You energy is traveling in a linear path. You look more like someone hitting a volley ball smash then a serve. That said it's not bad but the kinetic chain is a broken on a few levels.
Let's start with the bottom:
1) Leg & Hips = You lose all your power from the legs by basically standing up and then serving. Over exaggerate your hip (archer's bow) into the hip and really feel the stretch in your front area and like LeeD said, bend your knees more.
2) Shoulders = don't look too bad. Again I emphasize feeling the stretch that's create by the tilt of your left shoulder over your right. You'll store loads more elastic power.
3) There seems to be something going funky with the pronation of your forehand. You're 'set to launch' position seems off a tad. It's like your forearm doesn't seem to pronate enough. Let me see if I can explain, your racquet should run perpendicular to your shoulders when you enter the back scratcher. As far as I can tell your racquet face doesn't ever go far into the backscratch and your face remains parallel to your shoulders like your driving from elbow like a hammer instead of the arm uncoiling like it should.
The key of not arming the the ball in the serve is to stay lose and use your body's own elastic power to uncoil and drive the 'loose' arm. To make sure you have a loose arm check your grip before you serve. The racquet should feel 'dangly' and rest loosely. You must add a little pressure just prior to contact but that's all.
Hope I helped you.