Amazon Kinesis Video StreamsのWebRTCとAlexaを組み合わせてドアホンみたいのを作る

import base64
import boto3
import json
import logging
import time
import uuid

CHANNEL_ARN = "<<WebRTCのシグナリングチャネルのARNを指定する>>"

logger = logging.getLogger()
logger.setLevel(logging.INFO)

def get_uuid():
    return str(uuid.uuid4())

def lambda_handler(request, context):
    logger.info("Request ->")
    logger.info(json.dumps(request, indent=2, sort_keys=True))

    if request["directive"]["header"]["name"] == "Discover":
        response = handle_discovery(request)
    elif request["directive"]["header"]["name"] == "InitiateSessionWithOffer":
        response = handle_initiate_session(request)
    elif request["directive"]["header"]["name"] == "SessionDisconnected":
        response = handle_session_disconnected(request)
    else:
        raise Exception("not implemented")

    logger.info("Response ->")
    logger.info(json.dumps(response, indent=2, sort_keys=True))

    return response

def handle_discovery(request):

    response = {
        "event": {
            "header": {
                "namespace":"Alexa.Discovery",
                "name":"Discover.Response",
                "payloadVersion": "3",
                "messageId": get_uuid()
            },
            "payload":{
                "endpoints":[
                    {
                        "endpointId": "kvs_webrtc_test",
                        "manufacturerName": "sparkgene.com",
                        "description": "test kvs webrtc camera",
                        "friendlyName": "玄関のカメラ",
                        "displayCategories": [ "CAMERA" ],
                        "cookie": {},
                        "capabilities": [
                            {
                                "type": "AlexaInterface",
                                "interface": "Alexa.RTCSessionController",
                                "version": "3",
                                "configuration": {
                                    "isFullDuplexAudioSupported": True
                                }
                            },
                            {
                                "type": "AlexaInterface",
                                "interface": "Alexa",
                                "version": "3"
                            }
                        ]
                    }
                ]
            }
        }
    }

    return response

def handle_initiate_session(request):
    kv_client = boto3.client('kinesisvideo', region_name="ap-northeast-1")
    res = kv_client.get_signaling_channel_endpoint(
        ChannelARN=CHANNEL_ARN,
        SingleMasterChannelEndpointConfiguration={
            "Protocols": [
                "HTTPS",
            ],
            "Role": "VIEWER"
        }
    )
    kvs_client = boto3.client('kinesis-video-signaling',
                            region_name="ap-northeast-1",
                            endpoint_url=res["ResourceEndpointList"][0]["ResourceEndpoint"])
    offer = {
        "type":"offer",
        "sdp": request["directive"]["payload"]["offer"]["value"]
    }

    answer_res = kvs_client.send_alexa_offer_to_master(
            ChannelARN=CHANNEL_ARN,
            SenderClientId="ProducerMaster",
            MessagePayload=base64.b64encode( json.dumps(offer).encode() ).decode()
        )
#    logger.debug(answer_res)
    if "Answer" in answer_res:
        sdp_answer = json.loads(base64.b64decode( answer_res["Answer"] ).decode('utf-8'))["sdp"]
    else:
        sdp_answer = None
    response = {
        "event": {
            "header": {
                "namespace": "Alexa.RTCSessionController",
                "name": "AnswerGeneratedForSession",
                "messageId": get_uuid(),
                "correlationToken": request["directive"]["header"]["correlationToken"],
                "payloadVersion": "3"
            },
            "endpoint": {
                "scope": {
                    "type": "BearerToken",
                    "token": request["directive"]["endpoint"]["scope"]["token"]
                },
                "endpointId": request["directive"]["endpoint"]["endpointId"]
            },
            "payload": {
                "answer": {
                    "format" : "SDP",
                    "value" : sdp_answer
                }
            }
        }
    }
#    logger.info(response)
    return response

def handle_session_disconnected(request):
    response = {
        "event": {
            "header": {
                "namespace": "Alexa.RTCSessionController",
                "name": "SessionDisconnected",
                "messageId": get_uuid(),
                "correlationToken": request["directive"]["header"]["correlationToken"],
                "payloadVersion": "3"
            },
            "endpoint": {
                "scope": {
                    "type": "BearerToken",
                    "token": request["directive"]["endpoint"]["scope"]["token"]
                },
                "endpointId": request["directive"]["endpoint"]["endpointId"]
            },
            "payload": {
                "sessionId": request["directive"]["payload"]["sessionId"]
            }
        }
    }

#    logger.info(response)
    return response

"autovideosrc num-buffers=1000 ! queue ! videoconvert ! clockoverlay time-format="%Y-%m-%d %H:%M:%S" font-desc="Sans 28" draw-outline=false ! videoscale ! video/x-raw,width=320,height=180,framerate=30/1 ! x264enc bframes=0 speed-preset=veryfast key-int-max=30 bitrate=512 ! "