2013-03-23, 17:09
Not terribly hard to do - just a little custom XML file to allow a persistent PiP window when XBMC isn't in fullscreen video mode and a few changes to the includes.xml and Home.xml skin files. Those changed behaviour to reflect a new boolean called "Skin.HasSetting(Player_Show_PiP)", which can be toggled by the added option in the skin settings menu.
Drawback: PiP window obscures certain text that might need to be read (Z-order of window is 2 so it sits on top of all other dialogs).
Solution: Conditional visibility is set to hide the PiP window when player is paused.
Drawback: Jerkiness of PiP when moving between certain skin elements.
Solution: Unknown - this always seems to be a problem with the "videowindow" dialog.
Drawback: "black-back.png" background to letterbox/pillarbox content with aspect ratio other than 16:9 is visible if a video is started when no video was previously playing (just before going fullscreen a black box pops up).
Solution: Unknown - looked into visibility tags in the XBMC wiki but found no definitive solution. Considered getting rid of the background and stretching all content to fill the 16:9 PiP window but a) I don't like aspect ratio warping on content and b) the "videowindow" dialog supports basic default window tags only.
Minor drawbacks aside, this fixed a few major ones specific to my setup (video playing in background on skin windows which didn't have a "videowindow" dialog in the bottom left would skip and stutter the audio, visualization on Home screen looked awful due to a rendering area error) and allows you to keep a watchable video running while doing other things in the skin, for example building a playlist or letting the credits of one episode run while choosing another.
Works well in conjunction with a few of my other mods, the reduced size Bookmarks OSD and persistent "content info taskbar":
