Re: rate limiting video streaming

APPQoS would be best if your system and license supports it. However you could use a policer to rate video streaming if you know what ports the traffic is using. Here is an example for ftp, you would need to replace protocol ftp with the ports

http://www.juniper.net/techpubs/en_US/junos/topics/example/policer-single-rate-two-color-interface-and-firewall-filter-example.html