[Kdenlive-devel] Title rotation

[jb]

On Monday 04 January 2010 22:51:56 Till Theato wrote:
> Rotation on all axes adds the possibility to "integrate" a title into
> the video. You can make it look like the text was written on a object in
> the video.
> 
> Might this be worth advancing the syntax of kdenlive titles so it can
> represent rotation?

Hi!

Sure, the kdenlive title syntax must be updated to support new features. 
But you must be aware of one important issue in the design of the titler 
module:

Kdenlive produces xml data, and then, the MLT kdenlivetitle producer (in 
modules/qimage) creates a QGraphicsScene and loads the xml into it. 

The big problem is that using a QGraphicsScene like that in an MLT module is 
not really supported by Qt. 

You are supposed to have a full Qt QApplication to use a QGraphicsScene, but 
when MLT is used inside Kdenlive, we cannot create a new QApplication because 
MLT is running in a thread of Kdenlive. 

So we re-use the QApplication from Kdenlive, but it is in a different thread 
and that leads to some issues, for example using QPixmap crashes the MLT 
kdenlivetitle producer...

so before going too far, I think you should first try to check that the 
features you want to implement work inside the MLT kdenlivetitle producer...

Regards
jb