Source loading as BFF when it's TFF

[rlaphoenix]

Sample: https://mega.nz/file/t9gjxTLY#ILclLeRtd5_NLoJZyqL1e5yjs_TpQMsO9Ym9_mAD0wc

DGIndex, MediaInfo, and MPV all recognize it as TFF,

However, after loading it with core.d2v.Source() in VapourSynth, it loads as BFF,

VapourSynth Script:

clip = core.d2v.Source("mmp_intro_sample.d2v")
clip = core.text.ClipInfo(clip)

--

This is causing Judder when bob deinterlaced as every 2 fields are out of order. It also confuses QTGMC and causes sort of "white luma ghosting" (no color, no outlines).

Judder showcase: https://mega.nz/file/VpgiSTJZ#dDqLpsDibPElEZv7EYn46Y9pGebzsYPiyVvFxxW17FI

The fix for me is to just run SetFieldBased to TFF. However, if a source is not 100.00% interlaced, doing this as a fix would be problematic.
Fix showcase: https://mega.nz/file/Mkw2zC5Y#N6wrjhNbfMAl9RFEkq1-B0dV4nBfCMCiJyUN9KjAg_k

[tvasenin]

Ran into the same issue today -- TFF VOB, MediaInfo correctly detects it as TFF, D2VSource loads it as BFF.

What's especially interesting, DGIndex detects it as TFF during preview, but its D2V Parse feature prints the BFF order!

Could you run D2V Parse over your D2V file?

[tvasenin]

Opened my VOB in VobEdit -- apparently, the video has Interlaced scan type, and the fields appear in the stream as bottom-then-top for every frame, but they are flagged as TFF=0!

Seems as an incorrect stream to me, though I'd like DGIndex to be smart enough to derive field order from the actual state of affairs when it contradicts TFF flag value.