Need for ForcedField?

[samfchen]

Hello,

I "know" when to use the option of "ForcedField" under Dvd2Avi, according to the guidelines of Doom9's faq's; but, I do not understand WHY is there a need to do so?

Assuming I have an NTSC source at 29.xfps, interlaced, why does one need to use ForcedField so that it will be of a lower frame rate? Is this so that the final encoding will result in a smaller file size due to lower frame rate? Also, I seem to get a lot of "horizontal" scan lines at edges of things moving, is this due to the ForcedField option?

Thank you for the help.
Sam

[phuntyme]

I think you actually NEED to the Force Film option. This should get rid of your horizontal scan line problems

[adam]

Im sure there is a very good description of this on this site but anyways, using force film allows you to encode the film in its original framerate of ~24fps rather than 29.97fps. This means more bitrate per frame and it adds up to about %30 more total bitrate freed up, which theoretically means an increase in quality of about
%30. Also it gives you a progressive source to encode which means there are no interlaced fields, which is what you are seeing when you mention those horizontal scan lines.

[manono]

Yeah-samfchen is a little unclear whether he's seeing the interlacing with just a 30fps .d2v or a 24fps .d2v as well. If you still have the interlacing after using Forced Film, then you have a tough source, and DVD2AVI won't be good enough. You'll have to IVTC using Decomb, GreedyHMA, TMPGEnc., Wizard's IVTC-take your pick.