Sanitizing video embedding code in Rails. What's a good solution?

What's your preferred method of sanitizing embed code entered in a form? In other words, is there an easy way of ONLY allowing users to embed video from YouTube and Vimeo for example? Do you use the Sanitize helper? If there is a proven solution to this I'd prefer to use it rather than reinventing the wheel. Thank you for r开发者_如何学Pythoneading my question.

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I would give the users custom tags for this, rather than trying to jump through the hoops required to verify embed tags.

For example:

[youtube id=kG16SqUl3bE]

Parse out the ID and generate the embed tag yourself in the view. Safe and easy, and you don't have to allow your users to enter HTML.