Please test the rcd_speedup_new branch in librtprocess
A while ago, the original author of RCD (Luis Sanz Rodriguez), Hanno Schwalm and I collaborated to make a simpler and faster implementation of RCD.
This version is available in the librtprocess rcd_speedup_new branch https://github.com/CarVac/librtprocess/tree/rcd_speedup_new
Edit: The new RCD code is already used in RawTherapee for a while without complains. Though it's not really tested with astro shots.
Edited by Ingo Weyrich