All connection packages with the real ROV will create a video topic that can be used.
Also, if you want to grab it without ROS, take a look in the video class.
Im trying your example called gazebo teleop (GitHub - patrickelectric/bluerov_ros_playground: Scripts to help BlueRov integration with ROS) and having some trouble.
`roslaunch bluerov_ros_playground gazebo_teleop.launch
… logging to /home/tilgaard/.ros/log/1d4987c2-294f-11e9-8eb6-0c8bfd0e4a5c/roslaunch-dell-16588.log
Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.