2016-05-04, 10:28 (This post was last modified: 2016-05-04, 10:30 by emale.)
Your question is nearly two years old and your use case is a bit different from mine but I had the same question and still wasn't able to find an answer for that.
I'm not sure if my handicraft work with snippets from different sources was the best solution but it works. The main facts are:
I created a service-addon
With xbmc.Player().isPlayingVideo() I was able to detect if video is playing or not
xbmcgui.ControlImage(x, y, w, h, pathToImage, aspectRatio) in combination with xbmcgui.Window(windowid) and the correct windowid for video (12005) adds an image to your video
xbmcgui.ControlLabel(x, y, w, h, text, font, textColor, alignment) adds a textbox to your video
To detect the correct time to display the musicvideo info labels you could use the current video position xbmc.getInfoLabel('Player.Time("hh:mm : ss")') and the video duration xbmc.getInfoLabel('Player.Duration("hh:mm : ss")')