Can't load large images in qmlvideofx demo

Opening a large image (e.g. taken with the device camera) to the qmlvideofx demo produces only a black screen. This happens at least on the N8, but not on Nokia 701, which to me suggests running out of graphics memory? A smaller image (e.g. 640*360) opens fine, but at least 4000*2248 seems to be too much.