1 /*
2  * Various simple utilities for ffmpeg system
3  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 #include "avformat.h"
22 
23 /* add one element to a dynamic array */
ff_dynarray_add(unsigned long ** tab_ptr,int * nb_ptr,unsigned long elem)24 void ff_dynarray_add(unsigned long **tab_ptr, int *nb_ptr, unsigned long elem)
25 {
26     int nb, nb_alloc;
27     unsigned long *tab;
28 
29     nb = *nb_ptr;
30     tab = *tab_ptr;
31     if ((nb & (nb - 1)) == 0) {
32         if (nb == 0)
33             nb_alloc = 1;
34         else
35             nb_alloc = nb * 2;
36         tab = av_realloc(tab, nb_alloc * sizeof(unsigned long));
37         *tab_ptr = tab;
38     }
39     tab[nb++] = elem;
40     *nb_ptr = nb;
41 }
42 
mktimegm(struct tm * tm)43 time_t mktimegm(struct tm *tm)
44 {
45     time_t t;
46 
47     int y = tm->tm_year + 1900, m = tm->tm_mon + 1, d = tm->tm_mday;
48 
49     if (m < 3) {
50         m += 12;
51         y--;
52     }
53 
54     t = 86400 *
55         (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 + y / 400 - 719469);
56 
57     t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec;
58 
59     return t;
60 }
61 
62 #define ISLEAP(y) (((y) % 4 == 0) && (((y) % 100) != 0 || ((y) % 400) == 0))
63 #define LEAPS_COUNT(y) ((y)/4 - (y)/100 + (y)/400)
64 
65 /* This is our own gmtime_r. It differs from its POSIX counterpart in a
66    couple of places, though. */
brktimegm(time_t secs,struct tm * tm)67 struct tm *brktimegm(time_t secs, struct tm *tm)
68 {
69     int days, y, ny, m;
70     int md[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
71 
72     days = secs / 86400;
73     secs %= 86400;
74     tm->tm_hour = secs / 3600;
75     tm->tm_min = (secs % 3600) / 60;
76     tm->tm_sec =  secs % 60;
77 
78     /* oh well, may be someone some day will invent a formula for this stuff */
79     y = 1970; /* start "guessing" */
80     while (days >= (ISLEAP(y)?366:365)) {
81         ny = (y + days/366);
82         days -= (ny - y) * 365 + LEAPS_COUNT(ny - 1) - LEAPS_COUNT(y - 1);
83         y = ny;
84     }
85     md[1] = ISLEAP(y)?29:28;
86     for (m=0; days >= md[m]; m++)
87          days -= md[m];
88 
89     tm->tm_year = y;  /* unlike gmtime_r we store complete year here */
90     tm->tm_mon = m+1; /* unlike gmtime_r tm_mon is from 1 to 12 */
91     tm->tm_mday = days+1;
92 
93     return tm;
94 }
95 
96 /* get a positive number between n_min and n_max, for a maximum length
97    of len_max. Return -1 if error. */
date_get_num(const char ** pp,int n_min,int n_max,int len_max)98 static int date_get_num(const char **pp,
99                         int n_min, int n_max, int len_max)
100 {
101     int i, val, c;
102     const char *p;
103 
104     p = *pp;
105     val = 0;
106     for(i = 0; i < len_max; i++) {
107         c = *p;
108         if (!isdigit(c))
109             break;
110         val = (val * 10) + c - '0';
111         p++;
112     }
113     /* no number read ? */
114     if (p == *pp)
115         return -1;
116     if (val < n_min || val > n_max)
117         return -1;
118     *pp = p;
119     return val;
120 }
121 
122 /* small strptime for ffmpeg */
small_strptime(const char * p,const char * fmt,struct tm * dt)123 const char *small_strptime(const char *p, const char *fmt,
124                            struct tm *dt)
125 {
126     int c, val;
127 
128     for(;;) {
129         c = *fmt++;
130         if (c == '\0') {
131             return p;
132         } else if (c == '%') {
133             c = *fmt++;
134             switch(c) {
135             case 'H':
136                 val = date_get_num(&p, 0, 23, 2);
137                 if (val == -1)
138                     return NULL;
139                 dt->tm_hour = val;
140                 break;
141             case 'M':
142                 val = date_get_num(&p, 0, 59, 2);
143                 if (val == -1)
144                     return NULL;
145                 dt->tm_min = val;
146                 break;
147             case 'S':
148                 val = date_get_num(&p, 0, 59, 2);
149                 if (val == -1)
150                     return NULL;
151                 dt->tm_sec = val;
152                 break;
153             case 'Y':
154                 val = date_get_num(&p, 0, 9999, 4);
155                 if (val == -1)
156                     return NULL;
157                 dt->tm_year = val - 1900;
158                 break;
159             case 'm':
160                 val = date_get_num(&p, 1, 12, 2);
161                 if (val == -1)
162                     return NULL;
163                 dt->tm_mon = val - 1;
164                 break;
165             case 'd':
166                 val = date_get_num(&p, 1, 31, 2);
167                 if (val == -1)
168                     return NULL;
169                 dt->tm_mday = val;
170                 break;
171             case '%':
172                 goto match;
173             default:
174                 return NULL;
175             }
176         } else {
177         match:
178             if (c != *p)
179                 return NULL;
180             p++;
181         }
182     }
183     return p;
184 }
185 
186