Black screen means your computer is missing the required Codec to playback the wallpaper properly. Just install K-Lite Codec Pack (any version), and it will install the required codec to playback the wallpaper. After installing K-Lite, change the following Wallpaper Engine setting, Video Framework: to Prefer DirectShow LAV, located under general tab / video.

black screen, like every wallpaper from appletv

I just started using this wallpaper and really like it, but is there any possibility to get it in normal speed?