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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 "ffmath.h"
35#include "internal.h"
36#include "log.h"
37#include "mathematics.h"
38#include "time.h"
39#include "avstring.h"
40#include "timer.h"
41#include "reverse.h"
42
43typedef struct Parser {
44 const AVClass *class;
45 int stack_index;
46 char *s;
47 const double *const_values;
48 const char * const *const_names; // NULL terminated
49 double (* const *funcs1)(void *, double a); // NULL terminated
50 const char * const *func1_names; // NULL terminated
51 double (* const *funcs2)(void *, double a, double b); // NULL terminated
52 const char * const *func2_names; // NULL terminated
53 void *opaque;
54 int log_offset;
55 void *log_ctx;
56#define VARS 10
57 double *var;
58} Parser;
59
60static const AVClass eval_class = { "Eval", av_default_item_name, NULL, LIBAVUTIL_VERSION_INT, offsetof(Parser,log_offset), offsetof(Parser,log_ctx) };
61
62static const struct {
63 double bin_val;
64 double dec_val;
65 int8_t exp;
66} si_prefixes['z' - 'E' + 1] = {
67 ['y'-'E']= { 8.271806125530276749e-25, 1e-24, -24 },
68 ['z'-'E']= { 8.4703294725430034e-22, 1e-21, -21 },
69 ['a'-'E']= { 8.6736173798840355e-19, 1e-18, -18 },
70 ['f'-'E']= { 8.8817841970012523e-16, 1e-15, -15 },
71 ['p'-'E']= { 9.0949470177292824e-13, 1e-12, -12 },
72 ['n'-'E']= { 9.3132257461547852e-10, 1e-9, -9 },
73 ['u'-'E']= { 9.5367431640625e-7, 1e-6, -6 },
74 ['m'-'E']= { 9.765625e-4, 1e-3, -3 },
75 ['c'-'E']= { 9.8431332023036951e-3, 1e-2, -2 },
76 ['d'-'E']= { 9.921256574801246e-2, 1e-1, -1 },
77 ['h'-'E']= { 1.0159366732596479e2, 1e2, 2 },
78 ['k'-'E']= { 1.024e3, 1e3, 3 },
79 ['K'-'E']= { 1.024e3, 1e3, 3 },
80 ['M'-'E']= { 1.048576e6, 1e6, 6 },
81 ['G'-'E']= { 1.073741824e9, 1e9, 9 },
82 ['T'-'E']= { 1.099511627776e12, 1e12, 12 },
83 ['P'-'E']= { 1.125899906842624e15, 1e15, 15 },
84 ['E'-'E']= { 1.152921504606847e18, 1e18, 18 },
85 ['Z'-'E']= { 1.1805916207174113e21, 1e21, 21 },
86 ['Y'-'E']= { 1.2089258196146292e24, 1e24, 24 },
87};
88
89static const struct {
90 const char *name;
91 double value;
92} constants[] = {
93 { "E", M_E },
94 { "PI", M_PI },
95 { "PHI", M_PHI },
96 { "QP2LAMBDA", FF_QP2LAMBDA },
97};
98
99double av_strtod(const char *numstr, char **tail)
100{
101 double d;
102 char *next;
103 if(numstr[0]=='0' && (numstr[1]|0x20)=='x') {
104 d = strtoul(numstr, &next, 16);
105 } else
106 d = strtod(numstr, &next);
107 /* if parsing succeeded, check for and interpret postfixes */
108 if (next!=numstr) {
109 if (next[0] == 'd' && next[1] == 'B') {
110 /* treat dB as decibels instead of decibytes */
111 d = ff_exp10(d / 20);
112 next += 2;
113 } else if (*next >= 'E' && *next <= 'z') {
114 int e= si_prefixes[*next - 'E'].exp;
115 if (e) {
116 if (next[1] == 'i') {
117 d*= si_prefixes[*next - 'E'].bin_val;
118 next+=2;
119 } else {
120 d*= si_prefixes[*next - 'E'].dec_val;
121 next++;
122 }
123 }
124 }
125
126 if (*next=='B') {
127 d*=8;
128 next++;
129 }
130 }
131 /* if requested, fill in tail with the position after the last parsed
132 character */
133 if (tail)
134 *tail = next;
135 return d;
136}
137
138#define IS_IDENTIFIER_CHAR(c) ((c) - '0' <= 9U || (c) - 'a' <= 25U || (c) - 'A' <= 25U || (c) == '_')
139
140static int strmatch(const char *s, const char *prefix)
141{
142 int i;
143 for (i=0; prefix[i]; i++) {
144 if (prefix[i] != s[i]) return 0;
145 }
146 /* return 1 only if the s identifier is terminated */
147 return !IS_IDENTIFIER_CHAR(s[i]);
148}
149
150struct AVExpr {
151 enum {
152 e_value, e_const, e_func0, e_func1, e_func2,
153 e_squish, e_gauss, e_ld, e_isnan, e_isinf,
154 e_mod, e_max, e_min, e_eq, e_gt, e_gte, e_lte, e_lt,
155 e_pow, e_mul, e_div, e_add,
156 e_last, e_st, e_while, e_taylor, e_root, e_floor, e_ceil, e_trunc,
157 e_sqrt, e_not, e_random, e_hypot, e_gcd,
158 e_if, e_ifnot, e_print, e_bitand, e_bitor, e_between, e_clip, e_atan2
159 } type;
160 double value; // is sign in other types
161 union {
162 int const_index;
163 double (*func0)(double);
164 double (*func1)(void *, double);
165 double (*func2)(void *, double, double);
166 } a;
167 struct AVExpr *param[3];
168 double *var;
169};
170
171static double etime(double v)
172{
173 return av_gettime() * 0.000001;
174}
175
176static double eval_expr(Parser *p, AVExpr *e)
177{
178 switch (e->type) {
179 case e_value: return e->value;
180 case e_const: return e->value * p->const_values[e->a.const_index];
181 case e_func0: return e->value * e->a.func0(eval_expr(p, e->param[0]));
182 case e_func1: return e->value * e->a.func1(p->opaque, eval_expr(p, e->param[0]));
183 case e_func2: return e->value * e->a.func2(p->opaque, eval_expr(p, e->param[0]), eval_expr(p, e->param[1]));
184 case e_squish: return 1/(1+exp(4*eval_expr(p, e->param[0])));
185 case e_gauss: { double d = eval_expr(p, e->param[0]); return exp(-d*d/2)/sqrt(2*M_PI); }
186 case e_ld: return e->value * p->var[av_clip(eval_expr(p, e->param[0]), 0, VARS-1)];
187 case e_isnan: return e->value * !!isnan(eval_expr(p, e->param[0]));
188 case e_isinf: return e->value * !!isinf(eval_expr(p, e->param[0]));
189 case e_floor: return e->value * floor(eval_expr(p, e->param[0]));
190 case e_ceil : return e->value * ceil (eval_expr(p, e->param[0]));
191 case e_trunc: return e->value * trunc(eval_expr(p, e->param[0]));
192 case e_sqrt: return e->value * sqrt (eval_expr(p, e->param[0]));
193 case e_not: return e->value * (eval_expr(p, e->param[0]) == 0);
194 case e_if: return e->value * (eval_expr(p, e->param[0]) ? eval_expr(p, e->param[1]) :
195 e->param[2] ? eval_expr(p, e->param[2]) : 0);
196 case e_ifnot: return e->value * (!eval_expr(p, e->param[0]) ? eval_expr(p, e->param[1]) :
197 e->param[2] ? eval_expr(p, e->param[2]) : 0);
198 case e_clip: {
199 double x = eval_expr(p, e->param[0]);
200 double min = eval_expr(p, e->param[1]), max = eval_expr(p, e->param[2]);
201 if (isnan(min) || isnan(max) || isnan(x) || min > max)
202 return NAN;
203 return e->value * av_clipd(eval_expr(p, e->param[0]), min, max);
204 }
205 case e_between: {
206 double d = eval_expr(p, e->param[0]);
207 return e->value * (d >= eval_expr(p, e->param[1]) &&
208 d <= eval_expr(p, e->param[2]));
209 }
210 case e_print: {
211 double x = eval_expr(p, e->param[0]);
212 int level = e->param[1] ? av_clip(eval_expr(p, e->param[1]), INT_MIN, INT_MAX) : AV_LOG_INFO;
213 av_log(p, level, "%f\n", x);
214 return x;
215 }
216 case e_random:{
217 int idx= av_clip(eval_expr(p, e->param[0]), 0, VARS-1);
218 uint64_t r= isnan(p->var[idx]) ? 0 : p->var[idx];
219 r= r*1664525+1013904223;
220 p->var[idx]= r;
221 return e->value * (r * (1.0/UINT64_MAX));
222 }
223 case e_while: {
224 double d = NAN;
225 while (eval_expr(p, e->param[0]))
226 d=eval_expr(p, e->param[1]);
227 return d;
228 }
229 case e_taylor: {
230 double t = 1, d = 0, v;
231 double x = eval_expr(p, e->param[1]);
232 int id = e->param[2] ? av_clip(eval_expr(p, e->param[2]), 0, VARS-1) : 0;
233 int i;
234 double var0 = p->var[id];
235 for(i=0; i<1000; i++) {
236 double ld = d;
237 p->var[id] = i;
238 v = eval_expr(p, e->param[0]);
239 d += t*v;
240 if(ld==d && v)
241 break;
242 t *= x / (i+1);
243 }
244 p->var[id] = var0;
245 return d;
246 }
247 case e_root: {
248 int i, j;
249 double low = -1, high = -1, v, low_v = -DBL_MAX, high_v = DBL_MAX;
250 double var0 = p->var[0];
251 double x_max = eval_expr(p, e->param[1]);
252 for(i=-1; i<1024; i++) {
253 if(i<255) {
254 p->var[0] = ff_reverse[i&255]*x_max/255;
255 } else {
256 p->var[0] = x_max*pow(0.9, i-255);
257 if (i&1) p->var[0] *= -1;
258 if (i&2) p->var[0] += low;
259 else p->var[0] += high;
260 }
261 v = eval_expr(p, e->param[0]);
262 if (v<=0 && v>low_v) {
263 low = p->var[0];
264 low_v = v;
265 }
266 if (v>=0 && v<high_v) {
267 high = p->var[0];
268 high_v = v;
269 }
270 if (low>=0 && high>=0){
271 for (j=0; j<1000; j++) {
272 p->var[0] = (low+high)*0.5;
273 if (low == p->var[0] || high == p->var[0])
274 break;
275 v = eval_expr(p, e->param[0]);
276 if (v<=0) low = p->var[0];
277 if (v>=0) high= p->var[0];
278 if (isnan(v)) {
279 low = high = v;
280 break;
281 }
282 }
283 break;
284 }
285 }
286 p->var[0] = var0;
287 return -low_v<high_v ? low : high;
288 }
289 default: {
290 double d = eval_expr(p, e->param[0]);
291 double d2 = eval_expr(p, e->param[1]);
292 switch (e->type) {
293 case e_mod: return e->value * (d - floor((!CONFIG_FTRAPV || d2) ? d / d2 : d * INFINITY) * d2);
294 case e_gcd: return e->value * av_gcd(d,d2);
295 case e_max: return e->value * (d > d2 ? d : d2);
296 case e_min: return e->value * (d < d2 ? d : d2);
297 case e_eq: return e->value * (d == d2 ? 1.0 : 0.0);
298 case e_gt: return e->value * (d > d2 ? 1.0 : 0.0);
299 case e_gte: return e->value * (d >= d2 ? 1.0 : 0.0);
300 case e_lt: return e->value * (d < d2 ? 1.0 : 0.0);
301 case e_lte: return e->value * (d <= d2 ? 1.0 : 0.0);
302 case e_pow: return e->value * pow(d, d2);
303 case e_mul: return e->value * (d * d2);
304 case e_div: return e->value * ((!CONFIG_FTRAPV || d2 ) ? (d / d2) : d * INFINITY);
305 case e_add: return e->value * (d + d2);
306 case e_last:return e->value * d2;
307 case e_st : return e->value * (p->var[av_clip(d, 0, VARS-1)]= d2);
308 case e_hypot:return e->value * hypot(d, d2);
309 case e_atan2:return e->value * atan2(d, d2);
310 case e_bitand: return isnan(d) || isnan(d2) ? NAN : e->value * ((long int)d & (long int)d2);
311 case e_bitor: return isnan(d) || isnan(d2) ? NAN : e->value * ((long int)d | (long int)d2);
312 }
313 }
314 }
315 return NAN;
316}
317
318static int parse_expr(AVExpr **e, Parser *p);
319
320void av_expr_free(AVExpr *e)
321{
322 if (!e) return;
323 av_expr_free(e->param[0]);
324 av_expr_free(e->param[1]);
325 av_expr_free(e->param[2]);
326 av_freep(&e->var);
327 av_freep(&e);
328}
329
330static int parse_primary(AVExpr **e, Parser *p)
331{
332 AVExpr *d = av_mallocz(sizeof(AVExpr));
333 char *next = p->s, *s0 = p->s;
334 int ret, i;
335
336 if (!d)
337 return AVERROR(ENOMEM);
338
339 /* number */
340 d->value = av_strtod(p->s, &next);
341 if (next != p->s) {
342 d->type = e_value;
343 p->s= next;
344 *e = d;
345 return 0;
346 }
347 d->value = 1;
348
349 /* named constants */
350 for (i=0; p->const_names && p->const_names[i]; i++) {
351 if (strmatch(p->s, p->const_names[i])) {
352 p->s+= strlen(p->const_names[i]);
353 d->type = e_const;
354 d->a.const_index = i;
355 *e = d;
356 return 0;
357 }
358 }
359 for (i = 0; i < FF_ARRAY_ELEMS(constants); i++) {
360 if (strmatch(p->s, constants[i].name)) {
361 p->s += strlen(constants[i].name);
362 d->type = e_value;
363 d->value = constants[i].value;
364 *e = d;
365 return 0;
366 }
367 }
368
369 p->s= strchr(p->s, '(');
370 if (!p->s) {
371 av_log(p, AV_LOG_ERROR, "Undefined constant or missing '(' in '%s'\n", s0);
372 p->s= next;
373 av_expr_free(d);
374 return AVERROR(EINVAL);
375 }
376 p->s++; // "("
377 if (*next == '(') { // special case do-nothing
378 av_freep(&d);
379 if ((ret = parse_expr(&d, p)) < 0)
380 return ret;
381 if (p->s[0] != ')') {
382 av_log(p, AV_LOG_ERROR, "Missing ')' in '%s'\n", s0);
383 av_expr_free(d);
384 return AVERROR(EINVAL);
385 }
386 p->s++; // ")"
387 *e = d;
388 return 0;
389 }
390 if ((ret = parse_expr(&(d->param[0]), p)) < 0) {
391 av_expr_free(d);
392 return ret;
393 }
394 if (p->s[0]== ',') {
395 p->s++; // ","
396 parse_expr(&d->param[1], p);
397 }
398 if (p->s[0]== ',') {
399 p->s++; // ","
400 parse_expr(&d->param[2], p);
401 }
402 if (p->s[0] != ')') {
403 av_log(p, AV_LOG_ERROR, "Missing ')' or too many args in '%s'\n", s0);
404 av_expr_free(d);
405 return AVERROR(EINVAL);
406 }
407 p->s++; // ")"
408
409 d->type = e_func0;
410 if (strmatch(next, "sinh" )) d->a.func0 = sinh;
411 else if (strmatch(next, "cosh" )) d->a.func0 = cosh;
412 else if (strmatch(next, "tanh" )) d->a.func0 = tanh;
413 else if (strmatch(next, "sin" )) d->a.func0 = sin;
414 else if (strmatch(next, "cos" )) d->a.func0 = cos;
415 else if (strmatch(next, "tan" )) d->a.func0 = tan;
416 else if (strmatch(next, "atan" )) d->a.func0 = atan;
417 else if (strmatch(next, "asin" )) d->a.func0 = asin;
418 else if (strmatch(next, "acos" )) d->a.func0 = acos;
419 else if (strmatch(next, "exp" )) d->a.func0 = exp;
420 else if (strmatch(next, "log" )) d->a.func0 = log;
421 else if (strmatch(next, "abs" )) d->a.func0 = fabs;
422 else if (strmatch(next, "time" )) d->a.func0 = etime;
423 else if (strmatch(next, "squish")) d->type = e_squish;
424 else if (strmatch(next, "gauss" )) d->type = e_gauss;
425 else if (strmatch(next, "mod" )) d->type = e_mod;
426 else if (strmatch(next, "max" )) d->type = e_max;
427 else if (strmatch(next, "min" )) d->type = e_min;
428 else if (strmatch(next, "eq" )) d->type = e_eq;
429 else if (strmatch(next, "gte" )) d->type = e_gte;
430 else if (strmatch(next, "gt" )) d->type = e_gt;
431 else if (strmatch(next, "lte" )) d->type = e_lte;
432 else if (strmatch(next, "lt" )) d->type = e_lt;
433 else if (strmatch(next, "ld" )) d->type = e_ld;
434 else if (strmatch(next, "isnan" )) d->type = e_isnan;
435 else if (strmatch(next, "isinf" )) d->type = e_isinf;
436 else if (strmatch(next, "st" )) d->type = e_st;
437 else if (strmatch(next, "while" )) d->type = e_while;
438 else if (strmatch(next, "taylor")) d->type = e_taylor;
439 else if (strmatch(next, "root" )) d->type = e_root;
440 else if (strmatch(next, "floor" )) d->type = e_floor;
441 else if (strmatch(next, "ceil" )) d->type = e_ceil;
442 else if (strmatch(next, "trunc" )) d->type = e_trunc;
443 else if (strmatch(next, "sqrt" )) d->type = e_sqrt;
444 else if (strmatch(next, "not" )) d->type = e_not;
445 else if (strmatch(next, "pow" )) d->type = e_pow;
446 else if (strmatch(next, "print" )) d->type = e_print;
447 else if (strmatch(next, "random")) d->type = e_random;
448 else if (strmatch(next, "hypot" )) d->type = e_hypot;
449 else if (strmatch(next, "gcd" )) d->type = e_gcd;
450 else if (strmatch(next, "if" )) d->type = e_if;
451 else if (strmatch(next, "ifnot" )) d->type = e_ifnot;
452 else if (strmatch(next, "bitand")) d->type = e_bitand;
453 else if (strmatch(next, "bitor" )) d->type = e_bitor;
454 else if (strmatch(next, "between"))d->type = e_between;
455 else if (strmatch(next, "clip" )) d->type = e_clip;
456 else if (strmatch(next, "atan2" )) d->type = e_atan2;
457 else {
458 for (i=0; p->func1_names && p->func1_names[i]; i++) {
459 if (strmatch(next, p->func1_names[i])) {
460 d->a.func1 = p->funcs1[i];
461 d->type = e_func1;
462 *e = d;
463 return 0;
464 }
465 }
466
467 for (i=0; p->func2_names && p->func2_names[i]; i++) {
468 if (strmatch(next, p->func2_names[i])) {
469 d->a.func2 = p->funcs2[i];
470 d->type = e_func2;
471 *e = d;
472 return 0;
473 }
474 }
475
476 av_log(p, AV_LOG_ERROR, "Unknown function in '%s'\n", s0);
477 av_expr_free(d);
478 return AVERROR(EINVAL);
479 }
480
481 *e = d;
482 return 0;
483}
484
485static AVExpr *make_eval_expr(int type, int value, AVExpr *p0, AVExpr *p1)
486{
487 AVExpr *e = av_mallocz(sizeof(AVExpr));
488 if (!e)
489 return NULL;
490 e->type =type ;
491 e->value =value ;
492 e->param[0] =p0 ;
493 e->param[1] =p1 ;
494 return e;
495}
496
497static int parse_pow(AVExpr **e, Parser *p, int *sign)
498{
499 *sign= (*p->s == '+') - (*p->s == '-');
500 p->s += *sign&1;
501 return parse_primary(e, p);
502}
503
504static int parse_dB(AVExpr **e, Parser *p, int *sign)
505{
506 /* do not filter out the negative sign when parsing a dB value.
507 for example, -3dB is not the same as -(3dB) */
508 if (*p->s == '-') {
509 char *next;
510 double av_unused ignored = strtod(p->s, &next);
511 if (next != p->s && next[0] == 'd' && next[1] == 'B') {
512 *sign = 0;
513 return parse_primary(e, p);
514 }
515 }
516 return parse_pow(e, p, sign);
517}
518
519static int parse_factor(AVExpr **e, Parser *p)
520{
521 int sign, sign2, ret;
522 AVExpr *e0, *e1, *e2;
523 if ((ret = parse_dB(&e0, p, &sign)) < 0)
524 return ret;
525 while(p->s[0]=='^'){
526 e1 = e0;
527 p->s++;
528 if ((ret = parse_dB(&e2, p, &sign2)) < 0) {
529 av_expr_free(e1);
530 return ret;
531 }
532 e0 = make_eval_expr(e_pow, 1, e1, e2);
533 if (!e0) {
534 av_expr_free(e1);
535 av_expr_free(e2);
536 return AVERROR(ENOMEM);
537 }
538 if (e0->param[1]) e0->param[1]->value *= (sign2|1);
539 }
540 if (e0) e0->value *= (sign|1);
541
542 *e = e0;
543 return 0;
544}
545
546static int parse_term(AVExpr **e, Parser *p)
547{
548 int ret;
549 AVExpr *e0, *e1, *e2;
550 if ((ret = parse_factor(&e0, p)) < 0)
551 return ret;
552 while (p->s[0]=='*' || p->s[0]=='/') {
553 int c= *p->s++;
554 e1 = e0;
555 if ((ret = parse_factor(&e2, p)) < 0) {
556 av_expr_free(e1);
557 return ret;
558 }
559 e0 = make_eval_expr(c == '*' ? e_mul : e_div, 1, e1, e2);
560 if (!e0) {
561 av_expr_free(e1);
562 av_expr_free(e2);
563 return AVERROR(ENOMEM);
564 }
565 }
566 *e = e0;
567 return 0;
568}
569
570static int parse_subexpr(AVExpr **e, Parser *p)
571{
572 int ret;
573 AVExpr *e0, *e1, *e2;
574 if ((ret = parse_term(&e0, p)) < 0)
575 return ret;
576 while (*p->s == '+' || *p->s == '-') {
577 e1 = e0;
578 if ((ret = parse_term(&e2, p)) < 0) {
579 av_expr_free(e1);
580 return ret;
581 }
582 e0 = make_eval_expr(e_add, 1, e1, e2);
583 if (!e0) {
584 av_expr_free(e1);
585 av_expr_free(e2);
586 return AVERROR(ENOMEM);
587 }
588 };
589
590 *e = e0;
591 return 0;
592}
593
594static int parse_expr(AVExpr **e, Parser *p)
595{
596 int ret;
597 AVExpr *e0, *e1, *e2;
598 if (p->stack_index <= 0) //protect against stack overflows
599 return AVERROR(EINVAL);
600 p->stack_index--;
601
602 if ((ret = parse_subexpr(&e0, p)) < 0)
603 return ret;
604 while (*p->s == ';') {
605 p->s++;
606 e1 = e0;
607 if ((ret = parse_subexpr(&e2, p)) < 0) {
608 av_expr_free(e1);
609 return ret;
610 }
611 e0 = make_eval_expr(e_last, 1, e1, e2);
612 if (!e0) {
613 av_expr_free(e1);
614 av_expr_free(e2);
615 return AVERROR(ENOMEM);
616 }
617 };
618
619 p->stack_index++;
620 *e = e0;
621 return 0;
622}
623
624static int verify_expr(AVExpr *e)
625{
626 if (!e) return 0;
627 switch (e->type) {
628 case e_value:
629 case e_const: return 1;
630 case e_func0:
631 case e_func1:
632 case e_squish:
633 case e_ld:
634 case e_gauss:
635 case e_isnan:
636 case e_isinf:
637 case e_floor:
638 case e_ceil:
639 case e_trunc:
640 case e_sqrt:
641 case e_not:
642 case e_random:
643 return verify_expr(e->param[0]) && !e->param[1];
644 case e_print:
645 return verify_expr(e->param[0])
646 && (!e->param[1] || verify_expr(e->param[1]));
647 case e_if:
648 case e_ifnot:
649 case e_taylor:
650 return verify_expr(e->param[0]) && verify_expr(e->param[1])
651 && (!e->param[2] || verify_expr(e->param[2]));
652 case e_between:
653 case e_clip:
654 return verify_expr(e->param[0]) &&
655 verify_expr(e->param[1]) &&
656 verify_expr(e->param[2]);
657 default: return verify_expr(e->param[0]) && verify_expr(e->param[1]) && !e->param[2];
658 }
659}
660
661int av_expr_parse(AVExpr **expr, const char *s,
662 const char * const *const_names,
663 const char * const *func1_names, double (* const *funcs1)(void *, double),
664 const char * const *func2_names, double (* const *funcs2)(void *, double, double),
665 int log_offset, void *log_ctx)
666{
667 Parser p = { 0 };
668 AVExpr *e = NULL;
669 char *w = av_malloc(strlen(s) + 1);
670 char *wp = w;
671 const char *s0 = s;
672 int ret = 0;
673
674 if (!w)
675 return AVERROR(ENOMEM);
676
677 while (*s)
678 if (!av_isspace(*s++)) *wp++ = s[-1];
679 *wp++ = 0;
680
681 p.class = &eval_class;
682 p.stack_index=100;
683 p.s= w;
684 p.const_names = const_names;
685 p.funcs1 = funcs1;
686 p.func1_names = func1_names;
687 p.funcs2 = funcs2;
688 p.func2_names = func2_names;
689 p.log_offset = log_offset;
690 p.log_ctx = log_ctx;
691
692 if ((ret = parse_expr(&e, &p)) < 0)
693 goto end;
694 if (*p.s) {
695 av_log(&p, AV_LOG_ERROR, "Invalid chars '%s' at the end of expression '%s'\n", p.s, s0);
696 ret = AVERROR(EINVAL);
697 goto end;
698 }
699 if (!verify_expr(e)) {
700 ret = AVERROR(EINVAL);
701 goto end;
702 }
703 e->var= av_mallocz(sizeof(double) *VARS);
704 if (!e->var) {
705 ret = AVERROR(ENOMEM);
706 goto end;
707 }
708 *expr = e;
709 e = NULL;
710end:
711 av_expr_free(e);
712 av_free(w);
713 return ret;
714}
715
716double av_expr_eval(AVExpr *e, const double *const_values, void *opaque)
717{
718 Parser p = { 0 };
719 p.var= e->var;
720
721 p.const_values = const_values;
722 p.opaque = opaque;
723 return eval_expr(&p, e);
724}
725
726int av_expr_parse_and_eval(double *d, const char *s,
727 const char * const *const_names, const double *const_values,
728 const char * const *func1_names, double (* const *funcs1)(void *, double),
729 const char * const *func2_names, double (* const *funcs2)(void *, double, double),
730 void *opaque, int log_offset, void *log_ctx)
731{
732 AVExpr *e = NULL;
733 int ret = av_expr_parse(&e, s, const_names, func1_names, funcs1, func2_names, funcs2, log_offset, log_ctx);
734
735 if (ret < 0) {
736 *d = NAN;
737 return ret;
738 }
739 *d = av_expr_eval(e, const_values, opaque);
740 av_expr_free(e);
741 return isnan(*d) ? AVERROR(EINVAL) : 0;
742}
743
generated by cgit at 2024-05-17 05:49:01 (GMT)