* replacing calls to not-always-available gmtime_r with our own code.

     The new helper function actually differs in semantics from gmtime_r,
     so if that seems to be a problem I can actually move it to dv.c
     completely, since only DV muxer uses the code anyway.

Originally committed as revision 3399 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 34 insertions, 0 deletions

diff --git a/libavformat/cutils.c b/libavformat/cutils.c
index c31e5b5c17..1415e4e392 100644
--- a/libavformat/cutils.c
+++ b/libavformat/cutils.c
@@ -147,6 +147,40 @@ time_t mktimegm(struct tm *tm)
     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 >= (ISLEAP(y)?366:365)) {
+	ny = (y + days/366);
+	days -= (ny - y) * 365 + LEAPS_COUNT(ny - 1) - LEAPS_COUNT(y - 1);
+	y = ny;
+    }
+    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,