You can upload videos to an Object Storage Service (OSS) bucket and use the video snapshot feature to extract video thumbnails, keyframes, or specific frames from the videos.
Usage notes
When you capture snapshots from videos, you are charged based on the number of captured snapshots. For more information, see Data processing fees.
OSS can capture snapshots from videos only in the H.264 and H.265 formats.
By default, OSS does not automatically store captured snapshots. You need to manually download captured snapshots to your local storage devices.
Parameters
Category: video
Action: snapshot
Parameter | Description | Valid value |
t | The point in time at which you want to capture the snapshot. If the value exceeds the length of the video, the last frame is returned. Note If you want to capture a video thumbnail, set t to 0. | [0, video duration] Unit: milliseconds |
w | The width of the snapshot to capture. If this parameter is set to 0, the width of the captured snapshot is calculated based on the proportion of the height of the captured snapshot to the video height. | [0, video width] Unit: pixel |
h | The height of the snapshot to capture. If this parameter is set to 0, the height of the captured snapshot is calculated based on the proportion of the width of the captured snapshot to the video width. If both w and h are set to 0, the snapshot width and height are the same as the video width and height. | [0, video height] Unit: pixel |
m | The mode used to capture the snapshot. If this parameter is not specified, the snapshot is captured in the default mode. In other words, the snapshot at the specified point in time of the video is captured. If this parameter is set to fast, the most recent keyframe before the specified point in time is captured. | fast |
f | The format of the snapshot to return. | jpg and png |
ar | The mode that you want to use to automatically rotate the captured snapshot. |
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Examples
This section provides examples on how to capture snapshots from a video that is stored in the oss-console-img-demo-cn-hangzhou bucket in the China (Hangzhou) region. The video is hosted at the following URL:
https://oss-console-img-demo-cn-hangzhou.oss-cn-hangzhou.aliyuncs.com/video.mp4
Use the fast mode to capture the snapshot at the 7th second of the video. Export the captured snapshot as a JPG image whose width is 800 pixels and height is 600 pixels.
The URL used to apply the preceding parameters is https://oss-console-img-demo-cn-hangzhou.oss-cn-hangzhou.aliyuncs.com/video.mp4?x-oss-process=video/snapshot,t_7000,f_jpg,w_800,h_600,m_fast.
Capture the snapshot right at the 17th second of the video. Export the captured snapshot as a JPG image whose width is 800 pixels and height is 600 pixels.
The URL used to apply the preceding parameters is https://oss-console-img-demo-cn-hangzhou.oss-cn-hangzhou.aliyuncs.com/video.mp4?x-oss-process=video/snapshot,t_17000,f_jpg,w_800,h_600.
Generate a signed URL to capture a video snapshot
You can use OSS SDKs to generate a signed URL to capture a video snapshot. The following sample code provides an example on how to use OSS SDK for Java to generate a signed URL to capture a video snapshot:
// In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint.
String endpoint = "http://oss-cn-hangzhou.aliyuncs.com";
// We recommend that you do not save access credentials in the project code. Otherwise, access credentials may be leaked. As a result, the security of all resources in your account is compromised. In this example, access credentials are obtained from environment variables. Before you run the sample code, make sure that the environment variables are configured.
EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
// Specify the name of the bucket in which the video object is stored. Example: examplebucket.
String bucketName = "examplebucket";
// Specify the full path of the video object. If the video object is not stored in the root directory of the bucket, you must provide the full path of the object. Example: examplefolder/videotest.mp4.
String objectName = "examplefolder/videotest.mp4";
// Create an OSSClient instance.
OSS ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider);
// Capture the snapshot right at the 17th second of the video. Export the captured snapshot as a JPG image whose width is 800 pixels and height is 600 pixels.
String style = "video/snapshot,t_17000,f_jpg,w_800,h_600";
// Set the validity period of the URL to 10 minutes.
Date expiration = new Date(new Date().getTime() + 1000 * 60 * 10 );
GeneratePresignedUrlRequest req = new GeneratePresignedUrlRequest(bucketName, objectName, HttpMethod.GET);
req.setExpiration(expiration);
req.setProcess(style);
URL signedUrl = ossClient.generatePresignedUrl(req);
System.out.println(signedUrl);
// Shut down the OSSClient instance.
ossClient.shutdown();The method used to generate signed URLs to capture video snapshots is similar to that used to generate signed URLs to process images by using Image Processing (IMG). To use the following OSS SDKs to generate a signed URL to capture a video snapshot, replace the IMG operations in the code with the snapshot operation.
FAQ
Can I process a video object whose ACL is private by directly adding parameters to the URL of the object?
No, you cannot. If the ACL of the video object that you want to process is private, you can use OSS SDKs to add video processing operations to the signed URL of the object. You cannot process a video object whose ACL is private by directly adding parameters to the object URL.
How do I check the width and height of a video object that is stored in OSS?
You can use the video information extraction feature to obtain the width and height of a video.
Why is a captured video snapshot distorted?
The video from which you capture the snapshot uses the BT.2020 color gamut. The video snapshot feature does not support videos that use the BT.2020 color gamut.