Maybe elaborate on this a little?

"Get a count of of videos that would be returned by $videoParams when passed to getVideos()"

Also, I think this should be a private or protected method, rather than public.  This function's only parameter is a formatted array of data that is specific to this class.  It would be a little weird to use this outside of  this class (e.g., using a key called 'sort' to tell it whether to count premium or local videos, and a key 'provider' which is never used).