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 */
24void ff_dynarray_add(intptr_t **tab_ptr, int *nb_ptr, intptr_t elem)
25{
26    int nb, nb_alloc;
27    intptr_t *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(intptr_t));
37        *tab_ptr = tab;
38    }
39    tab[nb++] = elem;
40    *nb_ptr = nb;
41}
42
43time_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. */
67struct 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 > 365) {
81        ny = (y + days/366);
82        days -= (ny - y) * 365 + LEAPS_COUNT(ny - 1) - LEAPS_COUNT(y - 1);
83        y = ny;
84    }
85    if (days==365 && !ISLEAP(y)) { days=0; y++; }
86    md[1] = ISLEAP(y)?29:28;
87    for (m=0; days >= md[m]; m++)
88         days -= md[m];
89
90    tm->tm_year = y;  /* unlike gmtime_r we store complete year here */
91    tm->tm_mon = m+1; /* unlike gmtime_r tm_mon is from 1 to 12 */
92    tm->tm_mday = days+1;
93
94    return tm;
95}
96
97/* get a positive number between n_min and n_max, for a maximum length
98   of len_max. Return -1 if error. */
99static int date_get_num(const char **pp,
100                        int n_min, int n_max, int len_max)
101{
102    int i, val, c;
103    const char *p;
104
105    p = *pp;
106    val = 0;
107    for(i = 0; i < len_max; i++) {
108        c = *p;
109        if (!isdigit(c))
110            break;
111        val = (val * 10) + c - '0';
112        p++;
113    }
114    /* no number read ? */
115    if (p == *pp)
116        return -1;
117    if (val < n_min || val > n_max)
118        return -1;
119    *pp = p;
120    return val;
121}
122
123/* small strptime for ffmpeg */
124const char *small_strptime(const char *p, const char *fmt,
125                           struct tm *dt)
126{
127    int c, val;
128
129    for(;;) {
130        c = *fmt++;
131        if (c == '\0') {
132            return p;
133        } else if (c == '%') {
134            c = *fmt++;
135            switch(c) {
136            case 'H':
137                val = date_get_num(&p, 0, 23, 2);
138                if (val == -1)
139                    return NULL;
140                dt->tm_hour = val;
141                break;
142            case 'M':
143                val = date_get_num(&p, 0, 59, 2);
144                if (val == -1)
145                    return NULL;
146                dt->tm_min = val;
147                break;
148            case 'S':
149                val = date_get_num(&p, 0, 59, 2);
150                if (val == -1)
151                    return NULL;
152                dt->tm_sec = val;
153                break;
154            case 'Y':
155                val = date_get_num(&p, 0, 9999, 4);
156                if (val == -1)
157                    return NULL;
158                dt->tm_year = val - 1900;
159                break;
160            case 'm':
161                val = date_get_num(&p, 1, 12, 2);
162                if (val == -1)
163                    return NULL;
164                dt->tm_mon = val - 1;
165                break;
166            case 'd':
167                val = date_get_num(&p, 1, 31, 2);
168                if (val == -1)
169                    return NULL;
170                dt->tm_mday = val;
171                break;
172            case '%':
173                goto match;
174            default:
175                return NULL;
176            }
177        } else {
178        match:
179            if (c != *p)
180                return NULL;
181            p++;
182        }
183    }
184    return p;
185}
186
187