The "rights of privacy and publicity" involved here will depend on your state law.
Generally, you can film or photograph a crowd without getting everyone's permission, but there are important caveats and exceptions.
To begin, there usually is no protection for information (e.g., photographs, videotapes) that either is a matter of public record or was disclosed and gathered in a public place. In other words, filming a crowd is usually OK and you don't need permission from everyone in the crowd.
One exception may be when someone is the focal point or center of attention of the film or photo. In your case, that might be the BB players, which raises another important issue: minors. Typically, you need parental permission to broadcast images of a minor. Your attorney, after reviewing your film and facts, can best advise whether permission is needed from the minor BB player's parents, though I think not.
Also, you should determine if the school is considered a "public place" (probably), and it wouldn't hurt to check with the school to make sure they don't have a policy prohibiting filming of students. Getting permission never hurts.
You should also check youtube's policy: http://www.google.com/privacy.html
Lastly, you should know that internet laws are in a state of turmoil. Although many courts and commentators view the internet as a public forum, once your film hits youtube, it's free for anyone in the world to see and use, which may raise other issues beyond the scope of this general forum.
In sum, your filming and posting of a public basketball game is probably OK, but you should make sure there's no twist in your state law or the school's policy that would prohibit the posting.