Deactivate autoplay of video/audio pane

[Leo]

See this thread for a solution:

Is there any way to PREVENT the viewer to AUTOPLAY media?

I can't find a way to prevent the viewer pane to autoplay movies and audio files. The autoplay is useful occasionally, but it can be very annoying, if you double click to open a file in its proper player, and the file starts playing BOTH in the play…