cast/protocol/castv2/streaming_examples/capabilities_response.json

{
  "capabilities": {
    "keySystems": [],
    "mediaCaps": ["video", "h264", "vp8", "hevc", "vp9", "audio", "aac", "opus"]
  },
  "result": "ok",
  "seqNum": 820263770,
  "type": "CAPABILITIES_RESPONSE"
}