Different settings in deinterlacing on export seem to have no effect on video quality

So basically I have a video which is noticeably interlaced and so I spent the morning exporting the first ten seconds over and over again using different settings. Every result was the same, whether it was progressive or interlaced, bicubic, bilinear, yadif, etc. etc. Each exported video had the same interlacing as the source video. Any ideas?

As I exported the videos, I named them as per what their settings were. None of them looked any different to the others. So the settings I used were:

  1. Interlaced, Bottom Field First, Yadif-temporal+spatial, Hyper Lanczos
  2. Progressive, Bottom Field First, Linear, Bicubic
  3. Interlaced, Top Field First, Yadif-temp, Bilinear
  4. Progressive, Top Field First, Linear, Hyper Lanczos

If you select Interlaced, then there is no deinterlace performed (unless you do something that would cause the vertical resolution of the source to change). Therefore, only numbers 2 and 4 apply. When you select Progressive output, the field order does not matter (it is the field order of interlaced output). Thus, both 2 and 4 are using the same Deinterlacer method because the Interpolation method affects scaling operations and not deinterlace.

Right.

So we’ve established what doesn’t work.

The basic crux of the question, though, was: How do I get a video which is already interlaced to export as deinterlaced, when nothing I’ve tried seems to make any difference?

It just works if you select Progressive in Export. A YADIF deinterlace method is recommended. However, it only works if the clip is detected as interlaced - see Properties. And, you can override it if interlace was not detected.