I have got a video not playing in fullscreen. Is it possible to create some kind of mask that I can lay above the black corner? I want the player to see a screen the video is played on.
Currently the engine only supports PlayVideo (http://www.adventuregamestudio.co.uk/manual/PlayVideo.htm)'s options:
Quote0: the video will be played at original size, with AVI audio
1: the video will be stretched to full screen, with appropriate
black borders to maintain its aspect ratio and AVI audio.
10: original size, with game audio continuing (AVI audio muted)
11: stretched to full screen, with game audio continuing (AVI audio muted)
There's a couple of plugins around for embedded Theora video. Check those out and you can play OGG Theora videos the way you want (with a in-game border applied by the engine, as far as I'm understanding you correctly).