I was wondering if there's am option hidden away somewhere (that I can't seem to find) for prioritising the amount of CPU resources made available to KRR.
I also have Mezzmo running on my PC and that plays a movie really smoothly when transcoding an incompatible audio file, whereas KRR, though it does play it too, has a lot of stop/start/buffering!
The reason for this I think might be, is that I have Mezzmo's transcoding set to highest CPU priority, whereas I don't see the option available in KRR.
There is no such option in KooRaRoo, because what I found is that if you set your CPU to highest, the server may not have enough CPU slices left to actually stream. Such settings are typically best not exposed, as they may not be really helping, but may instead be causing other problems.
If transcoding is not smooth, then perhaps an incorrect device profile is used, or the profile can be optimized further. Can you please tell me the make and model of your DLNA device? If we need to optimize/modify the profile, then please open a ticket through support and I'll be happy to look into this.