Cannot figure out telecine re-encode.
I have a short film Blu-Ray rip that is 29.97fps MBAFF scan type, pattern 3 progressive frames followed by two combed frames repeating, but I cannot for the life of me figure out what settings to use or alternate tools to utilize to re-encode the film to 23.976 progressive. No matter what frame rate output I try, detelecine on or off, various attempts at deinterlacing, bob or otherwise, etc, and nothing. Always misses frames and the timing and duplicate frames feels inconsistent and wrong. The closest approximation I have is when viewing the original mkv in vlc media player and checking sections frame-by-frame (also how I know re-encode outputs come out wrong) with "Film NTSC (IVTC)" enabled, which seems to do exactly what I want minus the last two frames of the 5 frame pattern being duplicates (which I suspect is a result of the 29.97fps). It does not seem to miss anything or worse the quality of the comb frames or otherwise. Note, though, that I enable it manually as deinterlace detection (off, auto, on) being set to auto does not trigger it. I may be missing key details here, or misunderstanding certain aspects of the original video file, but I have tried searching and digging for inverse telecine solutions and whatnot only to turn up empty. The VLC IVTC deinterlace filter is almost perfect, but part of me still wants to re-encode the file. Does anyone have any insight into this or what could be done with handbrake or other programs? If any additional details are needed from me, feel free to ask. Also, again, I do not doubt that there are some aspects of the situation I am misunderstanding or forgetting about.
EDIT UPDATE: Upon much closer inspection, alongside a mostly successful ffmpeg re-encode, I find that finer details or shadows or other specific parts of even the "progressive" frames (even the ones in the original mkv upon looking cover) also have a fainter combing pattern present, just not as visible and not as blatantly related to frame conversion like with the 2 telecine frames of the group of 5. Now, I don't know what this is or if it could be remedied without worsening the quality.