I found an amazingly simple solution
After spending most of the day restoring factory settings and even bloody downloading a new app and a hundred other things none of which worked I simply used the search facility for one of my films and it played straight away and I could see my library. I tried playing the rogue episode which crashed it in the first place it went black again did the search thing again and all was right with the world of ipad once more
Use the iPod app to fix it!
Start the iPod app and play a podcast. If you don't have any, just download one through the app and play it. Once done, try playing a video. This worked for me!
Quick, simple and no resetting/rebooting/deleting/reloading!