULL, 0, NULL);
614 printf("%f == 12.7\n", d);
615 av_expr_parse_and_eval(&d, "80G/80Gi",
616 const_names, const_values,
617 NULL, NULL, NULL, NULL, NULL, 0, NULL);
618 printf("%f == 0.931322575\n", d);
619
620 for (i=0; i<1050; i++) {
621 START_TIMER
622 av_expr_parse_and_eval(&d, "1+(5-2)^(3-1)+1/2+sin(PI)-max(-2.2,-3.1)",
623 const_names, const_values,
624 NULL, NULL, NULL, NULL, NULL, 0, NULL);
625 STOP_TIMER("av_expr_parse_and_eval")
626 }
627 return 0;
628 }
629 #endif