eval.h
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上传日期:2022-07-11
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- /*
- * simple arithmetic expression evaluator
- *
- * Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
- *
- * 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 eval.h
- * eval header.
- */
- #ifndef AVCODEC_EVAL_H
- #define AVCODEC_EVAL_H
- /**
- * Parses and evaluates an expression.
- * Note, this is significantly slower than ff_parse_eval()
- * @param s expression as a zero terminated string for example "1+2^3+5*5+sin(2/3)"
- * @param func1 NULL terminated array of function pointers for functions which take 1 argument
- * @param func2 NULL terminated array of function pointers for functions which take 2 arguments
- * @param const_name NULL terminated array of zero terminated strings of constant identifers for example {"PI", "E", 0}
- * @param func1_name NULL terminated array of zero terminated strings of func1 identifers
- * @param func2_name NULL terminated array of zero terminated strings of func2 identifers
- * @param error pointer to a char* which is set to an error message if something goes wrong
- * @param const_value a zero terminated array of values for the identifers from const_name
- * @param opaque a pointer which will be passed to all functions from func1 and func2
- * @return the value of the expression
- */
- double ff_eval2(const char *s, const double *const_value, const char * const *const_name,
- double (**func1)(void *, double), const char **func1_name,
- double (**func2)(void *, double, double), const char **func2_name,
- void *opaque, const char **error);
- typedef struct ff_expr_s AVEvalExpr;
- /**
- * Parses a expression.
- * @param s expression as a zero terminated string for example "1+2^3+5*5+sin(2/3)"
- * @param func1 NULL terminated array of function pointers for functions which take 1 argument
- * @param func2 NULL terminated array of function pointers for functions which take 2 arguments
- * @param const_name NULL terminated array of zero terminated strings of constant identifers for example {"PI", "E", 0}
- * @param func1_name NULL terminated array of zero terminated strings of func1 identifers
- * @param func2_name NULL terminated array of zero terminated strings of func2 identifers
- * @param error pointer to a char* which is set to an error message if something goes wrong
- * @return AVEvalExpr which must be freed with ff_eval_free by the user when it is not needed anymore
- * NULL if anything went wrong
- */
- AVEvalExpr * ff_parse(const char *s, const char * const *const_name,
- double (**func1)(void *, double), const char **func1_name,
- double (**func2)(void *, double, double), const char **func2_name,
- const char **error);
- /**
- * Evaluates a previously parsed expression.
- * @param const_value a zero terminated array of values for the identifers from ff_parse const_name
- * @param opaque a pointer which will be passed to all functions from func1 and func2
- * @return the value of the expression
- */
- double ff_parse_eval(AVEvalExpr * e, const double *const_value, void *opaque);
- void ff_eval_free(AVEvalExpr * e);
- #endif /* AVCODEC_EVAL_H */