Flash is working too slow using QGraphicsWebView

tiftof

I'm also experiencing slow flash in a QGraphicsWebView in QGraphicsView on linux. Is there any progress on performance increase in this situation?

I've been looking into overriding gdk_default_visual as this will also let the flash have transparency, but this seems rather drastic and I have no idea what the influence could be for other item in the qgraphicsview. Has this method been tested yet for increased performance with the opengl backend?

bunjee

Greetings,

I'm also working with a QGraphicsScene + QGraphicsWebView. I'm on Windows Vista + 4.7.2.

I have to say embedded flash is still slower than in the QWebView, see here: http://developer.qt.nokia.com/forums/viewthread/3937/

Any insight on why the flash is slower inside a QGraphicsView ? Any workaround ?

Is the 4.8 likely to improve the situation ?

Update: on OS-X performance seems slightly better.

Thanks.

tiftof

I've submitted a patch to webkit which solves the problem of flashes being slow in a QGraphicsWebView when using opengl: https://bugs.webkit.org/show_bug.cgi?id=66650

bunjee

Awesome tiftof !

Is this going be merged in Qt 4.8 ?

Also it would be interesting to investigate why QGraphicsWebView is slower than QWebView in rendering flash in some configurations.

See here : http://developer.qt.nokia.com/forums/viewthread/3937/

B.A.

tiftof

I have no idea yet :p I don't know if patches for webkit are still in time for Qt 4.8. And more importantly: the patch isn't accepted yet in webkit :)

bunjee

Hey tiftof, any news about your patch ? I'm looking forward to use it myself.

tiftof

Bunjee, I lost track of my patch because I got rid of my performance problems. Because of your reply here, I updated my patch and asked for a review but it got rejected and needs more investigation.

I solved my issue without the patch by forcing the opengl engine to opengl 2 instead of 1: http://doc.qt.nokia.com/latest/qgl.html#setPreferredPaintEngine This solved my performance issue with QGraphicsWebView (see the link to webkit bug report for more info on what was my original performance problem).

With my problem being solved by switching to the opengl 2 engine, I have to be honest that I don't have much time anymore to investigate this problem further. Hopefully you can solve your problem in the same way. If it doesn't and profiling your application doesn't show that every paint of the QGraphicsWebView triggers a QImage::fromPixmap() call to draw a plugin (which causes my bad flash performance), then our problems probably have a different cause anyway.

[EDIT: fixed link, Volker]

bunjee

Hello tiftof !

Thanks for the reply.

According to Qt documentation:

bq. By default, the QPaintEngine::OpenGL2 engine is used

You had to set this flag anyway ?

Thanks.

tiftof

Yes, because I'm using an Intel i915 platform running Linux and Mesa is reporting 1.4 compatibility and not 2.0 because of some missing implementations => Qt will use OpenGl 1 by default on that platform.

qtnext

I have also the same issue in a webview in qml (windows) .. It's far slower than in wekbit (I render my qml in a qglwidget as viewport). Is there any workaround : I have tryed 4.8RC1 but it's the same issue.