The angle makes it hard to tell, but it looks like you're sliding forward in the bottom. Try to get your knees in position much earlier (1/3 of the way down). That should help you stay tighter on the descent and out of the hole.
On the DL, you're moving the bar an awful lot before you start your pull. Try to not move the bar at all prior to pulling, making sure that it's about 1 inch away from your shins. Once you bring your shins to the bar, you have to really think about squeezing your chest up, until you feel like your head is going to explode. This will help you set your back and maintain lumbar extension.
Hope that helps!