Index: /trunk/src/VBox/Main/src-client/EbmlWriter.cpp
===================================================================
--- /trunk/src/VBox/Main/src-client/EbmlWriter.cpp	(revision 65258)
+++ /trunk/src/VBox/Main/src-client/EbmlWriter.cpp	(revision 65259)
@@ -383,4 +383,5 @@
     int AddAudioTrack(float fSamplingHz, float fOutputHz, uint8_t cChannels, uint8_t cBitDepth)
     {
+#ifdef VBOX_WITH_AUDIO_VIDEOREC
         m_Ebml.subStart(TrackEntry);
         m_Ebml.serializeUnsignedInteger(TrackNumber, (uint8_t)m_lstTracks.size());
@@ -406,4 +407,8 @@
 
         return VINF_SUCCESS;
+#else
+        RT_NOREF(fSamplingHz, fOutputHz, cChannels, cBitDepth);
+        return VERR_NOT_SUPPORTED;
+#endif
     }