Hard to tell much helpful from that angle. I suspect you have a bit too much of your body forward of the bar -Going by how quick your ass comes up and your knees lock; and the appearance that the bar doesn't really touch your leg until half way up your quad.
At 20s you really jerk the bar to get it started -there are good deadlifters who do this and get away with it, but if you're worried about joints and tendons and such I'd quit that.
Here's my coaching tips based on what I think I'm seeing: When you set up really get tight just before you pull -let your arms be relaxed like chains, let your upper shoulders relax but keep that lumbar flat. You're going to take a medium deep breath so that you can keep your upper back in a relaxed position (like not so deep your chest is puffed out). It looked like your ass was in an alright position to start, but it immediately came up when you jerked the bar. So bring that ass down and think about these two things: 1) activate your lats to pull the bar into you. 2) push through your heels.
Before you start the pull -like one second before, lean back take all the slack out of your arms and the bar. You're like a teeter-totter with the weight on one side and your ass on the other -get as much on your side of the teeter-totter as you can. Now think more "push" or maybe "squeeze" than "pull". Sometimes "pull" seems like more back-related. You're definitley going to be using your back, but I think you need to concentrate on putting some of the work on your legs.
You want to get your head behind the bar, but instead of looking up think about pulling your head back making a double chin if that makes sense.
I always suspect that those few biceps tendon injuries from deadlifting are guys that don't train mixed grip and then go to a competition and are suddenly doing maximum pulls in a way they haven't trained*
* I have absolutely no data to back this up