startFaceDetection method

Future<StartFaceDetectionResponse> startFaceDetection({ required Video video, String? clientRequestToken, FaceAttributes? faceAttributes, String? jobTag, NotificationChannel? notificationChannel, })

Starts asynchronous detection of faces in a stored video.

Amazon Rekognition Video can detect faces in a video stored in an Amazon S3 bucket. Use Video to specify the bucket name and the filename of the video. StartFaceDetection returns a job identifier (JobId) that you use to get the results of the operation. When face 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 face detection operation, first check that the status value published to the Amazon SNS topic is SUCCEEDED. If so, call GetFaceDetection and pass the job identifier (JobId) from the initial call to StartFaceDetection.

For more information, see Detecting Faces in a Stored Video in the Amazon Rekognition Developer Guide.

May throw AccessDeniedException. May throw IdempotentParameterMismatchException. May throw InvalidParameterException. May throw InvalidS3ObjectException. May throw InternalServerError. May throw VideoTooLargeException. May throw ProvisionedThroughputExceededException. May throw LimitExceededException. May throw ThrottlingException.

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

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

Parameter faceAttributes : The face attributes you want returned.

DEFAULT - The following subset of facial attributes are returned: BoundingBox, Confidence, Pose, Quality and Landmarks.

ALL - All facial attributes are returned.

Parameter jobTag : An identifier you specify that's returned in the completion notification that's published to your Amazon Simple Notification Service topic. For example, you can use JobTag to group related jobs and identify them in the completion notification.

Parameter notificationChannel : The ARN of the Amazon SNS topic to which you want Amazon Rekognition Video to publish the completion status of the face detection operation.

Implementation

Future<StartFaceDetectionResponse> startFaceDetection({
  required Video video,
  String? clientRequestToken,
  FaceAttributes? faceAttributes,
  String? jobTag,
  NotificationChannel? notificationChannel,
}) async {
  ArgumentError.checkNotNull(video, 'video');
  _s.validateStringLength(
    'clientRequestToken',
    clientRequestToken,
    1,
    64,
  );
  _s.validateStringLength(
    'jobTag',
    jobTag,
    1,
    256,
  );
  final headers = <String, String>{
    'Content-Type': 'application/x-amz-json-1.1',
    'X-Amz-Target': 'RekognitionService.StartFaceDetection'
  };
  final jsonResponse = await _protocol.send(
    method: 'POST',
    requestUri: '/',
    exceptionFnMap: _exceptionFns,
    // TODO queryParams
    headers: headers,
    payload: {
      'Video': video,
      if (clientRequestToken != null)
        'ClientRequestToken': clientRequestToken,
      if (faceAttributes != null) 'FaceAttributes': faceAttributes.toValue(),
      if (jobTag != null) 'JobTag': jobTag,
      if (notificationChannel != null)
        'NotificationChannel': notificationChannel,
    },
  );

  return StartFaceDetectionResponse.fromJson(jsonResponse.body);
}