Saving a video through an external camera on android — Flir one

Hi,

I am using Flir one (thermal camera) for my project. I am implementing it in android. All I want to achieve at the moment is that my app should be able to record videos and store it on phone. I have already check a lot of stuff regarding this task on this forum. But everyone has discussed it with respect to internal built in camera. I have never found any post that deals with external camera. Currently I am able to stream frames from the camera and display them on my phone but since I am new to android, I don't know how video recording works? Can anyone provide me a code snippet where I can save the frames to a buffer and write them to a single video file as an output!

Best wishes
Haris