Add support for the TPOS/TPA (disc number) id3 tag.
diff --git a/include/media/mediametadataretriever.h b/include/media/mediametadataretriever.h
index 113c452..022b849 100644
--- a/include/media/mediametadataretriever.h
+++ b/include/media/mediametadataretriever.h
@@ -54,6 +54,7 @@
     METADATA_KEY_VIDEO_WIDTH     = 20,
     METADATA_KEY_WRITER          = 21,
     METADATA_KEY_MIMETYPE        = 22,
+    METADATA_KEY_DISC_NUMBER     = 23,
     // Add more here...
 };
 
diff --git a/include/media/stagefright/MetaData.h b/include/media/stagefright/MetaData.h
index 3b21468..8f423f7 100644
--- a/include/media/stagefright/MetaData.h
+++ b/include/media/stagefright/MetaData.h
@@ -59,6 +59,7 @@
     kKeyAlbumArtMIME      = 'alAM',  // cstring
     kKeyAuthor            = 'auth',  // cstring
     kKeyCDTrackNumber     = 'cdtr',  // cstring
+    kKeyDiscNumber        = 'dnum',  // cstring
     kKeyDate              = 'date',  // cstring
     kKeyWriter            = 'writ',  // cstring
 };