[Qt-interest] Quicktime C -> QImage

["Alexander Carôt"]

... I just figured the following:

CFDataRef data = CGDataProviderCopyData(CGImageGetDataProvider(image));
rawData = (unsigned char*) CFDataGetBytePtr(data);

gives me the raw pixels from a CGImageRef. I already succeeded in displaying my first captured Quicktime-Video-Frames on a QImage. Still some color issues and so forth. I will verfiy and possibly get back later.

Thanks for your initial comments, which helped a lot.
Best

-- A l e x



-------- Original-Nachricht --------
> Datum: Mon, 19 Apr 2010 11:00:01 +0200
> Von: "Alexander Carôt" <alexander_carot at gmx.net>
> An: Stephen Chu <stephen at ju-ju.com>
> CC: qt-interest at trolltech.com
> Betreff: Re: [Qt-interest] Quicktime C -> QImage

> Hi Stephen,
> 
> thanks a lot for the swift response !
> 
> > That is a CoreGraphics image reference. How do you actually get a 
> > QuickTime image?
> 
> I believe this is my actual problem (I am newbie to OSX graphic (esp.
> Quicktime) programming). How do I obtain the pixel array or pointer to the
> pixel image data ? Once I have this I will load it straight into the QImage
> buffer as you described below.
> 
> Thanks a lot in advance
> 
> -- A l e x
> 
> 
>  
> > > and then I thought about using the QImage::setPixel(...) in this way:
> > > 
> > > 
> > > ************
> > >     unsigned int *pixels = (unsigned int *) image;
> > >     int i = 0;
> > >     for (int y = 0; y < 240; y++){
> > >       for (int x = 0; x < 320; x++){
> > >         displayImage->setPixel(x,y,pixels[i]);
> > >         i++;
> > >       }   
> > >     }   
> > > **************
> > 
> > If the "image" variable is the same one you get from CGImageCreate, it's
> > just a reference, not a pointer to image buffer. I am surprised it 
> > doesn't crash.
> > 
> > setPixel is too slow for image construction. You need to create a QImage
> > from the external buffer you get from QT or other source: 
> > http://qt.nokia.com/doc/4.6/qimage.html#QImage-6
> > 
> > Or you can load the QT image directly into a QImage's owned buffer:
> > http://qt.nokia.com/doc/4.6/qimage.html#bits
> > 
> > HTH.
> > _______________________________________________
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> > Qt-interest at trolltech.com
> > http://lists.trolltech.com/mailman/listinfo/qt-interest
> 
> -- 
> http://www.carot.de
> http://www.triologue.de
> Email : Alexander at Carot.de
> Tel.: +49 (0)177 5719797
> 
> 
> 
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-- 
http://www.carot.de
http://www.triologue.de
Email : Alexander at Carot.de
Tel.: +49 (0)177 5719797



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