Thanks for your answer.
Let me rephrase my request:
I got a framebuffer thats RGBA, but otherwise compliant to the requests
of the pixbuf.
The gdkpixbuf seems to be capable of utilizing RGBA, while the
Gdk::Pixbuf isnt...
Even if i set has_alpha to true, it wont work... in fact, if i do this,
it wont work at all.
So i have to strip the buffer from the alpha channel, but thats quite
expensive and necessary
many times per second since i display various vnc-displays. If i could
access the gdkpixbuf
directly, just place my buffer there and set the corresponding fields, i
could save some
calculations.