If your source URLs for S3 materials include region information, the platform will use region data from the source URL to infer the region to process jobs within.
For example, if https://bucket.s3-us-west-1.amazonaws.com/path/to/sourceis specified, we will use the us-west-1 (US - Northern California) region.

A few things to note about this feature:

Automatic region select is overridden if you specify a parameter in your request.
If you're using Reserved Cloud Instances automatic region select will not be used. We will process media in the region of your Reserved Instances.
If you specified multiple sources we will use the region from the first Amazon S3 source. In case that first source isn't S3 we will process your media in default region.

<?xml version="1.0"?>
<query>
    <userid>[UserID]</userid>
    <userkey>[UserKey]</userkey>
    <action>[Action]</action>
    <source>[S3SourceFile1]</source>
    <source>[SourceFile2]</source>
    <!-- Multiple sources -->
    <source>[SourceFileN]</source>
</query>

{
    "query": {
        "userid": "[UserID]",
        "userkey": "[UserKey]",
        "action": "[Action]",
        "mediaid": "[MediaID]",
        "source": [
            "[S3SourceFile1]",
            "[SourceFile2]",
            "[SourceFileN]"
        ]
    }
}