How to increase the resolution in a GstAudioVisualizer?

[tagelicht]

Hi,

I am trying to implement an audio visualizer with GStreamer-1.0, specifically using <gst/pbutils/gstaudiovisualizer.h> from plugins-base.
It works just fine as I expected, but the resolution of the GstVideoFrame i get seems to be fixed at 320x200.

Is there any way I can increase that resolution so my visualizer won't look like a bunch of pixels e.g. on fullscreen?