There is an After Effects for Mac (and Photoshop) plugin I used which does a fairly good job.
Lenscare by Frischluft

For the best result it is still beter to render at twice the end size, apply the filter and scale the end result, because it still is faking. Because of the nature of the depth information, anti-aliasing is not possible (this would suggest matter in between an object in front and the background), I thinkt that is causing the artefacts.
Downsizing hides this. But when the deadline was near I got away without it. This filter is great when you keep it kind of subtle.