Amazon Rekognition
Developer Guide

Starting Streaming Video Analysis

You start analyzing a streaming video by starting an Amazon Rekognition Video stream processor and streaming video into Amazon Rekognition Video. An Amazon Rekognition Video stream processor allows you to start, stop, and manage stream processors. You create a stream processor by calling CreateStreamProcessor. The request parameters include the Amazon Resource Names (ARNs) for the Kinesis video stream, the Kinesis data stream, and the identifier for the collection that's used to recognize faces in the streaming video. It also includes the name that you specify for the stream processor.

You start processing a video by calling the operation. To get status information for a stream processor, call DescribeStreamProcessor. Other operations you can call are StopStreamProcessor to stop a stream processor, and DeleteStreamProcessor to delete a stream processor. To get a list of stream processors in your account, call ListStreamProcessors.

After the stream processor starts running, you stream the video into Amazon Rekognition Video through the Kinesis video stream that you specified in CreateStreamProcessor. Use the Kinesis Video Streams SDK PutMedia operation to deliver video into the Kinesis video stream. For an example, see PutMedia API Example.

For information about how your application can consume Amazon Rekognition Video analysis results, see Reading Streaming Video Analysis Results.

Creating the Amazon Rekognition Video Stream Processor

Before you can analyze a streaming video, you create an Amazon Rekognition Video stream processor (CreateStreamProcessor). The stream processor contains information about the Kinesis data stream and the Kinesis video stream. It also contains the identifier for the collection that contains the faces you want to recognize in the input streaming video. You also specify a name for the stream processor. The following is a JSON example for the CreateStreamProcessor request.

{ "Name": "streamProcessorForCam", "Input": { "KinesisVideoStream": { "Arn": "arn:aws:kinesisvideo:us-east-1:nnnnnnnnnnnn:stream/inputVideo" } }, "Output": { "KinesisDataStream": { "Arn": "arn:aws:kinesis:us-east-1:nnnnnnnnnnnn:stream/outputData" } }, "RoleArn": "arn:aws:iam::nnnnnnnnnnn:role/roleWithKinesisPermission", "Settings": { "FaceSearch": { "CollectionId": "collection-with-100-faces", "FaceMatchThreshold": 85.5 } } }

The following is an example response from CreateStreamProcessor.

{ “StreamProcessorArn”: “arn:aws:rekognition:us-east-1:nnnnnnnnnnnn:streamprocessor/streamProcessorForCam” }

Starting the Amazon Rekognition Video Stream Processor

You start analyzing streaming video by calling StartStreamProcessor with the stream processor name that you specified in CreateStreamProcessor. The following is a JSON example for the StartStreamProcessor request.

{ "Name": "streamProcessorForCam" }

If the stream processor successfully starts, an HTTP 200 response is returned, along with an empty JSON body.

Using Stream Processors

The following example code shows how to call various stream processor operations, such as CreateStreamProcessor and StartStreamProcessor. The example includes a stream processor manager class (StreamManager) that provides methods to call stream processor operations. The starter class (Starter) creates a StreamManager object and calls various operations.

To configure the example:

  1. Set the values of the Starter class member fields to your desired values.

  2. In the Starter class function main, uncomment the desired function call.

Starter Class

//Copyright 2018, Inc. or its affiliates. All Rights Reserved. //PDX-License-Identifier: MIT-0 (For details, see // Starter class. Use to create a StreamManager class // and call stream processor operations. package com.amazonaws.samples; import com.amazonaws.samples.*; public class Starter { public static void main(String[] args) { String streamProcessorName="Stream Processor Name"; String kinesisVideoStreamArn="Kinesis Video Stream Arn"; String kinesisDataStreamArn="Kinesis Data Stream Arn"; String roleArn="Role Arn"; String collectionId="Collection ID"; Float matchThreshold=50F; try { StreamManager sm= new StreamManager(streamProcessorName, kinesisVideoStreamArn, kinesisDataStreamArn, roleArn, collectionId, matchThreshold); //sm.createStreamProcessor(); //sm.startStreamProcessor(); //sm.deleteStreamProcessor(); //sm.deleteStreamProcessor(); //sm.stopStreamProcessor(); //sm.listStreamProcessors(); //sm.describeStreamProcessor(); } catch(Exception e){ System.out.println(e.getMessage()); } } }

StreamManager Class

//Copyright 2018, Inc. or its affiliates. All Rights Reserved. //PDX-License-Identifier: MIT-0 (For details, see // Stream manager class. Provides methods for calling // Stream Processor operations. package com.amazonaws.samples; import; import; import; import; import; import; import; import; import; import; import; import; import; import; import; import; import; import; import; import; import; public class StreamManager { private String streamProcessorName; private String kinesisVideoStreamArn; private String kinesisDataStreamArn; private String roleArn; private String collectionId; private float matchThreshold; private AmazonRekognition rekognitionClient; public StreamManager(String spName, String kvStreamArn, String kdStreamArn, String iamRoleArn, String collId, Float threshold){ streamProcessorName=spName; kinesisVideoStreamArn=kvStreamArn; kinesisDataStreamArn=kdStreamArn; roleArn=iamRoleArn; collectionId=collId; matchThreshold=threshold; rekognitionClient=AmazonRekognitionClientBuilder.defaultClient(); } public void createStreamProcessor() { //Setup input parameters KinesisVideoStream kinesisVideoStream = new KinesisVideoStream().withArn(kinesisVideoStreamArn); StreamProcessorInput streamProcessorInput = new StreamProcessorInput().withKinesisVideoStream(kinesisVideoStream); KinesisDataStream kinesisDataStream = new KinesisDataStream().withArn(kinesisDataStreamArn); StreamProcessorOutput streamProcessorOutput = new StreamProcessorOutput().withKinesisDataStream(kinesisDataStream); FaceSearchSettings faceSearchSettings = new FaceSearchSettings().withCollectionId(collectionId).withFaceMatchThreshold(matchThreshold); StreamProcessorSettings streamProcessorSettings = new StreamProcessorSettings().withFaceSearch(faceSearchSettings); //Create the stream processor CreateStreamProcessorResult createStreamProcessorResult = rekognitionClient.createStreamProcessor( new CreateStreamProcessorRequest().withInput(streamProcessorInput).withOutput(streamProcessorOutput) .withSettings(streamProcessorSettings).withRoleArn(roleArn).withName(streamProcessorName)); //Display result System.out.println("Stream Processor " + streamProcessorName + " created."); System.out.println("StreamProcessorArn - " + createStreamProcessorResult.getStreamProcessorArn()); } public void startStreamProcessor() { StartStreamProcessorResult startStreamProcessorResult = rekognitionClient.startStreamProcessor(new StartStreamProcessorRequest().withName(streamProcessorName)); System.out.println("Stream Processor " + streamProcessorName + " started."); } public void stopStreamProcessor() { StopStreamProcessorResult stopStreamProcessorResult = rekognitionClient.stopStreamProcessor(new StopStreamProcessorRequest().withName(streamProcessorName)); System.out.println("Stream Processor " + streamProcessorName + " stopped."); } public void deleteStreamProcessor() { DeleteStreamProcessorResult deleteStreamProcessorResult = rekognitionClient .deleteStreamProcessor(new DeleteStreamProcessorRequest().withName(streamProcessorName)); System.out.println("Stream Processor " + streamProcessorName + " deleted."); } public void describeStreamProcessor() { DescribeStreamProcessorResult describeStreamProcessorResult = rekognitionClient .describeStreamProcessor(new DescribeStreamProcessorRequest().withName(streamProcessorName)); //Display various stream processor attributes. System.out.println("Arn - " + describeStreamProcessorResult.getStreamProcessorArn()); System.out.println("Input kinesisVideo stream - " + describeStreamProcessorResult.getInput().getKinesisVideoStream().getArn()); System.out.println("Output kinesisData stream - " + describeStreamProcessorResult.getOutput().getKinesisDataStream().getArn()); System.out.println("RoleArn - " + describeStreamProcessorResult.getRoleArn()); System.out.println( "CollectionId - " + describeStreamProcessorResult.getSettings().getFaceSearch().getCollectionId()); System.out.println("Status - " + describeStreamProcessorResult.getStatus()); System.out.println("Status message - " + describeStreamProcessorResult.getStatusMessage()); System.out.println("Creation timestamp - " + describeStreamProcessorResult.getCreationTimestamp()); System.out.println("Last update timestamp - " + describeStreamProcessorResult.getLastUpdateTimestamp()); } public void listStreamProcessors() { ListStreamProcessorsResult listStreamProcessorsResult = rekognitionClient.listStreamProcessors(new ListStreamProcessorsRequest().withMaxResults(100)); //List all stream processors (and state) returned from Rekognition for (StreamProcessor streamProcessor : listStreamProcessorsResult.getStreamProcessors()) { System.out.println("StreamProcessor name - " + streamProcessor.getName()); System.out.println("Status - " + streamProcessor.getStatus()); } } }

Streaming Video into Amazon Rekognition Video

To stream video into Amazon Rekognition Video, you use the Amazon Kinesis Video Streams SDK to create and use a Kinesis video stream. The PutMedia operation writes video data fragments into a Kinesis video stream that Amazon Rekognition Video consumes. Each video data fragment is typically 2–10 seconds in length and contains a self-contained sequence of video frames. Amazon Rekognition Video supports H.264 encoded videos, which can have three types of frames (I, B, and P). For more information, see Inter Frame. The first frame in the fragment must be an I-frame. An I-frame can be decoded independent of any other frame.

As video data arrives into the Kinesis video stream, Kinesis Video Streams assigns a unique number to the fragment. For an example, see PutMedia API Example.