avformat/mov: Ignore duplicate ftyp

Fixes: switch_1080p_720p.mp4
Found-by: Dale Curtis <dalecurtis@chromium.org>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 4cdf2c7f76)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/mov.c

@@ -1222,8 +1222,12 @@ static int mov_read_ftyp(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     int ret = ffio_read_size(pb, type, 4);
     if (ret < 0)
         return ret;
-    if (c->fc->nb_streams)
-        return AVERROR_INVALIDDATA;
+    if (c->fc->nb_streams) {
+        if (c->fc->strict_std_compliance >= FF_COMPLIANCE_STRICT)
+            return AVERROR_INVALIDDATA;
+        av_log(c->fc, AV_LOG_DEBUG, "Ignoring duplicate FTYP\n");
+        return 0;
+    }
 
     if (strcmp(type, "qt  "))
         c->isom = 1;