I've been struggling with "video stutter" issues ever since I built my SageTV-based Home Theater PC. Some shows would play back fine, others would be slightly jerky, and still others seemed to have intermittent "frame skips". After installing a new HD receiver, the problem worsened. Read on to see how I resolved the issue, and how I now enjoy excellent quality SD and HD video with SageTV....
I've tried lots of combinations of settings, and even purchased nVIDIA's PureVideo decoder. This improved things, but I still was plagued with video stutter problems. Then, I added HD to the mix, and HD video became unplayable. I don't know what possessed me, but I went into SageTV's setup screens and began playing with all of the "video renderer" and "video decoder" combinations. After some trial-and-error, I found that choosing the "VMR9" renderer and the "InterVideo" decoder produced excellent, stutter-free video on both HD and SD recordings.
I do notice an occasional minor "frame skip" in some Star Trek: Voyager & TNG shows, but the overall playback quality is vastly improved . Now, I'm not complaining.
Your experiences may certainly vary depending on your hardware setup. There are many factors that can affect video playback. What worked for me may or may not work for you.
This new configuration completely removes PureVideo from mix reducing the complexity of the setup. I'm going to do some more investigation as to why the INterVideo decoder out-performs everything else, but for now, I'm going to just stop tweaking and enjoy the show, leaving the WAF* at a nice high level.
*WAF=Wife Acceptance Factor