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85 lines
4.0 KiB
C
85 lines
4.0 KiB
C
/*
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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 AVCODEC_EVAL_H
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#define AVCODEC_EVAL_H
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#if LIBAVCODEC_VERSION_INT < ((52<<16)+(0<<8)+0)
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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(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, 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 its not needed anymore
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* NULL if anything went wrong
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*/
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AVEvalExpr * ff_parse(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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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 /* AVCODEC_EVAL_H */
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