NTSC Vhs to dvd quality

[victoriabears]

I am nearing the end of my 1000 tape project !, and most have been PAL recordings, I am onto the NTSC and am experiencing an aspect that did not occur on PAL, I can call it shimmer, Chroma shift or artifacts, but can only describe it as, it looks like the hair and the face are moving independently of the face, all my vhs recordings are sadly SLP.

I am using a jvc 9911 or Panasonic 1980P VCR, with either an avt8710 or TBC1000 to a jvc M100 DVD recorder, I also have a Pioneer 650H, and JVC M78 dvd combo(Surprisingly good !, but unreliable), some tapes show these symptoms and some not so I suspect it depnds on what vcr I used to record.

Any suggestions how I can cure this ill on the relatively small number of vhs tapes I have left. I can do computer capture using a ads pyro link.

Thanks everyone.

[jagabo]

Sounds like too much temporal noise reduction.

[victoriabears]

What would cuase that as it occurs on the combo as well, so there is no intervening TBC-thanks

[lordsmurf]

I've seen broadcasted NR in years past, especially on indy channels and PBS locals.
Could be part of the source.

The recording VCR could also be at fault. Seen that one, too.

[jagabo]

DVD recorders often have temporal and spacial noise filters.

[lordsmurf]

The M78 doesn't have any NR.

[victoriabears]

Yes I got the sense it was the channel to some extent and it seems almost non existent on the lp recording so it is slp not helping, any solutions?

[jagabo]

Maybe you should post a small sample. But if the problem is too much temporal noise reduction in the source you won't be able to fix it.

[victoriabears]

as requested, annoying they do not look as bad on these clips, may be converting to these formats is the answer !, I used TMPG express by the way. and the dvd recordings were xp on the jvc m78 combo for dawn of the eye and sp on the jvc m100 for the limey.

http://img52.imageshack.us/my.php?image=dawnoftheeye.mp4

http://img215.imageshack.us/my.php?image=limeytest.mp4

The Limey clip looks particularly improved , when playing the dvd his hair raises above his head like a cloud, and concentrate on Brian Stewarts hair in the dawn of the eye clip.

Any help you can give will be great, but again may be converting to divx helps !

[Caple]

I think I have a terrible eye for this kind of problem. Or maybe I'm really used to crappy sources.
I can't see the problems you mentioned

[jagabo]

Yes, what you have is too much temporal noise reduction. Keep in mind that a natural part of MPEG (2 and 4) compression is some temporal noise reduction. So using a higher bitrate may help.

Why does temporal noise reduction introduce this type of artfact? Because noise reduction is essentially a low pass filter. A natural result of low pass filtering is a phase delay. Temporal filters are applied to parts of the frame where the changes from one frame to the next are small. When the changes are very large the filter is not applied, the data from the new frame are passed through right away (otherwise there would be ghosting, or a double exposure look). So the parts of the frames where there are no edges, just continuous small changes in color or intensity (cheeks, forehead), the motions are delayed. In areas where the contrast is high (eyebrows, eyes, mouth) motions are not delayed. Exactly whats in your clips.

Why does this happen in MPEG encoding? Because a large part of MPEG encoding is not including parts of the frame that don't change from frame to frame. When a face moves the motions of those high contrast areas are included in the new frame because the change is large. But when encoding at low bitrates the encoder will think "the color on that cheek didn't change much so I won't include it in the new frame (thereby saving bits, the data from the last frame is displayed again). Eventually, with more motion, the encoder finally decides that the cheek has changed enough that it gets includes it in the new frame. Finally, you see that cheek move, several frames after the eyebrows started moving.

[victoriabears]

Many thanks, I have this on its way

http://www.tigerdirect.ca/applications/searchtools/item-details.asp?EdpNo=3584099&cm_m...SRCCODE=CANLET

and am gonna experiment with computer capture in uncompressed avi, as I have a new computer with a spare hard rive of 750GB, for the troublesome tapes, only some of what I have left is important , others I am not too fussed what it looks like as long as its watchable, but my collection over 23 years has turned up some stuff which has never seen the commercial DVD release, so I want to do my best with it.

The PAL stuff has turned out very well using either a jvc 8965 or panasonic nv 200 pr NV 930 vcr thru avt 8710/tbc 1000 to a jvc m100 dvd recorder, I moved to Canada in 2000 and it is that stuff which is less satisfactory but luckily it is less in quantity.