what app/script is responsible for video media? When podcast videos or youtube videos or flash videos play, what app is behind that?

I'd like to be able to use that script/app to as a trigger for tasker to do something whenever ANY video is playing.

I don't  want to make the apps a trigger because sometimes when apps like YouTube you are just browsing and not watching any video. I want to make a trigger when the media is actually playing.
There isn't a single app or script that runs for all videos. Some video support is built into the Android framework, and each app also have its own logic for playing videos.