Get your nipples pointed at the ground sooner. You look like you're trying to keep your chest up the whole time.
You're really never getting your knees to stay put and they're traveling the whole time. You can see them punch forward at the bottom. Get them out front sooner (1/2 to 1/3 of the way down) and keep them there. This will also cause you to have to control the descent a bit so you don't let them smash forward. Try a TUBOW (or foam roller on its end) and see if that helps.