libavformat/cutils.c

   1 /*
   2  * Various simple utilities for ffmpeg system
   3  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19 #include "avformat.h"
  20
  21 #if !defined(CONFIG_NOCUTILS)
  22 /**
  23  * Return TRUE if val is a prefix of str. If it returns TRUE, ptr is
  24  * set to the next character in 'str' after the prefix.
  25  *
  26  * @param str input string
  27  * @param val prefix to test
  28  * @param ptr updated after the prefix in str in there is a match
  29  * @return TRUE if there is a match
  30  */
  31 int strstart(const char *str, const char *val, const char **ptr)
  32 {
  33     const char *p, *q;
  34     p = str;
  35     q = val;
  36     while (*q != '\0') {
  37         if (*p != *q)
  38             return 0;
  39         p++;
  40         q++;
  41     }
  42     if (ptr)
  43         *ptr = p;
  44     return 1;
  45 }
  46
  47 /**
  48  * Return TRUE if val is a prefix of str (case independent). If it
  49  * returns TRUE, ptr is set to the next character in 'str' after the
  50  * prefix.
  51  *
  52  * @param str input string
  53  * @param val prefix to test
  54  * @param ptr updated after the prefix in str in there is a match
  55  * @return TRUE if there is a match */
  56 int stristart(const char *str, const char *val, const char **ptr)
  57 {
  58     const char *p, *q;
  59     p = str;
  60     q = val;
  61     while (*q != '\0') {
  62         if (toupper(*(const unsigned char *)p) != toupper(*(const unsigned char *)q))
  63             return 0;
  64         p++;
  65         q++;
  66     }
  67     if (ptr)
  68         *ptr = p;
  69     return 1;
  70 }
  71
  72 /**
  73  * Copy the string str to buf. If str length is bigger than buf_size -
  74  * 1 then it is clamped to buf_size - 1.
  75  * NOTE: this function does what strncpy should have done to be
  76  * useful. NEVER use strncpy.
  77  *
  78  * @param buf destination buffer
  79  * @param buf_size size of destination buffer
  80  * @param str source string
  81  */
  82 void pstrcpy(char *buf, int buf_size, const char *str)
  83 {
  84     int c;
  85     char *q = buf;
  86
  87     if (buf_size <= 0)
  88         return;
  89
  90     for(;;) {
  91         c = *str++;
  92         if (c == 0 || q >= buf + buf_size - 1)
  93             break;
  94         *q++ = c;
  95     }
  96     *q = '\0';
  97 }
  98
  99 /* strcat and truncate. */
 100 char *pstrcat(char *buf, int buf_size, const char *s)
 101 {
 102     int len;
 103     len = strlen(buf);
 104     if (len < buf_size)
 105         pstrcpy(buf + len, buf_size - len, s);
 106     return buf;
 107 }
 108
 109 #endif
 110
 111 /* add one element to a dynamic array */
 112 void __dynarray_add(unsigned long **tab_ptr, int *nb_ptr, unsigned long elem)
 113 {
 114     int nb, nb_alloc;
 115     unsigned long *tab;
 116
 117     nb = *nb_ptr;
 118     tab = *tab_ptr;
 119     if ((nb & (nb - 1)) == 0) {
 120         if (nb == 0)
 121             nb_alloc = 1;
 122         else
 123             nb_alloc = nb * 2;
 124         tab = av_realloc(tab, nb_alloc * sizeof(unsigned long));
 125         *tab_ptr = tab;
 126     }
 127     tab[nb++] = elem;
 128     *nb_ptr = nb;
 129 }
 130
 131 time_t mktimegm(struct tm *tm)
 132 {
 133     time_t t;
 134
 135     int y = tm->tm_year + 1900, m = tm->tm_mon + 1, d = tm->tm_mday;
 136
 137     if (m < 3) {
 138         m += 12;
 139         y--;
 140     }
 141
 142     t = 86400 *
 143         (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 + y / 400 - 719469);
 144
 145     t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec;
 146
 147     return t;
 148 }
 149
 150 #define ISLEAP(y) (((y) % 4 == 0) && (((y) % 100) != 0 || ((y) % 400) == 0))
 151 #define LEAPS_COUNT(y) ((y)/4 - (y)/100 + (y)/400)
 152
 153 /* this is our own gmtime_r. it differs from its POSIX counterpart in a
 154    couple of places, though. */
 155 struct tm *brktimegm(time_t secs, struct tm *tm)
 156 {
 157     int days, y, ny, m;
 158     int md[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
 159
 160     days = secs / 86400;
 161     secs %= 86400;
 162     tm->tm_hour = secs / 3600;
 163     tm->tm_min = (secs % 3600) / 60;
 164     tm->tm_sec =  secs % 60;
 165
 166     /* oh well, may be someone some day will invent a formula for this stuff */
 167     y = 1970; /* start "guessing" */
 168     while (days >= (ISLEAP(y)?366:365)) {
 169         ny = (y + days/366);
 170         days -= (ny - y) * 365 + LEAPS_COUNT(ny - 1) - LEAPS_COUNT(y - 1);
 171         y = ny;
 172     }
 173     md[1] = ISLEAP(y)?29:28;
 174     for (m=0; days >= md[m]; m++)
 175          days -= md[m];
 176
 177     tm->tm_year = y;  /* unlike gmtime_r we store complete year here */
 178     tm->tm_mon = m+1; /* unlike gmtime_r tm_mon is from 1 to 12 */
 179     tm->tm_mday = days+1;
 180
 181     return tm;
 182 }
 183
 184 /* get a positive number between n_min and n_max, for a maximum length
 185    of len_max. Return -1 if error. */
 186 static int date_get_num(const char **pp,
 187                         int n_min, int n_max, int len_max)
 188 {
 189     int i, val, c;
 190     const char *p;
 191
 192     p = *pp;
 193     val = 0;
 194     for(i = 0; i < len_max; i++) {
 195         c = *p;
 196         if (!isdigit(c))
 197             break;
 198         val = (val * 10) + c - '0';
 199         p++;
 200     }
 201     /* no number read ? */
 202     if (p == *pp)
 203         return -1;
 204     if (val < n_min || val > n_max)
 205         return -1;
 206     *pp = p;
 207     return val;
 208 }
 209
 210 /* small strptime for ffmpeg */
 211 const char *small_strptime(const char *p, const char *fmt,
 212                            struct tm *dt)
 213 {
 214     int c, val;
 215
 216     for(;;) {
 217         c = *fmt++;
 218         if (c == '\0') {
 219             return p;
 220         } else if (c == '%') {
 221             c = *fmt++;
 222             switch(c) {
 223             case 'H':
 224                 val = date_get_num(&p, 0, 23, 2);
 225                 if (val == -1)
 226                     return NULL;
 227                 dt->tm_hour = val;
 228                 break;
 229             case 'M':
 230                 val = date_get_num(&p, 0, 59, 2);
 231                 if (val == -1)
 232                     return NULL;
 233                 dt->tm_min = val;
 234                 break;
 235             case 'S':
 236                 val = date_get_num(&p, 0, 59, 2);
 237                 if (val == -1)
 238                     return NULL;
 239                 dt->tm_sec = val;
 240                 break;
 241             case 'Y':
 242                 val = date_get_num(&p, 0, 9999, 4);
 243                 if (val == -1)
 244                     return NULL;
 245                 dt->tm_year = val - 1900;
 246                 break;
 247             case 'm':
 248                 val = date_get_num(&p, 1, 12, 2);
 249                 if (val == -1)
 250                     return NULL;
 251                 dt->tm_mon = val - 1;
 252                 break;
 253             case 'd':
 254                 val = date_get_num(&p, 1, 31, 2);
 255                 if (val == -1)
 256                     return NULL;
 257                 dt->tm_mday = val;
 258                 break;
 259             case '%':
 260                 goto match;
 261             default:
 262                 return NULL;
 263             }
 264         } else {
 265         match:
 266             if (c != *p)
 267                 return NULL;
 268             p++;
 269         }
 270     }
 271     return p;
 272 }
 273