| /* |
| * Copyright (c) 2002-2006 Michael Niedermayer <michaelni@gmx.at> |
| * Copyright (c) 2006 Oded Shimon <ods15@ods15.dyndns.org> |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /** |
| * @file |
| * simple arithmetic expression evaluator. |
| * |
| * see http://joe.hotchkiss.com/programming/eval/eval.html |
| */ |
| |
| #include <float.h> |
| #include "attributes.h" |
| #include "avutil.h" |
| #include "common.h" |
| #include "eval.h" |
| #include "ffmath.h" |
| #include "internal.h" |
| #include "log.h" |
| #include "mathematics.h" |
| #include "time.h" |
| #include "avstring.h" |
| #include "timer.h" |
| #include "reverse.h" |
| |
| typedef struct Parser { |
| const AVClass *class; |
| int stack_index; |
| char *s; |
| const double *const_values; |
| const char * const *const_names; // NULL terminated |
| double (* const *funcs1)(void *, double a); // NULL terminated |
| const char * const *func1_names; // NULL terminated |
| double (* const *funcs2)(void *, double a, double b); // NULL terminated |
| const char * const *func2_names; // NULL terminated |
| void *opaque; |
| int log_offset; |
| void *log_ctx; |
| #define VARS 10 |
| double *var; |
| } Parser; |
| |
| static const AVClass eval_class = { |
| .class_name = "Eval", |
| .item_name = av_default_item_name, |
| .option = NULL, |
| .version = LIBAVUTIL_VERSION_INT, |
| .log_level_offset_offset = offsetof(Parser, log_offset), |
| .parent_log_context_offset = offsetof(Parser, log_ctx), |
| }; |
| |
| static const struct { |
| double bin_val; |
| double dec_val; |
| int8_t exp; |
| } si_prefixes['z' - 'E' + 1] = { |
| ['y'-'E']= { 8.271806125530276749e-25, 1e-24, -24 }, |
| ['z'-'E']= { 8.4703294725430034e-22, 1e-21, -21 }, |
| ['a'-'E']= { 8.6736173798840355e-19, 1e-18, -18 }, |
| ['f'-'E']= { 8.8817841970012523e-16, 1e-15, -15 }, |
| ['p'-'E']= { 9.0949470177292824e-13, 1e-12, -12 }, |
| ['n'-'E']= { 9.3132257461547852e-10, 1e-9, -9 }, |
| ['u'-'E']= { 9.5367431640625e-7, 1e-6, -6 }, |
| ['m'-'E']= { 9.765625e-4, 1e-3, -3 }, |
| ['c'-'E']= { 9.8431332023036951e-3, 1e-2, -2 }, |
| ['d'-'E']= { 9.921256574801246e-2, 1e-1, -1 }, |
| ['h'-'E']= { 1.0159366732596479e2, 1e2, 2 }, |
| ['k'-'E']= { 1.024e3, 1e3, 3 }, |
| ['K'-'E']= { 1.024e3, 1e3, 3 }, |
| ['M'-'E']= { 1.048576e6, 1e6, 6 }, |
| ['G'-'E']= { 1.073741824e9, 1e9, 9 }, |
| ['T'-'E']= { 1.099511627776e12, 1e12, 12 }, |
| ['P'-'E']= { 1.125899906842624e15, 1e15, 15 }, |
| ['E'-'E']= { 1.152921504606847e18, 1e18, 18 }, |
| ['Z'-'E']= { 1.1805916207174113e21, 1e21, 21 }, |
| ['Y'-'E']= { 1.2089258196146292e24, 1e24, 24 }, |
| }; |
| |
| static const struct { |
| const char *name; |
| double value; |
| } constants[] = { |
| { "E", M_E }, |
| { "PI", M_PI }, |
| { "PHI", M_PHI }, |
| { "QP2LAMBDA", FF_QP2LAMBDA }, |
| }; |
| |
| double av_strtod(const char *numstr, char **tail) |
| { |
| double d; |
| char *next; |
| if(numstr[0]=='0' && (numstr[1]|0x20)=='x') { |
| d = strtoul(numstr, &next, 16); |
| } else |
| d = strtod(numstr, &next); |
| /* if parsing succeeded, check for and interpret postfixes */ |
| if (next!=numstr) { |
| if (next[0] == 'd' && next[1] == 'B') { |
| /* treat dB as decibels instead of decibytes */ |
| d = ff_exp10(d / 20); |
| next += 2; |
| } else if (*next >= 'E' && *next <= 'z') { |
| int e= si_prefixes[*next - 'E'].exp; |
| if (e) { |
| if (next[1] == 'i') { |
| d*= si_prefixes[*next - 'E'].bin_val; |
| next+=2; |
| } else { |
| d*= si_prefixes[*next - 'E'].dec_val; |
| next++; |
| } |
| } |
| } |
| |
| if (*next=='B') { |
| d*=8; |
| next++; |
| } |
| } |
| /* if requested, fill in tail with the position after the last parsed |
| character */ |
| if (tail) |
| *tail = next; |
| return d; |
| } |
| |
| #define IS_IDENTIFIER_CHAR(c) ((c) - '0' <= 9U || (c) - 'a' <= 25U || (c) - 'A' <= 25U || (c) == '_') |
| |
| static int strmatch(const char *s, const char *prefix) |
| { |
| int i; |
| for (i=0; prefix[i]; i++) { |
| if (prefix[i] != s[i]) return 0; |
| } |
| /* return 1 only if the s identifier is terminated */ |
| return !IS_IDENTIFIER_CHAR(s[i]); |
| } |
| |
| struct AVExpr { |
| enum { |
| e_value, e_const, e_func0, e_func1, e_func2, |
| e_squish, e_gauss, e_ld, e_isnan, e_isinf, |
| e_mod, e_max, e_min, e_eq, e_gt, e_gte, e_lte, e_lt, |
| e_pow, e_mul, e_div, e_add, |
| e_last, e_st, e_while, e_taylor, e_root, e_floor, e_ceil, e_trunc, e_round, |
| e_sqrt, e_not, e_random, e_hypot, e_gcd, |
| e_if, e_ifnot, e_print, e_bitand, e_bitor, e_between, e_clip, e_atan2, e_lerp, |
| } type; |
| double value; // is sign in other types |
| union { |
| int const_index; |
| double (*func0)(double); |
| double (*func1)(void *, double); |
| double (*func2)(void *, double, double); |
| } a; |
| struct AVExpr *param[3]; |
| double *var; |
| }; |
| |
| static double etime(double v) |
| { |
| return av_gettime() * 0.000001; |
| } |
| |
| static double eval_expr(Parser *p, AVExpr *e) |
| { |
| switch (e->type) { |
| case e_value: return e->value; |
| case e_const: return e->value * p->const_values[e->a.const_index]; |
| case e_func0: return e->value * e->a.func0(eval_expr(p, e->param[0])); |
| case e_func1: return e->value * e->a.func1(p->opaque, eval_expr(p, e->param[0])); |
| case e_func2: return e->value * e->a.func2(p->opaque, eval_expr(p, e->param[0]), eval_expr(p, e->param[1])); |
| case e_squish: return 1/(1+exp(4*eval_expr(p, e->param[0]))); |
| case e_gauss: { double d = eval_expr(p, e->param[0]); return exp(-d*d/2)/sqrt(2*M_PI); } |
| case e_ld: return e->value * p->var[av_clip(eval_expr(p, e->param[0]), 0, VARS-1)]; |
| case e_isnan: return e->value * !!isnan(eval_expr(p, e->param[0])); |
| case e_isinf: return e->value * !!isinf(eval_expr(p, e->param[0])); |
| case e_floor: return e->value * floor(eval_expr(p, e->param[0])); |
| case e_ceil : return e->value * ceil (eval_expr(p, e->param[0])); |
| case e_trunc: return e->value * trunc(eval_expr(p, e->param[0])); |
| case e_round: return e->value * round(eval_expr(p, e->param[0])); |
| case e_sqrt: return e->value * sqrt (eval_expr(p, e->param[0])); |
| case e_not: return e->value * (eval_expr(p, e->param[0]) == 0); |
| case e_if: return e->value * (eval_expr(p, e->param[0]) ? eval_expr(p, e->param[1]) : |
| e->param[2] ? eval_expr(p, e->param[2]) : 0); |
| case e_ifnot: return e->value * (!eval_expr(p, e->param[0]) ? eval_expr(p, e->param[1]) : |
| e->param[2] ? eval_expr(p, e->param[2]) : 0); |
| case e_clip: { |
| double x = eval_expr(p, e->param[0]); |
| double min = eval_expr(p, e->param[1]), max = eval_expr(p, e->param[2]); |
| if (isnan(min) || isnan(max) || isnan(x) || min > max) |
| return NAN; |
| return e->value * av_clipd(eval_expr(p, e->param[0]), min, max); |
| } |
| case e_between: { |
| double d = eval_expr(p, e->param[0]); |
| return e->value * (d >= eval_expr(p, e->param[1]) && |
| d <= eval_expr(p, e->param[2])); |
| } |
| case e_lerp: { |
| double v0 = eval_expr(p, e->param[0]); |
| double v1 = eval_expr(p, e->param[1]); |
| double f = eval_expr(p, e->param[2]); |
| return v0 + (v1 - v0) * f; |
| } |
| case e_print: { |
| double x = eval_expr(p, e->param[0]); |
| int level = e->param[1] ? av_clip(eval_expr(p, e->param[1]), INT_MIN, INT_MAX) : AV_LOG_INFO; |
| av_log(p, level, "%f\n", x); |
| return x; |
| } |
| case e_random:{ |
| int idx= av_clip(eval_expr(p, e->param[0]), 0, VARS-1); |
| uint64_t r= isnan(p->var[idx]) ? 0 : p->var[idx]; |
| r= r*1664525+1013904223; |
| p->var[idx]= r; |
| return e->value * (r * (1.0/UINT64_MAX)); |
| } |
| case e_while: { |
| double d = NAN; |
| while (eval_expr(p, e->param[0])) |
| d=eval_expr(p, e->param[1]); |
| return d; |
| } |
| case e_taylor: { |
| double t = 1, d = 0, v; |
| double x = eval_expr(p, e->param[1]); |
| int id = e->param[2] ? av_clip(eval_expr(p, e->param[2]), 0, VARS-1) : 0; |
| int i; |
| double var0 = p->var[id]; |
| for(i=0; i<1000; i++) { |
| double ld = d; |
| p->var[id] = i; |
| v = eval_expr(p, e->param[0]); |
| d += t*v; |
| if(ld==d && v) |
| break; |
| t *= x / (i+1); |
| } |
| p->var[id] = var0; |
| return d; |
| } |
| case e_root: { |
| int i, j; |
| double low = -1, high = -1, v, low_v = -DBL_MAX, high_v = DBL_MAX; |
| double var0 = p->var[0]; |
| double x_max = eval_expr(p, e->param[1]); |
| for(i=-1; i<1024; i++) { |
| if(i<255) { |
| p->var[0] = ff_reverse[i&255]*x_max/255; |
| } else { |
| p->var[0] = x_max*pow(0.9, i-255); |
| if (i&1) p->var[0] *= -1; |
| if (i&2) p->var[0] += low; |
| else p->var[0] += high; |
| } |
| v = eval_expr(p, e->param[0]); |
| if (v<=0 && v>low_v) { |
| low = p->var[0]; |
| low_v = v; |
| } |
| if (v>=0 && v<high_v) { |
| high = p->var[0]; |
| high_v = v; |
| } |
| if (low>=0 && high>=0){ |
| for (j=0; j<1000; j++) { |
| p->var[0] = (low+high)*0.5; |
| if (low == p->var[0] || high == p->var[0]) |
| break; |
| v = eval_expr(p, e->param[0]); |
| if (v<=0) low = p->var[0]; |
| if (v>=0) high= p->var[0]; |
| if (isnan(v)) { |
| low = high = v; |
| break; |
| } |
| } |
| break; |
| } |
| } |
| p->var[0] = var0; |
| return -low_v<high_v ? low : high; |
| } |
| default: { |
| double d = eval_expr(p, e->param[0]); |
| double d2 = eval_expr(p, e->param[1]); |
| switch (e->type) { |
| case e_mod: return e->value * (d - floor((!CONFIG_FTRAPV || d2) ? d / d2 : d * INFINITY) * d2); |
| case e_gcd: return e->value * av_gcd(d,d2); |
| case e_max: return e->value * (d > d2 ? d : d2); |
| case e_min: return e->value * (d < d2 ? d : d2); |
| case e_eq: return e->value * (d == d2 ? 1.0 : 0.0); |
| case e_gt: return e->value * (d > d2 ? 1.0 : 0.0); |
| case e_gte: return e->value * (d >= d2 ? 1.0 : 0.0); |
| case e_lt: return e->value * (d < d2 ? 1.0 : 0.0); |
| case e_lte: return e->value * (d <= d2 ? 1.0 : 0.0); |
| case e_pow: return e->value * pow(d, d2); |
| case e_mul: return e->value * (d * d2); |
| case e_div: return e->value * ((!CONFIG_FTRAPV || d2 ) ? (d / d2) : d * INFINITY); |
| case e_add: return e->value * (d + d2); |
| case e_last:return e->value * d2; |
| case e_st : return e->value * (p->var[av_clip(d, 0, VARS-1)]= d2); |
| case e_hypot:return e->value * hypot(d, d2); |
| case e_atan2:return e->value * atan2(d, d2); |
| case e_bitand: return isnan(d) || isnan(d2) ? NAN : e->value * ((long int)d & (long int)d2); |
| case e_bitor: return isnan(d) || isnan(d2) ? NAN : e->value * ((long int)d | (long int)d2); |
| } |
| } |
| } |
| return NAN; |
| } |
| |
| static int parse_expr(AVExpr **e, Parser *p); |
| |
| void av_expr_free(AVExpr *e) |
| { |
| if (!e) return; |
| av_expr_free(e->param[0]); |
| av_expr_free(e->param[1]); |
| av_expr_free(e->param[2]); |
| av_freep(&e->var); |
| av_freep(&e); |
| } |
| |
| static int parse_primary(AVExpr **e, Parser *p) |
| { |
| AVExpr *d = av_mallocz(sizeof(AVExpr)); |
| char *next = p->s, *s0 = p->s; |
| int ret, i; |
| |
| if (!d) |
| return AVERROR(ENOMEM); |
| |
| /* number */ |
| d->value = av_strtod(p->s, &next); |
| if (next != p->s) { |
| d->type = e_value; |
| p->s= next; |
| *e = d; |
| return 0; |
| } |
| d->value = 1; |
| |
| /* named constants */ |
| for (i=0; p->const_names && p->const_names[i]; i++) { |
| if (strmatch(p->s, p->const_names[i])) { |
| p->s+= strlen(p->const_names[i]); |
| d->type = e_const; |
| d->a.const_index = i; |
| *e = d; |
| return 0; |
| } |
| } |
| for (i = 0; i < FF_ARRAY_ELEMS(constants); i++) { |
| if (strmatch(p->s, constants[i].name)) { |
| p->s += strlen(constants[i].name); |
| d->type = e_value; |
| d->value = constants[i].value; |
| *e = d; |
| return 0; |
| } |
| } |
| |
| p->s= strchr(p->s, '('); |
| if (!p->s) { |
| av_log(p, AV_LOG_ERROR, "Undefined constant or missing '(' in '%s'\n", s0); |
| p->s= next; |
| av_expr_free(d); |
| return AVERROR(EINVAL); |
| } |
| p->s++; // "(" |
| if (*next == '(') { // special case do-nothing |
| av_freep(&d); |
| if ((ret = parse_expr(&d, p)) < 0) |
| return ret; |
| if (p->s[0] != ')') { |
| av_log(p, AV_LOG_ERROR, "Missing ')' in '%s'\n", s0); |
| av_expr_free(d); |
| return AVERROR(EINVAL); |
| } |
| p->s++; // ")" |
| *e = d; |
| return 0; |
| } |
| if ((ret = parse_expr(&(d->param[0]), p)) < 0) { |
| av_expr_free(d); |
| return ret; |
| } |
| if (p->s[0]== ',') { |
| p->s++; // "," |
| parse_expr(&d->param[1], p); |
| } |
| if (p->s[0]== ',') { |
| p->s++; // "," |
| parse_expr(&d->param[2], p); |
| } |
| if (p->s[0] != ')') { |
| av_log(p, AV_LOG_ERROR, "Missing ')' or too many args in '%s'\n", s0); |
| av_expr_free(d); |
| return AVERROR(EINVAL); |
| } |
| p->s++; // ")" |
| |
| d->type = e_func0; |
| if (strmatch(next, "sinh" )) d->a.func0 = sinh; |
| else if (strmatch(next, "cosh" )) d->a.func0 = cosh; |
| else if (strmatch(next, "tanh" )) d->a.func0 = tanh; |
| else if (strmatch(next, "sin" )) d->a.func0 = sin; |
| else if (strmatch(next, "cos" )) d->a.func0 = cos; |
| else if (strmatch(next, "tan" )) d->a.func0 = tan; |
| else if (strmatch(next, "atan" )) d->a.func0 = atan; |
| else if (strmatch(next, "asin" )) d->a.func0 = asin; |
| else if (strmatch(next, "acos" )) d->a.func0 = acos; |
| else if (strmatch(next, "exp" )) d->a.func0 = exp; |
| else if (strmatch(next, "log" )) d->a.func0 = log; |
| else if (strmatch(next, "abs" )) d->a.func0 = fabs; |
| else if (strmatch(next, "time" )) d->a.func0 = etime; |
| else if (strmatch(next, "squish")) d->type = e_squish; |
| else if (strmatch(next, "gauss" )) d->type = e_gauss; |
| else if (strmatch(next, "mod" )) d->type = e_mod; |
| else if (strmatch(next, "max" )) d->type = e_max; |
| else if (strmatch(next, "min" )) d->type = e_min; |
| else if (strmatch(next, "eq" )) d->type = e_eq; |
| else if (strmatch(next, "gte" )) d->type = e_gte; |
| else if (strmatch(next, "gt" )) d->type = e_gt; |
| else if (strmatch(next, "lte" )) d->type = e_lte; |
| else if (strmatch(next, "lt" )) d->type = e_lt; |
| else if (strmatch(next, "ld" )) d->type = e_ld; |
| else if (strmatch(next, "isnan" )) d->type = e_isnan; |
| else if (strmatch(next, "isinf" )) d->type = e_isinf; |
| else if (strmatch(next, "st" )) d->type = e_st; |
| else if (strmatch(next, "while" )) d->type = e_while; |
| else if (strmatch(next, "taylor")) d->type = e_taylor; |
| else if (strmatch(next, "root" )) d->type = e_root; |
| else if (strmatch(next, "floor" )) d->type = e_floor; |
| else if (strmatch(next, "ceil" )) d->type = e_ceil; |
| else if (strmatch(next, "trunc" )) d->type = e_trunc; |
| else if (strmatch(next, "round" )) d->type = e_round; |
| else if (strmatch(next, "sqrt" )) d->type = e_sqrt; |
| else if (strmatch(next, "not" )) d->type = e_not; |
| else if (strmatch(next, "pow" )) d->type = e_pow; |
| else if (strmatch(next, "print" )) d->type = e_print; |
| else if (strmatch(next, "random")) d->type = e_random; |
| else if (strmatch(next, "hypot" )) d->type = e_hypot; |
| else if (strmatch(next, "gcd" )) d->type = e_gcd; |
| else if (strmatch(next, "if" )) d->type = e_if; |
| else if (strmatch(next, "ifnot" )) d->type = e_ifnot; |
| else if (strmatch(next, "bitand")) d->type = e_bitand; |
| else if (strmatch(next, "bitor" )) d->type = e_bitor; |
| else if (strmatch(next, "between"))d->type = e_between; |
| else if (strmatch(next, "clip" )) d->type = e_clip; |
| else if (strmatch(next, "atan2" )) d->type = e_atan2; |
| else if (strmatch(next, "lerp" )) d->type = e_lerp; |
| else { |
| for (i=0; p->func1_names && p->func1_names[i]; i++) { |
| if (strmatch(next, p->func1_names[i])) { |
| d->a.func1 = p->funcs1[i]; |
| d->type = e_func1; |
| *e = d; |
| return 0; |
| } |
| } |
| |
| for (i=0; p->func2_names && p->func2_names[i]; i++) { |
| if (strmatch(next, p->func2_names[i])) { |
| d->a.func2 = p->funcs2[i]; |
| d->type = e_func2; |
| *e = d; |
| return 0; |
| } |
| } |
| |
| av_log(p, AV_LOG_ERROR, "Unknown function in '%s'\n", s0); |
| av_expr_free(d); |
| return AVERROR(EINVAL); |
| } |
| |
| *e = d; |
| return 0; |
| } |
| |
| static AVExpr *make_eval_expr(int type, int value, AVExpr *p0, AVExpr *p1) |
| { |
| AVExpr *e = av_mallocz(sizeof(AVExpr)); |
| if (!e) |
| return NULL; |
| e->type =type ; |
| e->value =value ; |
| e->param[0] =p0 ; |
| e->param[1] =p1 ; |
| return e; |
| } |
| |
| static int parse_pow(AVExpr **e, Parser *p, int *sign) |
| { |
| *sign= (*p->s == '+') - (*p->s == '-'); |
| p->s += *sign&1; |
| return parse_primary(e, p); |
| } |
| |
| static int parse_dB(AVExpr **e, Parser *p, int *sign) |
| { |
| /* do not filter out the negative sign when parsing a dB value. |
| for example, -3dB is not the same as -(3dB) */ |
| if (*p->s == '-') { |
| char *next; |
| double av_unused ignored = strtod(p->s, &next); |
| if (next != p->s && next[0] == 'd' && next[1] == 'B') { |
| *sign = 0; |
| return parse_primary(e, p); |
| } |
| } |
| return parse_pow(e, p, sign); |
| } |
| |
| static int parse_factor(AVExpr **e, Parser *p) |
| { |
| int sign, sign2, ret; |
| AVExpr *e0, *e1, *e2; |
| if ((ret = parse_dB(&e0, p, &sign)) < 0) |
| return ret; |
| while(p->s[0]=='^'){ |
| e1 = e0; |
| p->s++; |
| if ((ret = parse_dB(&e2, p, &sign2)) < 0) { |
| av_expr_free(e1); |
| return ret; |
| } |
| e0 = make_eval_expr(e_pow, 1, e1, e2); |
| if (!e0) { |
| av_expr_free(e1); |
| av_expr_free(e2); |
| return AVERROR(ENOMEM); |
| } |
| if (e0->param[1]) e0->param[1]->value *= (sign2|1); |
| } |
| if (e0) e0->value *= (sign|1); |
| |
| *e = e0; |
| return 0; |
| } |
| |
| static int parse_term(AVExpr **e, Parser *p) |
| { |
| int ret; |
| AVExpr *e0, *e1, *e2; |
| if ((ret = parse_factor(&e0, p)) < 0) |
| return ret; |
| while (p->s[0]=='*' || p->s[0]=='/') { |
| int c= *p->s++; |
| e1 = e0; |
| if ((ret = parse_factor(&e2, p)) < 0) { |
| av_expr_free(e1); |
| return ret; |
| } |
| e0 = make_eval_expr(c == '*' ? e_mul : e_div, 1, e1, e2); |
| if (!e0) { |
| av_expr_free(e1); |
| av_expr_free(e2); |
| return AVERROR(ENOMEM); |
| } |
| } |
| *e = e0; |
| return 0; |
| } |
| |
| static int parse_subexpr(AVExpr **e, Parser *p) |
| { |
| int ret; |
| AVExpr *e0, *e1, *e2; |
| if ((ret = parse_term(&e0, p)) < 0) |
| return ret; |
| while (*p->s == '+' || *p->s == '-') { |
| e1 = e0; |
| if ((ret = parse_term(&e2, p)) < 0) { |
| av_expr_free(e1); |
| return ret; |
| } |
| e0 = make_eval_expr(e_add, 1, e1, e2); |
| if (!e0) { |
| av_expr_free(e1); |
| av_expr_free(e2); |
| return AVERROR(ENOMEM); |
| } |
| }; |
| |
| *e = e0; |
| return 0; |
| } |
| |
| static int parse_expr(AVExpr **e, Parser *p) |
| { |
| int ret; |
| AVExpr *e0, *e1, *e2; |
| if (p->stack_index <= 0) //protect against stack overflows |
| return AVERROR(EINVAL); |
| p->stack_index--; |
| |
| if ((ret = parse_subexpr(&e0, p)) < 0) |
| return ret; |
| while (*p->s == ';') { |
| p->s++; |
| e1 = e0; |
| if ((ret = parse_subexpr(&e2, p)) < 0) { |
| av_expr_free(e1); |
| return ret; |
| } |
| e0 = make_eval_expr(e_last, 1, e1, e2); |
| if (!e0) { |
| av_expr_free(e1); |
| av_expr_free(e2); |
| return AVERROR(ENOMEM); |
| } |
| }; |
| |
| p->stack_index++; |
| *e = e0; |
| return 0; |
| } |
| |
| static int verify_expr(AVExpr *e) |
| { |
| if (!e) return 0; |
| switch (e->type) { |
| case e_value: |
| case e_const: return 1; |
| case e_func0: |
| case e_func1: |
| case e_squish: |
| case e_ld: |
| case e_gauss: |
| case e_isnan: |
| case e_isinf: |
| case e_floor: |
| case e_ceil: |
| case e_trunc: |
| case e_round: |
| case e_sqrt: |
| case e_not: |
| case e_random: |
| return verify_expr(e->param[0]) && !e->param[1]; |
| case e_print: |
| return verify_expr(e->param[0]) |
| && (!e->param[1] || verify_expr(e->param[1])); |
| case e_if: |
| case e_ifnot: |
| case e_taylor: |
| return verify_expr(e->param[0]) && verify_expr(e->param[1]) |
| && (!e->param[2] || verify_expr(e->param[2])); |
| case e_between: |
| case e_clip: |
| case e_lerp: |
| return verify_expr(e->param[0]) && |
| verify_expr(e->param[1]) && |
| verify_expr(e->param[2]); |
| default: return verify_expr(e->param[0]) && verify_expr(e->param[1]) && !e->param[2]; |
| } |
| } |
| |
| int av_expr_parse(AVExpr **expr, const char *s, |
| const char * const *const_names, |
| const char * const *func1_names, double (* const *funcs1)(void *, double), |
| const char * const *func2_names, double (* const *funcs2)(void *, double, double), |
| int log_offset, void *log_ctx) |
| { |
| Parser p = { 0 }; |
| AVExpr *e = NULL; |
| char *w = av_malloc(strlen(s) + 1); |
| char *wp = w; |
| const char *s0 = s; |
| int ret = 0; |
| |
| if (!w) |
| return AVERROR(ENOMEM); |
| |
| while (*s) |
| if (!av_isspace(*s++)) *wp++ = s[-1]; |
| *wp++ = 0; |
| |
| p.class = &eval_class; |
| p.stack_index=100; |
| p.s= w; |
| p.const_names = const_names; |
| p.funcs1 = funcs1; |
| p.func1_names = func1_names; |
| p.funcs2 = funcs2; |
| p.func2_names = func2_names; |
| p.log_offset = log_offset; |
| p.log_ctx = log_ctx; |
| |
| if ((ret = parse_expr(&e, &p)) < 0) |
| goto end; |
| if (*p.s) { |
| av_log(&p, AV_LOG_ERROR, "Invalid chars '%s' at the end of expression '%s'\n", p.s, s0); |
| ret = AVERROR(EINVAL); |
| goto end; |
| } |
| if (!verify_expr(e)) { |
| ret = AVERROR(EINVAL); |
| goto end; |
| } |
| e->var= av_mallocz(sizeof(double) *VARS); |
| if (!e->var) { |
| ret = AVERROR(ENOMEM); |
| goto end; |
| } |
| *expr = e; |
| e = NULL; |
| end: |
| av_expr_free(e); |
| av_free(w); |
| return ret; |
| } |
| |
| double av_expr_eval(AVExpr *e, const double *const_values, void *opaque) |
| { |
| Parser p = { 0 }; |
| p.var= e->var; |
| |
| p.const_values = const_values; |
| p.opaque = opaque; |
| return eval_expr(&p, e); |
| } |
| |
| int av_expr_parse_and_eval(double *d, const char *s, |
| const char * const *const_names, const double *const_values, |
| const char * const *func1_names, double (* const *funcs1)(void *, double), |
| const char * const *func2_names, double (* const *funcs2)(void *, double, double), |
| void *opaque, int log_offset, void *log_ctx) |
| { |
| AVExpr *e = NULL; |
| int ret = av_expr_parse(&e, s, const_names, func1_names, funcs1, func2_names, funcs2, log_offset, log_ctx); |
| |
| if (ret < 0) { |
| *d = NAN; |
| return ret; |
| } |
| *d = av_expr_eval(e, const_values, opaque); |
| av_expr_free(e); |
| return isnan(*d) ? AVERROR(EINVAL) : 0; |
| } |
