b52199cf4c3e3ae2804b1ac3b96709ba3a5d6faa
[libav.git] / libavcodec / eval.h
1 /*
2 * simple arithmetic expression evaluator
3 *
4 * Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 /**
24 * @file eval.h
25 * eval header.
26 */
27
28 #ifndef AVCODEC_EVAL_H
29 #define AVCODEC_EVAL_H
30
31 #if LIBAVCODEC_VERSION_INT < ((52<<16)+(0<<8)+0)
32 double ff_eval(char *s, double *const_value, const char **const_name,
33 double (**func1)(void *, double), const char **func1_name,
34 double (**func2)(void *, double, double), char **func2_name,
35 void *opaque);
36 #endif
37
38 /**
39 * Parses and evaluates an expression.
40 * Note, this is significantly slower than ff_parse_eval()
41 * @param s expression as a zero terminated string for example "1+2^3+5*5+sin(2/3)"
42 * @param func1 NULL terminated array of function pointers for functions which take 1 argument
43 * @param func2 NULL terminated array of function pointers for functions which take 2 arguments
44 * @param const_name NULL terminated array of zero terminated strings of constant identifers for example {"PI", "E", 0}
45 * @param func1_name NULL terminated array of zero terminated strings of func1 identifers
46 * @param func2_name NULL terminated array of zero terminated strings of func2 identifers
47 * @param error pointer to a char* which is set to an error message if something goes wrong
48 * @param const_value a zero terminated array of values for the identifers from const_name
49 * @param opaque a pointer which will be passed to all functions from func1 and func2
50 * @return the value of the expression
51 */
52 double ff_eval2(char *s, double *const_value, const char **const_name,
53 double (**func1)(void *, double), const char **func1_name,
54 double (**func2)(void *, double, double), char **func2_name,
55 void *opaque, char **error);
56
57 typedef struct ff_expr_s AVEvalExpr;
58
59 /**
60 * Parses a expression.
61 * @param s expression as a zero terminated string for example "1+2^3+5*5+sin(2/3)"
62 * @param func1 NULL terminated array of function pointers for functions which take 1 argument
63 * @param func2 NULL terminated array of function pointers for functions which take 2 arguments
64 * @param const_name NULL terminated array of zero terminated strings of constant identifers for example {"PI", "E", 0}
65 * @param func1_name NULL terminated array of zero terminated strings of func1 identifers
66 * @param func2_name NULL terminated array of zero terminated strings of func2 identifers
67 * @param error pointer to a char* which is set to an error message if something goes wrong
68 * @return AVEvalExpr which must be freed with ff_eval_free by the user when its not needed anymore
69 * NULL if anything went wrong
70 */
71 AVEvalExpr * ff_parse(char *s, const char **const_name,
72 double (**func1)(void *, double), const char **func1_name,
73 double (**func2)(void *, double, double), char **func2_name,
74 char **error);
75 /**
76 * Evaluates a previously parsed expression.
77 * @param const_value a zero terminated array of values for the identifers from ff_parse const_name
78 * @param opaque a pointer which will be passed to all functions from func1 and func2
79 * @return the value of the expression
80 */
81 double ff_parse_eval(AVEvalExpr * e, double *const_value, void *opaque);
82 void ff_eval_free(AVEvalExpr * e);
83
84 #endif /* AVCODEC_EVAL_H */