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87 lines
4.0 KiB
87 lines
4.0 KiB
/* |
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* simple arithmetic expression evaluator |
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* |
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* Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at> |
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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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* @file eval.h |
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* eval header. |
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*/ |
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#ifndef FFMPEG_EVAL_H |
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#define FFMPEG_EVAL_H |
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#if LIBAVCODEC_VERSION_INT < ((52<<16)+(0<<8)+0) |
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/** |
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* @deprecated Use ff_eval2 instead |
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*/ |
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double ff_eval(char *s, double *const_value, const char **const_name, |
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double (**func1)(void *, double), const char **func1_name, |
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double (**func2)(void *, double, double), char **func2_name, |
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void *opaque); |
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#endif |
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/** |
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* Parses and evaluates an expression. |
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* Note, this is significantly slower than ff_parse_eval() |
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* @param s expression as a zero terminated string for example "1+2^3+5*5+sin(2/3)" |
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* @param func1 NULL terminated array of function pointers for functions which take 1 argument |
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* @param func2 NULL terminated array of function pointers for functions which take 2 arguments |
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* @param const_name NULL terminated array of zero terminated strings of constant identifers for example {"PI", "E", 0} |
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* @param func1_name NULL terminated array of zero terminated strings of func1 identifers |
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* @param func2_name NULL terminated array of zero terminated strings of func2 identifers |
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* @param error pointer to a char* which is set to an error message if something goes wrong |
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* @param const_value a zero terminated array of values for the identifers from const_name |
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* @param opaque a pointer which will be passed to all functions from func1 and func2 |
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* @return the value of the expression |
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*/ |
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double ff_eval2(const char *s, double *const_value, const char **const_name, |
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double (**func1)(void *, double), const char **func1_name, |
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double (**func2)(void *, double, double), char **func2_name, |
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void *opaque, const char **error); |
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typedef struct ff_expr_s AVEvalExpr; |
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/** |
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* Parses a expression. |
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* @param s expression as a zero terminated string for example "1+2^3+5*5+sin(2/3)" |
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* @param func1 NULL terminated array of function pointers for functions which take 1 argument |
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* @param func2 NULL terminated array of function pointers for functions which take 2 arguments |
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* @param const_name NULL terminated array of zero terminated strings of constant identifers for example {"PI", "E", 0} |
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* @param func1_name NULL terminated array of zero terminated strings of func1 identifers |
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* @param func2_name NULL terminated array of zero terminated strings of func2 identifers |
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* @param error pointer to a char* which is set to an error message if something goes wrong |
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* @return AVEvalExpr which must be freed with ff_eval_free by the user when it is not needed anymore |
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* NULL if anything went wrong |
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*/ |
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AVEvalExpr * ff_parse(const char *s, const char **const_name, |
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double (**func1)(void *, double), const char **func1_name, |
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double (**func2)(void *, double, double), char **func2_name, |
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const char **error); |
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/** |
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* Evaluates a previously parsed expression. |
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* @param const_value a zero terminated array of values for the identifers from ff_parse const_name |
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* @param opaque a pointer which will be passed to all functions from func1 and func2 |
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* @return the value of the expression |
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*/ |
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double ff_parse_eval(AVEvalExpr * e, double *const_value, void *opaque); |
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void ff_eval_free(AVEvalExpr * e); |
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#endif /* FFMPEG_EVAL_H */
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