AviSynth resizing turns progressive to interlaced BFF??

[Alex_ander]

Never noticed this before but resizing a 100% progressive (reduced from HDTV source) xviD video (AviSynth 2.57, AviSource/AviFileSource) shows 'interlaced BFF' when opening script in TMPGEncXpress 3 (I use it to just test audio/video synch in preview). Disabling resize line (any type - Lanczos, Lanczos4 or Spline36) makes the imported video again shown as 'progressive TFF', same as the original xviD file.
My target is MPEG encoding in CCE and I'd like to know is 'interlaced BFF' a real thing here since my usual CCE template is TFF. The second important thing is: can I still treat the video as progressive for further AviSynth processing (e.g. to use proper framerate conversion scripts etc.)? Thanks.

[Pinstripes23]

encode a small sample using cce by using either line at the end of your script - it encodes 1% of your video throughout.

selectrangeevery(3000,30)

or

selectrangeevery(2400,24)

open .mpv file in vdubmod and see if it is interlaced. I don't preview with any tmpgenc products.

[gadgetguy]

... 'progressive TFF' ...

I wouldn't believe anything that describes your video as this.

[Alex_ander]

Thanks, I've just encoded the whole clip to progressive with no interlacing artifacts. TMPG still treats it as 'interlaced' and DGIndex recognizes it as progressive. Then that's simply the way TMPG analyses imported videos (maybe standard resizing is considered to come from TV source for safety or smth.).