Use Content-Encoding metadata
When you create an object or update its metadata, you can
optionally set the Content-Encoding
metadata. This metadata enables you to indicate that the
object content is compressed without losing the identity of
the underlying media type (Content-Type) of
the file, such as a video.
Content-Encoding header request: HTTP
This example assigns an attachment type to the
Content-Encoding header that
indicates how the file is downloaded: