Reencoding degrades my video. Please help!

[royrose]

I capture my analog Hi8 video using a Panasonic HS2 DVD recorder. The capture quality is superb but the HS2 only makes simple menus. I copied the VOB files into my computer, demuxed them and reauthored to make better menus.

My problem is that when I do this, the resulting video is bad with a ratchetting/stuttering quality when there is motion, especially panning. The original HS2 captured video is perfectly smooth. I get this effect whether I use arcsoft/MyDVD software that came with my SONY DRU-500A drive or DVD complete by Dazzle. I also got this effect using video captured by a dazzle capture device. If I play the reauthored DVD on my computer, it looks good by when I play it on my TV with my stand alone DVD player, I get the jitter.

Does anyone else have this problem? Any ideas what the cause is or how I can fix it?

Roy

[jdobbs]

Probably field order. When you reauthor and reencode try reversing your settings (TFF).

[royrose]

Thanks for the lead. Trouble is, I don't know what field order or(TFF)is. Can you explain what that is and how to set it. Thanks.

Roy

[jdobbs]

I'm not familiar with your encoder, but typically there is a way to set field order. When a video is played back, it is actually displayed by in two parts, even lines and odd lines -- it goes way back in the first TV days and is related to the persistance of phospher on the screen. A long story...

Anyway, when displaying you have a choice as to the order in which each of the two sets of lines (fields) is displayed. They are called even/odd or top and bottom. There is a flag in MPEG-2 that tells the playback machine which field should go on the screen first. It is called TFF for Top Field First. It is set to 0 or 1.

You have to make sure the flag matches the originally recorded field order.

The reason it doesn't show on your computer is because the computer doesn't really do even/odd scanning. But your TV does. When they are reversed (backwards) the result is the jittering you're seeing. (taking a leap of faith that this is really your problem).

If your software doesn't have the ability to fix it, there are other ways (like using a utility called "PULLDOWN.EXE") -- there's a lot of articles in this forum on this subject. Use the search engine and look for "TFF"

[royrose]

Thanks again. I did find other areas where this is being discussed. It gives me hope that I can fix it.

Roy