avformat/mov: don't abort on duplicate Mastering Display Metadata boxes

The VP9 spec defines a SmDm box for this information, and the ISOBMFF spec defines a
mdvc one. If both are present, just ignore one of them.
This is in line with clli and CoLL boxes.

Fixes ticket #10711.

Signed-off-by: James Almer <jamrial@gmail.com>
(cherry picked from commit 189c32f536)

libavformat/mov.c

@@ -5916,8 +5916,10 @@ static int mov_read_smdm(MOVContext *c, AVIOContext *pb, MOVAtom atom)
         av_log(c->fc, AV_LOG_WARNING, "Unsupported Mastering Display Metadata box version %d\n", version);
         return 0;
     }
-    if (sc->mastering)
-        return AVERROR_INVALIDDATA;
+    if (sc->mastering) {
+        av_log(c->fc, AV_LOG_WARNING, "Ignoring duplicate Mastering Display Metadata\n");
+        return 0;
+    }
 
     avio_skip(pb, 3); /* flags */
 
@@ -5954,11 +5956,16 @@ static int mov_read_mdcv(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 
     sc = c->fc->streams[c->fc->nb_streams - 1]->priv_data;
 
-    if (atom.size < 24 || sc->mastering) {
+    if (atom.size < 24) {
         av_log(c->fc, AV_LOG_ERROR, "Invalid Mastering Display Color Volume box\n");
         return AVERROR_INVALIDDATA;
     }
 
+    if (sc->mastering) {
+        av_log(c->fc, AV_LOG_WARNING, "Ignoring duplicate Mastering Display Color Volume\n");
+        return 0;
+    }
+
     sc->mastering = av_mastering_display_metadata_alloc();
     if (!sc->mastering)
         return AVERROR(ENOMEM);