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Amazon Rekognition
Developer Guide

StartLabelDetection

Starts asynchronous detection of labels in a stored video.

Amazon Rekognition Video can detect labels in a video. Labels are instances of real-world entities. This includes objects like flower, tree, and table; events like wedding, graduation, and birthday party; concepts like landscape, evening, and nature; and activities like a person getting out of a car or a person skiing.

The video must be stored in an Amazon S3 bucket. Use Video to specify the bucket name and the filename of the video. StartLabelDetection returns a job identifier (JobId) which you use to get the results of the operation. When label detection is finished, Amazon Rekognition Video publishes a completion status to the Amazon Simple Notification Service topic that you specify in NotificationChannel.

To get the results of the label detection operation, first check that the status value published to the Amazon SNS topic is SUCCEEDED. If so, call GetLabelDetection and pass the job identifier (JobId) from the initial call to StartLabelDetection.

Request Syntax

{ "ClientRequestToken": "string", "JobTag": "string", "MinConfidence": number, "NotificationChannel": { "RoleArn": "string", "SNSTopicArn": "string" }, "Video": { "S3Object": { "Bucket": "string", "Name": "string", "Version": "string" } } }

Request Parameters

The request accepts the following data in JSON format.

ClientRequestToken

Idempotent token used to identify the start request. If you use the same token with multiple StartLabelDetection requests, the same JobId is returned. Use ClientRequestToken to prevent the same job from being accidently started more than once.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 64.

Pattern: ^[a-zA-Z0-9-_]+$

Required: No

JobTag

Unique identifier you specify to identify the job in the completion status published to the Amazon Simple Notification Service topic.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 256.

Pattern: [a-zA-Z0-9_.\-:]+

Required: No

MinConfidence

Specifies the minimum confidence that Amazon Rekognition Video must have in order to return a detected label. Confidence represents how certain Amazon Rekognition is that a label is correctly identified.0 is the lowest confidence. 100 is the highest confidence. Amazon Rekognition Video doesn't return any labels with a confidence level lower than this specified value.

If you don't specify MinConfidence, the operation returns labels with confidence values greater than or equal to 50 percent.

Type: Float

Valid Range: Minimum value of 0. Maximum value of 100.

Required: No

NotificationChannel

The Amazon SNS topic ARN you want Amazon Rekognition Video to publish the completion status of the label detection operation to.

Type: NotificationChannel object

Required: No

Video

The video in which you want to detect labels. The video must be stored in an Amazon S3 bucket.

Type: Video object

Required: Yes

Response Syntax

{ "JobId": "string" }

Response Elements

If the action is successful, the service sends back an HTTP 200 response.

The following data is returned in JSON format by the service.

JobId

The identifier for the label detection job. Use JobId to identify the job in a subsequent call to GetLabelDetection.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 64.

Pattern: ^[a-zA-Z0-9-_]+$

Errors

AccessDeniedException

You are not authorized to perform the action.

HTTP Status Code: 400

IdempotentParameterMismatchException

A ClientRequestToken input parameter was reused with an operation, but at least one of the other input parameters is different from the previous call to the operation.

HTTP Status Code: 400

InternalServerError

Amazon Rekognition experienced a service issue. Try your call again.

HTTP Status Code: 500

InvalidParameterException

Input parameter violated a constraint. Validate your parameter before calling the API operation again.

HTTP Status Code: 400

InvalidS3ObjectException

Amazon Rekognition is unable to access the S3 object specified in the request.

HTTP Status Code: 400

LimitExceededException

An Amazon Rekognition service limit was exceeded. For example, if you start too many Amazon Rekognition Video jobs concurrently, calls to start operations (StartLabelDetection, for example) will raise a LimitExceededException exception (HTTP status code: 400) until the number of concurrently running jobs is below the Amazon Rekognition service limit.

HTTP Status Code: 400

ProvisionedThroughputExceededException

The number of requests exceeded your throughput limit. If you want to increase this limit, contact Amazon Rekognition.

HTTP Status Code: 400

ThrottlingException

Amazon Rekognition is temporarily unable to process the request. Try your call again.

HTTP Status Code: 500

VideoTooLargeException

The file size or duration of the supplied media is too large. The maximum file size is 8GB. The maximum duration is 2 hours.

HTTP Status Code: 400

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following: