Multiple issues

[Selur]

As per your suggestion:
a. keep deinterlacer at auto - it shows QTGMC (Vapoursynth)
b. make sure the input is detected as interlaced - Input scan type detects Top Field First , so "Overwrite Input Scan type" - left unchecked
c. make sure to select interlaced output in the encoder settings - x264 ->Frames ->Advanced Frame Settings ->Interlaced Encoding checked

that should work,...

-> I'll look into it.

Cu Selur

[Selur]

I can reproduce the issue.
-> I'll work on a workaround, problem is mencoder isn't properly outputting raw interlaced video, this will take a bit.
(man I should have never added support for interlaced output)

Cu Selur

[serg]

I can reproduce the issue.
-> I'll work on a workaround, problem is mencoder isn't properly outputting raw interlaced video, this will take a bit.
(man I should have never added support for interlaced output)

Cu Selur

"man I should have never added support for interlaced output" - this could eliminate portion of potential "Hybrid" users that working with more
advanced material than "home video" (BTW - I believe it's already partially happened because of missing image sequence output option so unloved by you)

[Selur]

How can any video that uses interlaced nowadays be advanced?
Why would you want interlaced video?

Cu Selur

Ps.: as a workaround you could first remux the DVD to an mkv using MakeMKV and feed that mkv to Hybrid.

[Selur]

Okay, this is getting problematic.
1. ffmpeg doesn't support DVD input
2. mencoder doesn't support interlaced raw output
3. both Avisynth and Vapoursynth have none/crappy DVD input support

What I could do:
1. I could force Hybrid to use Avisynth/Vapoursynth to be used when interlaced output is wanted. Problem is with DVD input both always use the first pgc. :/ (no title/chapter support etc.)
2. I could try to first decode with mencoder, then pipe the output to ffmpeg and then to the encoder. (not sure how to tell ffmpeg to interpret raw yuv video as interlaced).
3. I could disable interlaced output for DVD input.
-> looking into it and testing these options

Cu Selur

[serg]

How can any video that uses interlaced nowadays be advanced?
Why would you want interlaced video?

Cu Selur

Well, video editors  use in their programs  different sources, that very often (especially in the documentary) are interlaced .
So, initial timeline usually interlaced in this case. It's more effective (in terms of time consumption) to complete whole project as interlaced and de-interlace
it after finishing, other than de-interlace each shot (that often you need to replace - de-interlace again, ... and so on).

For example: I've got a lot of material captured from BetaSP, 3/4, DigiBeta, DV,DVCPRO, ...etc.
So, following you ideology I have to de-interlace all (well not all, but plenty of them) my video archives (because I don't now yet what exactly piece of videos my Producer will decide to use) before starting the project. The things getting even worse because they( Producers) very often change their mind with the "speed of light" requesting to insert/replace segments by another ones . Of course I'm not going to do that.

[Selur]

Yes, in an ideal world you would make sure your content is progressive and only produce interlaced output if it's needed.
Since:
a. most people think the world isn't interlaced
b. progressive content is way easier to handle
c. H.264 was the last codec that really supported interlaced content (H.265 only has some compared 'ugly' support and for example AV1 doesn't have interlaced support at all)
d. LCD displays are build for progressive content
e. hardware deinterlacers usually aren't that good, so producing interlaced content nowadays is producing a lacking product.

Cu Selur

[serg]

Yes, in an ideal world you would make sure your content is progressive and only produce interlaced output if it's needed.
Since:
a. most people think the world isn't interlaced
b. progressive content is way easier to handle
c. H.264 was the last codec that really supported interlaced content (H.265 only has some compared 'ugly' support and for example AV1 doesn't have interlaced support at all)
d. LCD displays are build for progressive content
e. hardware deinterlacers usually aren't that good, so producing interlaced content nowadays is producing a lacking product.

Cu Selur

"... world isn't interlaced" - I totally agree, however the video world is way far from ideal, an you have to balance between cost of your program and perfection, unless you going to produce way overpriced program in order to follow such philosophy.
Unfortunately the MOST producers I'm working with do not think this way (a.,e) and I'm not going to argue with them.
e. - Terranex so far satisfying the most worldwide video production and broadcast studios.

[Selur]

Doesn't seem there is a way for mencoder to properly output interlaced content via pipe.
Disabling interlaced output when neither Avisynth nor Vapoursynth are used seems to be the only option atm. so you might want to remux your DVD before feeding it to Hybrid.

Cu Selur

[serg]

Not sure about "...properly output interlaced content via pipe".
As I've mentioned before - if I select input as a file (*.VOB) instead of DVD - everything works fine and I do not really understand your "Not really it just look like it" - it looks proper for me.
So, if  *.VOB as file input looks "proper for me", why DVD Input does not?
May be the problem lies not in interlaced stream (that shows properly for me) but in proper DVD structure reading/ interpretation?