PlayAudioAndGetDigits

播放音訊並收集 DTMF 數字。如果發生故障，例如使用者未輸入正確的 DTMF 位數，動作會播放「失敗」音訊，然後重播主要音訊，直到 SIP 媒體應用程式耗盡 Repeat 參數中定義的嘗試次數。

您必須從 S3 儲存貯體播放音訊檔案。S3 儲存貯體必須屬於與 SIP 媒體應用程式相同的 AWS 帳戶。此外，您必須將s3:GetObject許可授予 Amazon Chime SDK Voice Connector 服務主體 voiceconnector.chime.amazonaws.com。您可以使用 S3 主控台或 CLI 來執行此操作。

下列程式碼範例顯示典型的 S3 儲存貯體政策。

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "SMARead",
            "Effect": "Allow",
            "Principal": {
                "Service": "voiceconnector.chime.amazonaws.com"
            },
            "Action": [
                "s3:GetObject"
            ],
            "Resource": "arn:aws:s3:::bucket-name/*",
                "Condition": {
                "StringEquals": {
                    "aws:SourceAccount": "aws-account-id"
                }
            }
        }
    ]
}

Audio Service 會代表 Sip Media Application 讀取和寫入您的 S3 儲存貯體。若要避免混淆代理人問題，您可以限制 S3 儲存貯體存取單一 SIP 媒體應用程式。

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "SMARead",
            "Effect": "Allow",
            "Principal": {
                "Service": "voiceconnector.chime.amazonaws.com"
            },
            "Action": [
                "s3:GetObject"
            ],
            "Resource": "arn:aws:s3:::bucket-name/*",
                "Condition": {
                "StringEquals": {
                    "aws:SourceAccount": "aws-account-id",
                    "aws:SourceArn": "arn:aws:chime:region:aws-account-id:sma/sip-media-application-id"
                }
            }
        }
    ]
}

下列範例顯示典型PlayAudioAndGetDigits的動作。

{
    "Type" : "PlayAudioAndGetDigits",
    "Parameters" : {
        "CallId": "call-id-1",
        "ParticipantTag": "LEG-A"      
        "InputDigitsRegex": "^\d{2}#$",
        "AudioSource": {
            "Type": "S3",
            "BucketName": "bucket-name",
            "Key": "audio-file-1.wav"
        },
        "FailureAudioSource": {
            "Type": "S3",
            "BucketName": "bucket-name",
            "Key": "audio-file-failure.wav"
        },
        "MinNumberOfDigits": 3,
        "MaxNumberOfDigits": 5,
        "TerminatorDigits": ["#"],        
        "InBetweenDigitsDurationInMilliseconds": 5000,
        "Repeat": 3,
        "RepeatDurationInMilliseconds": 10000
    }
}

SIP 媒體應用程式一律會在執行 PlayAudioAndGetDigits動作後呼叫其 AWS Lambda 函數，並使用 ACTION_SUCCESSFUL或 ACTION_FAILED 呼叫事件類型。當應用程式成功收集數字時，它會設定 ActionData 物件中的ReceivedDigits值。下列範例顯示該 AWS Lambda 函數的調用事件結構。

{
    "SchemaVersion": "1.0",
    "Sequence": 3,
    "InvocationEventType": "ACTION_SUCCESSFUL",
    "ActionData": {
        "Type": "PlayAudioAndGetDigits",
        "Parameters" : {
            "CallId": "call-id-1",
            "ParticipantTag": "LEG-A",
            "InputDigitsRegex": "^\d{2}#$",
            "AudioSource": {
                "Type": "S3",
                "BucketName": "bucket-name",
                "Key": "audio-file-1.wav"
            },
            "FailureAudioSource": {
                "Type": "S3",
                "BucketName": "bucket-name",
                "Key": "audio-file-failure.wav"
            },
            "MinNumberOfDigits": 3,
            "MaxNumberOfDigits": 5,
            "TerminatorDigits": ["#"],
            "InBetweenDigitsDurationInMilliseconds": 5000,
            "Repeat": 3,
            "RepeatDurationInMilliseconds": 10000
        },
        "ErrorType": "InvalidAudioSource",
        "ErrorMessage": "Audio Source parameter value is invalid."
    },
        "ReceivedDigits": "1234"
    },
    "CallDetails": {
        ...
    }
}

錯誤處理

發生驗證錯誤時，SIP 媒體應用程式會使用 AWS Lambda 對應的錯誤訊息呼叫 函數。下表列出可能的錯誤訊息。

當動作因為逾時或重試次數過多而無法收集指定的位數時，SIP 媒體應用程式會使用ACTION_FAILED叫用事件類型叫用 AWS Lambda 函數。

{
    "SchemaVersion": "1.0",
    "Sequence": 4,
    "InvocationEventType": "ACTION_FAILED",
    "ActionData": {
        "Type": "PlayAudioAndGetDigits",
        "Parameters" : {
            "CallId": "call-id-1",
            "ParticipantTag": "LEG-A",
            "InputDigitsRegex": "^\d{2}#$",
            "AudioSource": {
                "Type": "S3",
                "BucketName": "bucket-name",
                "Key": "audio-file-1.wav"
            },
            "FailureAudioSource": {
                "Type": "S3",
                "BucketName": "bucket-name",
                "Key": "audio-file-failure.wav"
            },
            "MinNumberOfDigits": 3,
            "MaxNumberOfDigits": 5,
            "TerminatorDigits": ["#"],
            "InBetweenDigitsDurationInMilliseconds": 5000,
            "Repeat": 3,
            "RepeatDurationInMilliseconds": 10000
        },
        "ErrorType": "InvalidAudioSource",
        "ErrorMessage": "Audio Source parameter value is invalid."
    }
    "CallDetails": {
        ...
    }
}

請參閱 GitHub 上的工作範例：