[BUG] Interlace Store Method Changing Upon Conversion

[Selur]

I think there might be some confusion here (maybe on my part). The video output that is being generated by Hybrid is still interleaved, not separated yet it is being tagged as separated

Internally mkv always saves interlaced content separated by field (in the container structure) and the actual way the content is saved in the container does differ with the field-order selection on muxing. It's not just a tag.

couldn't the tag just be maintained from the source file and appended to the final tags?

It's not just a tag, also like I wrote I don't know how to tell ffmpeg and mp4box how to tell them to save and signal interlaced contet as interleaved fields.

Alternatively, do you have the your old dev build from April that you had supplied me

ARGH,... do !not! post links I send via PM (edited your post) or I will delete your account.
iirc I changed the way Hybrid handles the muxing of interlaced content to mkv due to changes in mkv since there were some changes a while ago in mkv and this causes Hybrid to not properly save interlaced content.
This is the way it is now and how it will stay unless I would add explicit support for interlaced storage hangling like I sketched out in my previous post, since this is the way that mkvmerge properly saved normal interlaced content.

have 40+ years of analog video sources to archive!

Personally I would bob the content and save it as progressive and not interlaced as more and more newer formats drop support for interlaced content altogether.

Cu Selur