title: Multiple XAudio2 instances needed for AUDIO_STREAM_CATEGORY?
body: <p>In the newer XAudio2 API's for Windows 8 and 10, an <a href="https://docs.microsoft.com/en-us/windows/win32/api/audiosessiontypes/ne-audiosessiontypes-audio_stream_category" rel="nofollow noreferrer"><code>AUDIO_STREAM_CATEGORY</code></a> is passed to <code>IXAudio2::CreateMasteringVoice</code>.</p>
  <p>The documentation goes on to say how these should be used for different types of audio. However an <code>IXAudio2</code> is only allowed one master voice. To do this is completely separate <code>IXAudio2</code> instances along with all associated interfaces required, or can categories be specified elsewhere in the audio graph by some means?</p>
  <blockquote>
  <p>Games should categorize their music streams as <strong>AudioCategory_GameMedia</strong> so that game music mutes automatically if another application plays music in the background. Music or video applications should categorize their streams as <strong>AudioCategory_Media</strong> or <strong>AudioCategory_Movie</strong> so they will take priority over <strong>AudioCategory_GameMedia</strong> streams. Game audio for in-game cinematics or cutscenes, when the audio is premixed or for creative reasons should take priority over background audio, should also be categorized as <strong>Media</strong> or <strong>Movie</strong>.</p>
  </blockquote>