Nolan Chou

Sometimes we forgot change our file to a available name. So the plugin can help you auto change your upload file. 
I will add a filetype option of setting in next version. 
And a rename popup before the file upload if you change setting in future, default value is post_name.

wp_upload_rename

Change upload filename to random characters / random numbers / date / other by yourself.

Ruslan Mikhno

This is a very simple plugin that allows you to bulk change author for media files.
The action is added in the “List” view of the Media Library.

Bulk Change Media Author

Bulk change author for multiple media files, using the default WP Media Library.

wp_upload_rename vs Bulk Change Media Author