K-Lite pack
That's usually the issue right there. I've heard more than my share of complaints with that K-lite codec pack. Here's just one example:
http://forum.videohelp.com/threads/2442 ... pside-down . Shouldn't really matter if Xlobby launches the video or not, Xlobby (or at least the free version) has nothing to do with video playback. Only the parameters to start the video is passed from xlobby to the video playback software (MPC in this case).
The only codec pack I trust is the one you can download for using with MediaPortal. It is called SAF (I use SAF 4.0, the guy has released a v5). You have to send a "pleading" email to the guy so he will send you the "keys" to install it. Codec packs can lead to alot of headaches. Normally I just use individual codecs. Basically DeScaler's MPEG2 codec for DVD video decoding, AC3Filter for audio, and CoreAVC for HD decoding if I can't get hardware acceleration to work right. Then use ffdshow for realtime filtering of DVD's. I use Zoom Player for DVD video playback. I like how configurable it is. I use MPC for HD playback of mkv files. There I deny ffdshow from being used. It always makes the hd video choppy when I do use it. I then permit CoreAVC to be used. Oh and I should mention that Matroska is also installed.
Back to SAF, I don't really get what that guy does to make it all work, but it's an amazing package. I've tried to set MPC up the exact same as to how that pack configures, I install just the codecs and files listed above, but I always get choppy playback. I install the pack, and all hd content plays smooth. I had that exact issue with my MediaPVR. The on-board video was supposed to be capable of Blu-ray playback, but when I tried to run 1080p mkv files, using the codecs/files listed above, it was choppy. I installed SAF, and 1080p was smooth. So one night I got brave, I noted all the MPC settings he used, all the configurations, the external filters etc. Then I tried to copy what he did...video ran choppy...don't get it, but I went back to just using SAF on that system for MPC HD playback.
Then only thing I have noticed with SAF is that I can't seem to upscale in ffdshow. I like doing that for DVD playback, but for some reason that feature is broken, both with the ffdshow version that is installed with SAF, and also when I tried to install a version separately. But I will make that sacrifice to get smooth hd playback any time.
*EDIT*
On a side note, thanks for the feedback on xStreamed. It helps fuel me to keep on going, knowing people are using it. Any feedback is helpful on improving it. The Pictures module will be release soon. Then most likely an Internet module...finally the beast of a module, the Music module.