File name of saving video shouldn't contain special chars

[wafcio]

The biggest problem is with / which create new folders. Some filesystem even don't allow to have : or some other special chars.

I think it will be good to change title with slugify method and use this value as filename.

[smcabrera]

Yeah that makes sense.

[smcabrera]

I just encountered an example of this bug we can test against, it's a talk from rubyconf2015

Downloading it will, as you rightly point out, create a nested folder structure instead of just creating the file.