When an app behaves strangely it is best to close it completely and then relaunch it. From the home screen do the four finger swipe up or double press the home button to reveal your multi task bar. These are all the apps that you have opened at one time. Long press the app until it jiggles and a red minus sign will appear above it. Press the minus sign, this will close the app, not delete it, now press the home button to return to your screen. It's also a good idea to close all these apps, as it helps the iPad run smoothly. Let us know if it is now operating.
The IPad Forum is a community of members from all walks of life and from all over the world coming together to share our experiences and to help each other learn about this wonderful piece of technology the Ipad. There is a wealth of information already here in the many threads we have so doing some searches will answer most of the questions you have. If then you cannot find the answer you are seeking then by all means post your question. There are many friendly and informed members here only too willing to help you.
This happens all the time to me! It's really easy to fix! Here's what you need to do
• find the small black button on the top of your iPad
•hold it down until the line that says slide to turn off comes up
• slide your finger across the line
• your iPad will slowly start shutting off
• a thing in the center will spin when it stops spinning and the screen turns back hold down the black button again until a white apple shows up
• wait until your iPad turns back on, go to your videos, and it should be good as new.