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parseutils.h
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #ifndef AVUTIL_PARSEUTILS_H
20 #define AVUTIL_PARSEUTILS_H
21 
22 #include <time.h>
23 
24 #include "rational.h"
25 
26 /**
27  * @file
28  * misc parsing utilities
29  */
30 
31 /**
32  * Parse str and store the parsed ratio in q.
33  *
34  * Note that a ratio with infinite (1/0) or negative value is
35  * considered valid, so you should check on the returned value if you
36  * want to exclude those values.
37  *
38  * The undefined value can be expressed using the "0:0" string.
39  *
40  * @param[in,out] q pointer to the AVRational which will contain the ratio
41  * @param[in] str the string to parse: it has to be a string in the format
42  * num:den, a float number or an expression
43  * @param[in] max the maximum allowed numerator and denominator
44  * @param[in] log_offset log level offset which is applied to the log
45  * level of log_ctx
46  * @param[in] log_ctx parent logging context
47  * @return >= 0 on success, a negative error code otherwise
48  */
49 int av_parse_ratio(AVRational *q, const char *str, int max,
50  int log_offset, void *log_ctx);
51 
52 #define av_parse_ratio_quiet(rate, str, max) \
53  av_parse_ratio(rate, str, max, AV_LOG_MAX_OFFSET, NULL)
54 
55 /**
56  * Parse str and put in width_ptr and height_ptr the detected values.
57  *
58  * @param[in,out] width_ptr pointer to the variable which will contain the detected
59  * width value
60  * @param[in,out] height_ptr pointer to the variable which will contain the detected
61  * height value
62  * @param[in] str the string to parse: it has to be a string in the format
63  * width x height or a valid video size abbreviation.
64  * @return >= 0 on success, a negative error code otherwise
65  */
66 int av_parse_video_size(int *width_ptr, int *height_ptr, const char *str);
67 
68 /**
69  * Parse str and store the detected values in *rate.
70  *
71  * @param[in,out] rate pointer to the AVRational which will contain the detected
72  * frame rate
73  * @param[in] str the string to parse: it has to be a string in the format
74  * rate_num / rate_den, a float number or a valid video rate abbreviation
75  * @return >= 0 on success, a negative error code otherwise
76  */
77 int av_parse_video_rate(AVRational *rate, const char *str);
78 
79 /**
80  * Put the RGBA values that correspond to color_string in rgba_color.
81  *
82  * @param color_string a string specifying a color. It can be the name of
83  * a color (case insensitive match) or a [0x|#]RRGGBB[AA] sequence,
84  * possibly followed by "@" and a string representing the alpha
85  * component.
86  * The alpha component may be a string composed by "0x" followed by an
87  * hexadecimal number or a decimal number between 0.0 and 1.0, which
88  * represents the opacity value (0x00/0.0 means completely transparent,
89  * 0xff/1.0 completely opaque).
90  * If the alpha component is not specified then 0xff is assumed.
91  * The string "random" will result in a random color.
92  * @param slen length of the initial part of color_string containing the
93  * color. It can be set to -1 if color_string is a null terminated string
94  * containing nothing else than the color.
95  * @return >= 0 in case of success, a negative value in case of
96  * failure (for example if color_string cannot be parsed).
97  */
98 int av_parse_color(uint8_t *rgba_color, const char *color_string, int slen,
99  void *log_ctx);
100 
101 /**
102  * Get the name of a color from the internal table of hard-coded named
103  * colors.
104  *
105  * This function is meant to enumerate the color names recognized by
106  * av_parse_color().
107  *
108  * @param color_idx index of the requested color, starting from 0
109  * @param rgbp if not NULL, will point to a 3-elements array with the color value in RGB
110  * @return the color name string or NULL if color_idx is not in the array
111  */
112 const char *av_get_known_color_name(int color_idx, const uint8_t **rgb);
113 
114 /**
115  * Parse timestr and return in *time a corresponding number of
116  * microseconds.
117  *
118  * @param timeval puts here the number of microseconds corresponding
119  * to the string in timestr. If the string represents a duration, it
120  * is the number of microseconds contained in the time interval. If
121  * the string is a date, is the number of microseconds since 1st of
122  * January, 1970 up to the time of the parsed date. If timestr cannot
123  * be successfully parsed, set *time to INT64_MIN.
124 
125  * @param timestr a string representing a date or a duration.
126  * - If a date the syntax is:
127  * @code
128  * [{YYYY-MM-DD|YYYYMMDD}[T|t| ]]{{HH:MM:SS[.m...]]]}|{HHMMSS[.m...]]]}}[Z]
129  * now
130  * @endcode
131  * If the value is "now" it takes the current time.
132  * Time is local time unless Z is appended, in which case it is
133  * interpreted as UTC.
134  * If the year-month-day part is not specified it takes the current
135  * year-month-day.
136  * - If a duration the syntax is:
137  * @code
138  * [-][HH:]MM:SS[.m...]
139  * [-]S+[.m...]
140  * @endcode
141  * @param duration flag which tells how to interpret timestr, if not
142  * zero timestr is interpreted as a duration, otherwise as a date
143  * @return >= 0 in case of success, a negative value corresponding to an
144  * AVERROR code otherwise
145  */
146 int av_parse_time(int64_t *timeval, const char *timestr, int duration);
147 
148 /**
149  * Attempt to find a specific tag in a URL.
150  *
151  * syntax: '?tag1=val1&tag2=val2...'. Little URL decoding is done.
152  * Return 1 if found.
153  */
154 int av_find_info_tag(char *arg, int arg_size, const char *tag1, const char *info);
155 
156 /**
157  * Simplified version of strptime
158  *
159  * Parse the input string p according to the format string fmt and
160  * store its results in the structure dt.
161  * This implementation supports only a subset of the formats supported
162  * by the standard strptime().
163  *
164  * The supported input field descriptors are listed below.
165  * - %H: the hour as a decimal number, using a 24-hour clock, in the
166  * range '00' through '23'
167  * - %J: hours as a decimal number, in the range '0' through INT_MAX
168  * - %M: the minute as a decimal number, using a 24-hour clock, in the
169  * range '00' through '59'
170  * - %S: the second as a decimal number, using a 24-hour clock, in the
171  * range '00' through '59'
172  * - %Y: the year as a decimal number, using the Gregorian calendar
173  * - %m: the month as a decimal number, in the range '1' through '12'
174  * - %d: the day of the month as a decimal number, in the range '1'
175  * through '31'
176  * - %T: alias for '%H:%M:%S'
177  * - %%: a literal '%'
178  *
179  * @return a pointer to the first character not processed in this function
180  * call. In case the input string contains more characters than
181  * required by the format string the return value points right after
182  * the last consumed input character. In case the whole input string
183  * is consumed the return value points to the null byte at the end of
184  * the string. On failure NULL is returned.
185  */
186 char *av_small_strptime(const char *p, const char *fmt, struct tm *dt);
187 
188 /**
189  * Convert the decomposed UTC time in tm to a time_t value.
190  */
191 time_t av_timegm(struct tm *tm);
192 
193 #endif /* AVUTIL_PARSEUTILS_H */