you need a camera gimble that's stabilized by gyros i think some controllers have them built in
That is one way to do it, but very costly and still not perfect. Unfortunately I am discovering that to get really super smooth perfect video is not gonna happen on a Tri-copter. I love them don't get me wrong, but when I went to a quad the video was way better......and now im moving to a hexa cuz it blows the quad away for stability.
The more motors, the more lifting/stabilizing points around the lifting disc, the more stability.
This is not to say that there is no hope for our beloved Tri-copters, they can get very good video, its just a bit harder. I watched the video, and it didn't appear to have vibrations....which is good...cuz that can be tuff to isolate and get rid of, but getting the "rocking around" out of your footage comes from a few things. If you fly in wind.....you WILL have rocky vids. No matter what. Try to fly in the calmest conditions possible if you are trying to collect smooth footage for a video. Also having your gyro gains set perfectly will help to eliminate rocking. Also your dual rates and expos need to be set at a level comfortable for you. That will help smooth things out a lot. Then finally practice. Which is a never ending journey.
Oh, and one more thing.....I learned through trial and error. Multi-rotors don't fly well light. The lighter it is, the less wind you can fly in and get smooth footage. I was having trouble with a quad that I built cuz i built it super light and it rocked around ALOT so I added weight and wallah it flew rock steady. You just have to figure out the balance between too heavy and too light....too light = rocking around. Too heavy = short flights.
Hope this helps!
Cheers!
Eric