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