mov: fix time types related to mov_metadata_creation_time

Fixes Ticket1817
Based on patch by: Przemyslaw Wesolek <przemyslaw.wesolek@go.art.pl>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/mov.c

@@ -780,14 +780,16 @@ static int mov_read_moof(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     return mov_read_default(c, pb, atom);
 }
 
-static void mov_metadata_creation_time(AVDictionary **metadata, time_t time)
+static void mov_metadata_creation_time(AVDictionary **metadata, int64_t time)
 {
     char buffer[32];
     if (time) {
         struct tm *ptm;
+        time_t timet;
         if(time >= 2082844800)
             time -= 2082844800;  /* seconds between 1904-01-01 and Epoch */
-        ptm = gmtime(&time);
+        timet = time;
+        ptm = gmtime(&timet);
         if (!ptm) return;
         strftime(buffer, sizeof(buffer), "%Y-%m-%d %H:%M:%S", ptm);
         av_dict_set(metadata, "creation_time", buffer, 0);
@@ -801,7 +803,7 @@ static int mov_read_mdhd(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     int version;
     char language[4] = {0};
     unsigned lang;
-    time_t creation_time;
+    int64_t creation_time;
 
     if (c->fc->nb_streams < 1)
         return 0;
@@ -836,7 +838,7 @@ static int mov_read_mdhd(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 
 static int mov_read_mvhd(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 {
-    time_t creation_time;
+    int64_t creation_time;
     int version = avio_r8(pb); /* version */
     avio_rb24(pb); /* flags */