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Diffstat (limited to 'src/libffmpeg/libavcodec/eval.h')
-rw-r--r-- | src/libffmpeg/libavcodec/eval.h | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/src/libffmpeg/libavcodec/eval.h b/src/libffmpeg/libavcodec/eval.h new file mode 100644 index 000000000..b52199cf4 --- /dev/null +++ b/src/libffmpeg/libavcodec/eval.h @@ -0,0 +1,84 @@ +/* + * 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 + +#if LIBAVCODEC_VERSION_INT < ((52<<16)+(0<<8)+0) +double ff_eval(char *s, double *const_value, const char **const_name, + double (**func1)(void *, double), const char **func1_name, + double (**func2)(void *, double, double), char **func2_name, + void *opaque); +#endif + +/** + * 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(char *s, double *const_value, const char **const_name, + double (**func1)(void *, double), const char **func1_name, + double (**func2)(void *, double, double), char **func2_name, + void *opaque, 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 its not needed anymore + * NULL if anything went wrong + */ +AVEvalExpr * ff_parse(char *s, const char **const_name, + double (**func1)(void *, double), const char **func1_name, + double (**func2)(void *, double, double), char **func2_name, + 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, double *const_value, void *opaque); +void ff_eval_free(AVEvalExpr * e); + +#endif /* AVCODEC_EVAL_H */ |