Videos in Heroes of Might and Magic V.

I am interested in the cutscenes at the beginning of the game – the battle with the demon in Heroes V, the battle between dwarves and elves (Magic V - Hammers of Fate), and the siege of a castle by orcs (Magic V - Tribes of the East). If these are scripts, how can I remove the text and menus? Then, I could record them with an HD camera – I wanted to use the video as animated desktop wallpaper.