Force redirect from HTTPS to HTTP in Drupal 7 Multitsite?
Maybe you should try and and change the object embed code code to use a protocal-relative URL such as //YOURSITENAME.COM/some/path/to/video/file.mp4 you can do this easily with a WYSIWYG editor or like hook_node_view and regexing for your domain url and an object tag and removing the http:// or https:// as needed ...

Simply google for protocol-relative url and you'll find a bunch of information.