kivy/kivy — pull request #1893 by Zen-CODE (2014-02-16 18:07:07+00:00)
Title: VideoPlayer not responding to source change

If the course is not set on __init__, the video object is never set and therefore does not play video when setting the .source and .state properties later. This can be confirmed via this snippet.

https://gist.github.com/Zen-CODE/9038217

The fix allows the source to be set after initialization,