Although some of the following pre-requisites may already be in place, you will need a document library and a web part page.
Step 1: Create a Document Library to contain the Web Part Pages (aspx). These files must have a home, but you can use an existing library if a suitable one exists. The name of the library is somewhat arbitrary, but should be as consise as possible. It is also a good idea to provide an accurate description of the library.
Step 2: Create the Web Part Page or modify an existing page that will contain the video content.
Step 3: Edit the newly created Web Part Page and add a ‘Content Editor Web Part’.
Step 4: Enter the Embed code (either manually or by cut-and-pasting from YouTube, etc) into the source editor of the CEWP.
Step 5: Exit from editing mode of the Web Part Page and you should now see a video player with your video.
Step 6: If you are using a publishing site, with corresponding web content management enabled, the steps are slightly different, just add the CEWP and Embed code. Don’t forget to check-in and publish your changes.