1{
2  "capabilities": {
3    "keySystems": [],
4    "mediaCaps": ["video", "h264", "vp8", "hevc", "vp9", "audio", "aac", "opus"]
5  },
6  "result": "ok",
7  "seqNum": 820263770,
8  "type": "CAPABILITIES_RESPONSE"
9}