/Kretz/blog/

So, there's much interest in the Phonon + Quasar code - as I had hoped

To reproduce the result on your computer you need to get current phonon, current phonon-xine (with libxine >= 1.1.12) and current quasar from SVN. For those that don't know where Quasar lives, you can find it here: http://websvn.kde.org/trunk/playground/base/quasar/. To compile quasar you need to set the KDEDIR environment variable to the prefix where you installed phonon and then run qmake and make in the source dir. Then go to the examples/phonon subdir and run

./phonon /path/to/video.ogg

Have fun detecting edges in your videos ...

I've got it working a long time ago, but since this Akademy it is finally available in KDE trunk: Phonon now can give the raw video frames (as RGB, YV12 or YUY2) to an application and Quasar gained a node to upload those frames as textures and uses Shaders to convert YUV formats to RGB and then do arbitrary effects with them. The cool part about that, obviously, is that the data intensive calculations are happening on the graphics card (you need OpenGL 2 for this to work). To demonstrate the power of this I wrote a simple example that connects the PhononInputNode to an EdgeDetection node and then to a RenderNode. I did a screencapture of the result, but that looks a lot worse than the real performance, which is totally smooth and, of course, doesn't show much CPU usage.

You can also see me adjusting the threshold value of the edge detection filter with a keyboard shortcut.

Here's the code:

Things to note:

• the PhononInputNode is both a Phonon::MediaNode and a Quasar::Node


• the Quasar API is not final, especially wrt. PhononInputNode

As and there will surely be a few more people traveling the same way, I wanted to ask if there's interest in traveling together - or to share a car ride. I've already talked to Martin Gräßlin who lives in Mannheim (I'm in Heidelberg, in case you didn't know already), and we'd probably take a train together. Neither of us owns a car, but if you do and drive by Mannheim/Heidelberg (A5) and want company and people sharing the high fuel cost with you, let me know. If not, you still might want to try to meet up in the train... in that case also let me know.

For the train I'd probably take the ICE 610 (12:35 Mannheim - Köln) and ICE 14 (14:44 Köln - Bruxelles-Nord) on Fr, 8th, of course. But sharing a car ride would probably be cheaper.

Now back to exam preparations...