Hello, I'm not a specialist, but I just Solved a similar problem today.
SVP worked fine, and one day, without anychange of me, I have same problems. SVP too low, audio cut out, and slowly pictures.
I tried many solutions: on MPC-HC and SVP filters ... un-instaled , re-instaled SVP and codec, cleaning registry etc...
Ony a new Windows re-installation solved it...
Everything seems ok for two or three days...and again the same problem.
I did not change anything...but I noticed Windows had installed updates..
Today I tried to uninstalled several Windows updates... and SVP function fine again.
I removed five windows update and one windows framework. I'm sorry I forgot to note the first three. But here is the folowing three. KB2748349 KB2749655 KB2779562 the other was near.
For me it was the solution! If it can help you...
sorry for my poor english