Do you want to use TinyMCE mediaplugin?

For the last ruby on rails project I used tinyMCE through the great tinymce_hammer plugin (link). 
I needed YouTube support so, after googling it, I decided to use Media plugin for tinyMCE (one in the bundle). 

First

Well, open the file /config/initializers/tinymce_hammer.rb. You need now to extend the "valid elements list" adding this line after the "valid_elements" statement: [:extended_valid_elements, "object[width|height|classid|codebase|data|type],
param[name|value],embed[src|type|width|height|flashvars|wmode]"],

Second

Active the mediaplugin, adding it to:
Tinymce::Hammer.plugins = %w(safari table paste tabfocus codehighlighting media)

Third

adding the button to:
[:theme_advanced_buttons1, 'undo,redo,cut,copy,paste,pastetext,|,bold,italic,strikethrough,|,link,unlink,image,|,media']

Fourth

Save and restart the server

That's all