moviepy.video.fx.all.fadein

moviepy.video.fx.all.fadein(clip, duration, initial_color=None)

Makes the clip progressively appear from some color (black by default), over duration seconds at the beginning of the clip. Can be used for masks too, where the initial color must be a number between 0 and 1. For cross-fading (progressive appearance or disappearance of a clip over another clip, see composition.crossfade