summaryrefslogtreecommitdiff
path: root/libavformat/cutils.c
blob: 4967d5b90c211a23823a66e7f4d087a2666964a9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
/*
 * Various simple utilities for ffmpeg system
 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
 *
 * 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
 */
#include "avformat.h"

/* add one element to a dynamic array */
void ff_dynarray_add(intptr_t **tab_ptr, int *nb_ptr, intptr_t elem)
{
    int nb, nb_alloc;
    intptr_t *tab;

    nb = *nb_ptr;
    tab = *tab_ptr;
    if ((nb & (nb - 1)) == 0) {
        if (nb == 0)
            nb_alloc = 1;
        else
            nb_alloc = nb * 2;
        tab = av_realloc(tab, nb_alloc * sizeof(intptr_t));
        *tab_ptr = tab;
    }
    tab[nb++] = elem;
    *nb_ptr = nb;
}

time_t mktimegm(struct tm *tm)
{
    time_t t;

    int y = tm->tm_year + 1900, m = tm->tm_mon + 1, d = tm->tm_mday;

    if (m < 3) {
        m += 12;
        y--;
    }

    t = 86400 *
        (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 + y / 400 - 719469);

    t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec;

    return t;
}

#define ISLEAP(y) (((y) % 4 == 0) && (((y) % 100) != 0 || ((y) % 400) == 0))
#define LEAPS_COUNT(y) ((y)/4 - (y)/100 + (y)/400)

/* This is our own gmtime_r. It differs from its POSIX counterpart in a
   couple of places, though. */
struct tm *brktimegm(time_t secs, struct tm *tm)
{
    int days, y, ny, m;
    int md[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

    days = secs / 86400;
    secs %= 86400;
    tm->tm_hour = secs / 3600;
    tm->tm_min = (secs % 3600) / 60;
    tm->tm_sec =  secs % 60;

    /* oh well, may be someone some day will invent a formula for this stuff */
    y = 1970; /* start "guessing" */
    while (days > 365) {
        ny = (y + days/366);
        days -= (ny - y) * 365 + LEAPS_COUNT(ny - 1) - LEAPS_COUNT(y - 1);
        y = ny;
    }
    if (days==365 && !ISLEAP(y)) { days=0; y++; }
    md[1] = ISLEAP(y)?29:28;
    for (m=0; days >= md[m]; m++)
         days -= md[m];

    tm->tm_year = y;  /* unlike gmtime_r we store complete year here */
    tm->tm_mon = m+1; /* unlike gmtime_r tm_mon is from 1 to 12 */
    tm->tm_mday = days+1;

    return tm;
}

/* get a positive number between n_min and n_max, for a maximum length
   of len_max. Return -1 if error. */
static int date_get_num(const char **pp,
                        int n_min, int n_max, int len_max)
{
    int i, val, c;
    const char *p;

    p = *pp;
    val = 0;
    for(i = 0; i < len_max; i++) {
        c = *p;
        if (!isdigit(c))
            break;
        val = (val * 10) + c - '0';
        p++;
    }
    /* no number read ? */
    if (p == *pp)
        return -1;
    if (val < n_min || val > n_max)
        return -1;
    *pp = p;
    return val;
}

/* small strptime for ffmpeg */
const char *small_strptime(const char *p, const char *fmt,
                           struct tm *dt)
{
    int c, val;

    for(;;) {
        c = *fmt++;
        if (c == '\0') {
            return p;
        } else if (c == '%') {
            c = *fmt++;
            switch(c) {
            case 'H':
                val = date_get_num(&p, 0, 23, 2);
                if (val == -1)
                    return NULL;
                dt->tm_hour = val;
                break;
            case 'M':
                val = date_get_num(&p, 0, 59, 2);
                if (val == -1)
                    return NULL;
                dt->tm_min = val;
                break;
            case 'S':
                val = date_get_num(&p, 0, 59, 2);
                if (val == -1)
                    return NULL;
                dt->tm_sec = val;
                break;
            case 'Y':
                val = date_get_num(&p, 0, 9999, 4);
                if (val == -1)
                    return NULL;
                dt->tm_year = val - 1900;
                break;
            case 'm':
                val = date_get_num(&p, 1, 12, 2);
                if (val == -1)
                    return NULL;
                dt->tm_mon = val - 1;
                break;
            case 'd':
                val = date_get_num(&p, 1, 31, 2);
                if (val == -1)
                    return NULL;
                dt->tm_mday = val;
                break;
            case '%':
                goto match;
            default:
                return NULL;
            }
        } else {
        match:
            if (c != *p)
                return NULL;
            p++;
        }
    }
    return p;
}