mirror of https://git.ffmpeg.org/ffmpeg.git
58 lines
2.0 KiB
C
58 lines
2.0 KiB
C
/*
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* various simple utilities for libavformat
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* Copyright (c) 2000, 2001, 2002 Fabrice Bellard
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "avformat.h"
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#include "internal.h"
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#define ISLEAP(y) (((y) % 4 == 0) && (((y) % 100) != 0 || ((y) % 400) == 0))
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#define LEAPS_COUNT(y) ((y)/4 - (y)/100 + (y)/400)
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/* This is our own gmtime_r. It differs from its POSIX counterpart in a
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couple of places, though. */
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struct tm *ff_brktimegm(time_t secs, struct tm *tm)
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{
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int days, y, ny, m;
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int md[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
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days = secs / 86400;
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secs %= 86400;
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tm->tm_hour = secs / 3600;
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tm->tm_min = (secs % 3600) / 60;
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tm->tm_sec = secs % 60;
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/* oh well, may be someone some day will invent a formula for this stuff */
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y = 1970; /* start "guessing" */
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while (days > 365) {
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ny = (y + days/366);
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days -= (ny - y) * 365 + LEAPS_COUNT(ny - 1) - LEAPS_COUNT(y - 1);
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y = ny;
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}
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if (days==365 && !ISLEAP(y)) { days=0; y++; }
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md[1] = ISLEAP(y)?29:28;
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for (m=0; days >= md[m]; m++)
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days -= md[m];
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tm->tm_year = y; /* unlike gmtime_r we store complete year here */
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tm->tm_mon = m+1; /* unlike gmtime_r tm_mon is from 1 to 12 */
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tm->tm_mday = days+1;
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return tm;
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}
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