From 4cdf2c7f768015c74078544d153f243b6d9b9ac5 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Sat, 2 Dec 2023 00:26:03 +0100
Subject: [PATCH] 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>
---
 libavformat/mov.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/libavformat/mov.c b/libavformat/mov.c
index f7b5ec7a35..30cf7a15b0 100644
--- a/libavformat/mov.c
+++ b/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;