mp4a box contains mp3 audio when the object type indication is 0x6b

In this case, the MediaExtractor returns ERROR_UNSUPPORTED since our
software MP3 audio decoder may not be able to handle packetized
MP3 audio.

bug - 3377570

Change-Id: I8bb6b3813716b5fa019e318842e8e1908b3c8bf8
diff --git a/media/libstagefright/MPEG4Extractor.cpp b/media/libstagefright/MPEG4Extractor.cpp
index cf4cbe5..7b96d01 100644
--- a/media/libstagefright/MPEG4Extractor.cpp
+++ b/media/libstagefright/MPEG4Extractor.cpp
@@ -1596,6 +1596,14 @@
         return OK;
     }
 
+    if (objectTypeIndication  == 0x6b) {
+        // The media subtype is MP3 audio
+        // Our software MP3 audio decoder may not be able to handle
+        // packetized MP3 audio; for now, lets just return ERROR_UNSUPPORTED
+        LOGE("MP3 track in MP4/3GPP file is not supported");
+        return ERROR_UNSUPPORTED;
+    }
+
     const uint8_t *csd;
     size_t csd_size;
     if (esds.getCodecSpecificInfo(