This demo explains how to upload files to Amazon S3 storage and append additional information about those files as metadata fields - in this case width, height and category.
To upload to Amazon S3, you need to use a special object - AmazonS3Extender. You configure it by specifying AWS-related settings and associate it with the uploader control. When the upload begins, the AmazonS3Extender automatically configures the uploader to send files directly to your AWS account. To append a custom data, you should use the Meta property and specify what data you want to upload.
Note, if you are using the uploader without the ASP.NET Control or PHP Library, you need to do some preparations on the server side (create a policy and a signature).
For better understanding, how the integration with Amazon S3 works, refer Uploading to Amazon S3 with HTML5 Uploader article.
Apps\AmazonS3Metadata folder of the Upload Suite 8 SDK.