I have a JVC-SR9911U attached to a Hauppauge PVR-250MCE. I have used it for a while and have been pretty happy with it, but when playing very noisy VHS tapes I get an unusual amount of macroblocking.

If I capture a clean VHS tape the resulting capture is excellent, with no noticable macroblocking, a tape that is a little noisy I notice some macroblocking if I am really looking but I can live with that, and if the tape is really noisy there can be a lot of little macroblocks all over the screen. The tapes with a lot of macroblocking were recorded off-air, and the reception was poor so the resulting recordings are pretty noisy (sometimes there is horizontal shifting in the picture as well.) The material was also dark to begin with (late night TV talk shows which were dimly lit.) I tried the line TBC on my JVC-SR9911U, it cleans up the picture a very little bit and fixes the horizontal shifting and jitter, but the macroblocking is no better or worse.

I tried using a higher bitrate (as high as 7000-8000 VBR 352x480, I always use VBR, I tried CBR at 12000 but it didn't make a difference either.) Anything over 3500-4500 VBR doesn't seem to make any difference with the macroblocking.

Are there any settings I can adjust with my PVR-250 that I can try to reduce the macroblocking?