Summary:

This modal window will play HTML5 videos at a maximum height and width based on browser window dimensions. The videos will always fit within the window while maintaining it's correct aspect ratio, also removing the black bars that can occur on the top, bottom and sides.

Notes:

YouTube tends to encode all their 2.35:1 videos within a 16x9 Container. This will force encode black bars on the top and bottom of the video. Therefore using the 16x9 container is recommended.