| 1 | /* |
| 2 | * various simple utilities for libavformat |
| 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 | #include "internal.h" |
| 23 | |
| 24 | #define ISLEAP(y) (((y) % 4 == 0) && (((y) % 100) != 0 || ((y) % 400) == 0)) |
| 25 | #define LEAPS_COUNT(y) ((y)/4 - (y)/100 + (y)/400) |
| 26 | |
| 27 | /* This is our own gmtime_r. It differs from its POSIX counterpart in a |
| 28 | couple of places, though. */ |
| 29 | struct tm *ff_brktimegm(time_t secs, struct tm *tm) |
| 30 | { |
| 31 | int days, y, ny, m; |
| 32 | int md[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; |
| 33 | |
| 34 | days = secs / 86400; |
| 35 | secs %= 86400; |
| 36 | tm->tm_hour = secs / 3600; |
| 37 | tm->tm_min = (secs % 3600) / 60; |
| 38 | tm->tm_sec = secs % 60; |
| 39 | |
| 40 | /* oh well, may be someone some day will invent a formula for this stuff */ |
| 41 | y = 1970; /* start "guessing" */ |
| 42 | while (days > 365) { |
| 43 | ny = (y + days/366); |
| 44 | days -= (ny - y) * 365 + LEAPS_COUNT(ny - 1) - LEAPS_COUNT(y - 1); |
| 45 | y = ny; |
| 46 | } |
| 47 | if (days==365 && !ISLEAP(y)) { days=0; y++; } |
| 48 | md[1] = ISLEAP(y)?29:28; |
| 49 | for (m=0; days >= md[m]; m++) |
| 50 | days -= md[m]; |
| 51 | |
| 52 | tm->tm_year = y; /* unlike gmtime_r we store complete year here */ |
| 53 | tm->tm_mon = m+1; /* unlike gmtime_r tm_mon is from 1 to 12 */ |
| 54 | tm->tm_mday = days+1; |
| 55 | |
| 56 | return tm; |
| 57 | } |