{
  "$ref": "core/room_event.json",
  "type": "m.call.sdp_stream_metadata_changed",
  "content": {
    "version": "1",
    "call_id": "1414213562373095",
    "party_id": "1732050807568877",
    "sdp_stream_metadata": {
        "2311546231": {
            "purpose": "m.usermedia",
            "audio_muted:": true,
            "video_muted": true
        }
    }
  }
}