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# 搜索存储视频中的人脸
您可在集合中搜索与存储视频或流视频中检测到的人脸匹配的人脸。此节介绍搜索存储视频中的人脸。有关搜索流式传输视频中的人脸的信息，请参阅[使用流视频事件](streaming-video.md)。
必须先通过使用 [IndexFaces](https://docs.aws.amazon.com/rekognition/latest/APIReference/API_IndexFaces.html) 将您搜索的人脸索引到集合中。有关更多信息，请参阅 [将人脸添加到集合](add-faces-to-collection-procedure.md)。
Amazon Rekognition Video 人脸搜索将与其他分析 Amazon S3 存储桶中所存储视频的 Amazon Rekognition Video 操作执行相同的异步工作流程。要开始在存储的视频中搜索面孔，请致电[StartFaceSearch](https://docs.aws.amazon.com/rekognition/latest/APIReference/API_StartFaceSearch.html)并提供您要搜索的集合的 ID。Amazon Rekognition Video 会将视频分析的完成状态发布到 Amazon Simple Notification Service (Amazon SNS) 主题。如果视频分析成功，请调用 [GetFaceSearch](https://docs.aws.amazon.com/rekognition/latest/APIReference/API_GeFaceSearch.html) 来获取搜索结果。有关启动视频分析和获取结果的详细信息，请参阅[调用 Amazon Rekognition Video 操作](api-video.md)。
以下过程演示如何在集合中搜索与视频中检测到的人脸匹配的人脸。此过程还演示了如何获取视频中匹配人员的跟踪数据。此过程在[使用 Java 或 Python 分析存储在 Amazon S3 存储桶中的视频 (SDK)](video-analyzing-with-sqs.md)（使用 Amazon Simple Queue Service (Amazon SQS) 队列获取视频分析请求的完成状态）中的代码的基础上进行了扩展。
**在视频中搜索匹配的人脸 (SDK)**
1. [创建集合](create-collection-procedure.md)。
1. [将人脸索引到集合中](add-faces-to-collection-procedure.md)。
1. 执行[使用 Java 或 Python 分析存储在 Amazon S3 存储桶中的视频 (SDK)](video-analyzing-with-sqs.md)。
1. 将以下代码添加到您在步骤 3 中创建的类 `VideoDetect`。
------
#### [ Java ]
```
//Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
//PDX-License-Identifier: MIT-0 (For details, see https://github.com/awsdocs/amazon-rekognition-developer-guide/blob/master/LICENSE-SAMPLECODE.)
//Face collection search in video ==================================================================
private static void StartFaceSearchCollection(String bucket, String video, String collection) throws Exception{
NotificationChannel channel= new NotificationChannel()
.withSNSTopicArn(snsTopicArn)
.withRoleArn(roleArn);
StartFaceSearchRequest req = new StartFaceSearchRequest()
.withCollectionId(collection)
.withVideo(new Video()
.withS3Object(new S3Object()
.withBucket(bucket)
.withName(video)))
.withNotificationChannel(channel);
StartFaceSearchResult startPersonCollectionSearchResult = rek.startFaceSearch(req);
startJobId=startPersonCollectionSearchResult.getJobId();
}
//Face collection search in video ==================================================================
private static void GetFaceSearchCollectionResults() throws Exception{
GetFaceSearchResult faceSearchResult=null;
int maxResults=10;
String paginationToken=null;
do {
if (faceSearchResult !=null){
paginationToken = faceSearchResult.getNextToken();
}
faceSearchResult = rek.getFaceSearch(
new GetFaceSearchRequest()
.withJobId(startJobId)
.withMaxResults(maxResults)
.withNextToken(paginationToken)
.withSortBy(FaceSearchSortBy.TIMESTAMP)
);
VideoMetadata videoMetaData=faceSearchResult.getVideoMetadata();
System.out.println("Format: " + videoMetaData.getFormat());
System.out.println("Codec: " + videoMetaData.getCodec());
System.out.println("Duration: " + videoMetaData.getDurationMillis());
System.out.println("FrameRate: " + videoMetaData.getFrameRate());
System.out.println();
//Show search results
List matches=
faceSearchResult.getPersons();
for (PersonMatch match: matches) {
long milliSeconds=match.getTimestamp();
System.out.print("Timestamp: " + Long.toString(milliSeconds));
System.out.println(" Person number: " + match.getPerson().getIndex());
List faceMatches = match.getFaceMatches();
if (faceMatches != null) {
System.out.println("Matches in collection...");
for (FaceMatch faceMatch: faceMatches){
Face face=faceMatch.getFace();
System.out.println("Face Id: "+ face.getFaceId());
System.out.println("Similarity: " + faceMatch.getSimilarity().toString());
System.out.println();
}
}
System.out.println();
}
System.out.println();
} while (faceSearchResult !=null && faceSearchResult.getNextToken() != null);
}
```
在函数 `main` 中，将以下行:
```
StartLabelDetection(bucket, video);
if (GetSQSMessageSuccess()==true)
GetLabelDetectionResults();
```
替换为:
```
String collection="collection";
StartFaceSearchCollection(bucket, video, collection);
if (GetSQSMessageSuccess()==true)
GetFaceSearchCollectionResults();
```
------
#### [ Java V2 ]
此代码取自 AWS 文档 SDK 示例 GitHub 存储库。请在[此处](https://github.com/awsdocs/aws-doc-sdk-examples/blob/master/javav2/example_code/rekognition/src/main/java/com/example/rekognition/VideoDetectFaces.java)查看完整示例。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.rekognition.RekognitionClient;
import software.amazon.awssdk.services.rekognition.model.*;
import java.util.List;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class VideoDetectFaces {
private static String startJobId = "";
public static void main(String[] args) {
final String usage = """
Usage: