diff --git a/libavformat/asf.c b/libavformat/asf.c
index 455ca4d826..719cae9da5 100644
--- a/libavformat/asf.c
+++ b/libavformat/asf.c
@@ -147,6 +147,14 @@ const ff_asf_guid ff_asf_extended_stream_properties_object = {
     0xcb, 0xa5, 0xe6, 0x14, 0x72, 0xc6, 0x32, 0x43, 0x83, 0x99, 0xa9, 0x69, 0x52, 0x06, 0x5b, 0x5a
 };
 
+const ff_asf_guid ff_asf_group_mutual_exclusion_object = {
+    0x40, 0x5a, 0x46, 0xd1, 0x79, 0x5a, 0x38, 0x43, 0xb7, 0x1b, 0xe3, 0x6b, 0x8f, 0xd6, 0xc2, 0x49
+};
+
+const ff_asf_guid ff_asf_mutex_language = {
+    0x00, 0x2a, 0xe2, 0xd6, 0xda, 0x35, 0xd1, 0x11, 0x90, 0x34, 0x00, 0xa0, 0xc9, 0x03, 0x49, 0xbe
+};
+
 /* List of official tags at http://msdn.microsoft.com/en-us/library/dd743066(VS.85).aspx */
 const AVMetadataConv ff_asf_metadata_conv[] = {
     { "WM/AlbumArtist",          "album_artist"     },
diff --git a/libavformat/asf.h b/libavformat/asf.h
index 914ddef48e..43288ddbaf 100644
--- a/libavformat/asf.h
+++ b/libavformat/asf.h
@@ -100,6 +100,8 @@ extern const ff_asf_guid ff_asf_content_encryption;
 extern const ff_asf_guid ff_asf_ext_content_encryption;
 extern const ff_asf_guid ff_asf_digital_signature;
 extern const ff_asf_guid ff_asf_extended_stream_properties_object;
+extern const ff_asf_guid ff_asf_group_mutual_exclusion_object;
+extern const ff_asf_guid ff_asf_mutex_language;
 
 extern const AVMetadataConv ff_asf_metadata_conv[];
 
diff --git a/libavformat/asfenc.c b/libavformat/asfenc.c
index 14f92e258f..66551ea373 100644
--- a/libavformat/asfenc.c
+++ b/libavformat/asfenc.c
@@ -396,6 +396,7 @@ static int asf_write_header1(AVFormatContext *s, int64_t file_size,
     int64_t header_offset, cur_pos, hpos;
     int bit_rate;
     int64_t duration;
+    int audio_language_counts[128] = { 0 };
 
     ff_metadata_conv(&s->metadata, ff_asf_metadata_conv, NULL);
 
@@ -444,6 +445,8 @@ static int asf_write_header1(AVFormatContext *s, int64_t file_size,
                     asf->streams[n].stream_language_index = asf->nb_languages;
                     asf->nb_languages++;
                 }
+                if (enc->codec_type == AVMEDIA_TYPE_AUDIO)
+                    audio_language_counts[asf->streams[n].stream_language_index]++;
             }
         } else {
             asf->streams[n].stream_language_index = 128;
@@ -484,6 +487,7 @@ static int asf_write_header1(AVFormatContext *s, int64_t file_size,
     if (asf->nb_languages) {
         int64_t hpos2;
         int i;
+        int nb_audio_languages = 0;
 
         hpos2 = put_header(pb, &ff_asf_language_guid);
         avio_wl16(pb, asf->nb_languages);
@@ -493,6 +497,25 @@ static int asf_write_header1(AVFormatContext *s, int64_t file_size,
         }
         end_header(pb, hpos2);
 
+        for (i = 0; i < asf->nb_languages; i++)
+            if (audio_language_counts[i])
+                nb_audio_languages++;
+
+        if (nb_audio_languages > 1) {
+            hpos2 = put_header(pb, &ff_asf_group_mutual_exclusion_object);
+            ff_put_guid(pb, &ff_asf_mutex_language);
+            avio_wl16(pb, nb_audio_languages);
+            for (i = 0; i < asf->nb_languages; i++) {
+                if (audio_language_counts[i]) {
+                    avio_wl16(pb, audio_language_counts[i]);
+                    for (n = 0; n < s->nb_streams; n++)
+                        if (asf->streams[n].stream_language_index == i && s->streams[n]->codec->codec_type == AVMEDIA_TYPE_AUDIO)
+                            avio_wl16(pb, n + 1);
+                }
+            }
+            end_header(pb, hpos2);
+        }
+
         for (n = 0; n < s->nb_streams; n++) {
             int64_t es_pos;
             if (asf->streams[n].stream_language_index > 127)