Help deinterlacing a PAL video that wasn't progressive

[GlitchBob]

So for some really absurd reason, Sony managed to release this series on DVD in PAL format (25fps, 720x576) but it's all interlaced. The series was not made that way, so it's quite curious.

In any event, I cannot figure out how to get it properly deinterlaced. My best attempt was with nnedi3, which retains the 25fps, but the deinterlaced frames are a tad jagged and have some "shimmering". Any assistance would be greatly appreciated.

[davexnet]

Sometimes the fields in PAL movies are offset this way,
try

mpeg2source(....)
assumetff()
tfm()

[Sharc]

Yes, it's mostly progressive video which is encoded as interlaced with occasional field shifts. It has probably been done like this for framerate conversion to 25fps.
TFM(mode=1,pp=6) will match the fields and return the progressive frames, and deinterlace only the remaining orphaned fields for which no match is found.
http://avisynth.nl/index.php/TIVTC


Also try

AssumeTFF()
QTGMC(FPSDivisor=2)

Edit:
You may want to compare and optimize the 2 variants like

LWLibavVideoSource("WhySonyWhy.m2v")
assumeTFF()
left=QTGMC(FPSDivisor=2)
right=TFM(mode=1,pp=6,display=true)
stackhorizontal(left,right)

Left is QTGMC, right is TFM:

[davexnet]

"TFM(mode=1,pp=6)"
Thanks for this refinement.

[Sharc]

"TFM(mode=1,pp=6)"
Thanks for this refinement.

It's actually the default AFAIK, so it's the same as TFM(). I just added it so the OP may want to try out other (better) settings.

[Sharc]

Here another proposal using BWDIF with nnedi3:

LWLibavVideoSource("WhySonyWhy.m2v")
BWDIF(field=1,edeint=nnedi3())