diff --git a/ext/smoothstreaming/gstmssmanifest.c b/ext/smoothstreaming/gstmssmanifest.c
index e8824373c0..85f3da271a 100644
--- a/ext/smoothstreaming/gstmssmanifest.c
+++ b/ext/smoothstreaming/gstmssmanifest.c
@@ -597,23 +597,34 @@ _gst_mss_stream_audio_caps_from_qualitylevel_xml (GstMssStreamQuality * q)
     block_align = (int) g_ascii_strtoull (block_align_str, NULL, 10);
 
   if (!codec_data) {
-    GstMapInfo mapinfo;
+    gint codec_data_len;
     codec_data_str = (gchar *) xmlGetProp (node, (xmlChar *) "WaveFormatEx");
-    if (codec_data_str && strlen (codec_data_str)) {
+    codec_data_len = strlen (codec_data_str) / 2;
+
+    /* a WAVEFORMATEX structure is 18 bytes */
+    if (codec_data_str && codec_data_len >= 18) {
+      GstMapInfo mapinfo;
       codec_data = gst_buffer_from_hex_string ((gchar *) codec_data_str);
 
-      /* since this is a waveformatex, try to get the block_align and rate */
+      /* since this is a WAVEFORMATEX, try to get the block_align and rate */
       gst_buffer_map (codec_data, &mapinfo, GST_MAP_READ);
-      if (mapinfo.size >= 14) {
-        if (!channels_str) {
-          channels = GST_READ_UINT16_LE (mapinfo.data + 2);
-        }
-        if (!rate_str) {
-          rate = GST_READ_UINT32_LE (mapinfo.data + 4);
-        }
+      if (!channels_str) {
+        channels = GST_READ_UINT16_LE (mapinfo.data + 2);
+      }
+      if (!rate_str) {
+        rate = GST_READ_UINT32_LE (mapinfo.data + 4);
+      }
+      if (!block_align) {
         block_align = GST_READ_UINT16_LE (mapinfo.data + 12);
       }
       gst_buffer_unmap (codec_data, &mapinfo);
+
+      /* Consume all the WAVEFORMATEX structure, and pass only the rest of
+       * the data as the codec private data */
+      gst_buffer_resize (codec_data, 18, -1);
+    } else {
+      GST_WARNING ("Dropping WaveFormatEx: data is %d bytes, "
+          "but at least 18 bytes are expected", codec_data_len);
     }
   }