Well, I'd say that 3 years ago or now, concrete5 can certainly do it. It's just a question whether it's the best possible platform for that purpose.

It sounds like the site would be much more about user generated content than editor/admin managed content, so I'm not sure whether concrete5 would be the best fit for that purpose. While we've also build some community sites with concrete5, there is always the question whether that is the most viable option.

Does your site have a lot of COTENT MANAGEMENT needs? If yes, probably concrete5 is a very good tool for building your site.

If not, I would certainly weigh the options since I think concrete5 best excels at its content management possibilities, while it also gives you SOMETHING to use with for the communities (e.g. user profiles, avatars, etc.).

And back to the original question: I don't think there are any suitable add-ons that would get you that kind of site for under $500, so if that is what you're looking for, the answer is "no", concrete5 cannot do that. But concrete5 can still do a lot and it can do even more with custom coding. If you're willing to spend thousands of $s for custom development (at least), then the answer is "yes", concrete5 can certainly do that.

I'm also not sure about the scale of your site but video streaming is by no means easy or cheap to do. If you're building a large scale site, there's a lot to think about that might affect the big picture. By no means, I would suggest building the video streaming functionality on top of concrete5. I think there are much better tools for that available.

If you're looking for a low budget solution that can scale easily over time, I would certainly suggest you to host the videos e.g. in YouTube, Vimeo or Dailymotion. The latter two even provide business-level accounts that allow you to host your own videos safely. And I would assume they also provide some kind of API that allows you to manage the video uploading / fetching automatically, without the need of asking your users to go into those services to upload the videos.

I'm not and our company is not associated with those companies in any way but I'm just saying, use them (or something similar) if you want to save a lot of money and keep a lot of headaches our of your calendar. Then, just build the front-end on top of concrete5, if you believe that's the best fit for the front-end experience.