Field Order changes randomly

[numlock]

I just noticed that some of my captures have wrong field order somwwhere in the middle of the file for about 5-10 seconds. What's the cause of this ? Bad drivers ? Is there any way to fix this ?
I use MSI TV@nywhere and manufacturer supplied drivers

thx

[mustardman]

Had the same problem with a DC30+

The capture was straight from TV (so it wasn't caused by bad signal quality). It turned out that the signal was changing field order at some scene changes. eg: AB AB A A AB AB

Some capture cards can handle this, some can't. I eventually bought one that (I think) does - an ADVC100. Haven't had a problem (yet!).

As far as I know, some TV stations use field based (VCR & VTR) equipment (as opposed to frame based equipment). All the computer stuff I have seen to date is frame based.

If anyone knows of field based computer stuff, please let me know. I am after some!

[jggimi]

Sometimes this happens when movies are "converted" to PAL by adding fields, rather than being sped up. For corrective measures, take a look at the section on Progressive PAL DVDs in our IVTC tutorial (http://www.doom9.org/ivtc-tut.htm#PALTheGoodTheBadAndTheUgly). The link should take you directly to the PAL section.

[jeffoz1]

Had the same problem with my WinTVGo card some time back and I think it may be caused by dropped fields as opposed to frames resulting in the switching of BFF to TFF. I used VdubMod to locate the switching points and a simple Avisynth script to reverse field order at those points. There may be more exotic scripts available to do this automatically.