*
* Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
*
- * This library is free software; you can redistribute it and/or
+ * 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 of the License, or (at your option) any later version.
+ * version 2.1 of the License, or (at your option) any later version.
*
- * This library is distributed in the hope that it will be useful,
+ * 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 this library; if not, write to the Free Software
+ * 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
+ * @file libavcodec/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,
+/**
+ * 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), char **func2_name,
- void *opaque);
-#endif
-double ff_eval2(char *s, double *const_value, const char **const_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), char **func2_name,
- void *opaque, char **error);
+ 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);
+
+/**
+ * Parses the string in numstr and returns its value as a double. If
+ * the string is empty, contains only whitespaces, or does not contain
+ * an initial substring that has the expected syntax for a
+ * floating-point number, no conversion is performed. In this case,
+ * returns a value of zero and the value returned in tail is the value
+ * of numstr.
+ *
+ * @param numstr a string representing a number, may contain one of
+ * the International System number postfixes, for example 'K', 'M',
+ * 'G'. If 'i' is appended after the postfix, powers of 2 are used
+ * instead of powers of 10. The 'B' postfix multiplies the value for
+ * 8, and can be appended after another postfix or used alone. This
+ * allows using for example 'KB', 'MiB', 'G' and 'B' as postfix.
+ * @param tail if non-NULL puts here the pointer to the char next
+ * after the last parsed character
+ */
+double av_strtod(const char *numstr, char **tail);
#endif /* AVCODEC_EVAL_H */
projects / ffmpeg / blobdiff