Understanding visual artifacts in animation DVD

[CrispyJogging]

I could use some help understanding the nature of some visual artifacts I'm seeing. I spent the better part of yesterday researching interlacing and telecine-ing and while I have a general sense of the two I'm not certain exactly what I'm dealing with.

The source is a personal rip from the first disc of a Complete Collection of a popular animated series from some years back. Disc was backed up using MakeMKV's Backup feature, the resultant ISO was unzipped to a folder, and the VOB file played via mpv.

The artifacts I'm referring to appear to be frames with interlaced images overlaid onto a progressive frame.


[Attachment 82060 - Click to enlarge]

The predominant pattern seems to be 4 progressive frames followed by 1 interlaced frame (PPPPI) most of the time, but not always. From what I've read, I'm guessing the footage has been telecined to convert from 24 fps (typical animation frame rate) to 29.97 (NTSC broadcast frame rate).

What confuses me is that these fifth frames appear to be progressive when I view it in mpv, with the interlaced image seemingly baked in? I thought an interlaced frame would only display half of the image but maybe mpv is overlaying it onto the previous frame and merging the two? Or did the manufacturer render a shoddy encode that is fully progressive but with interlaced artifacts on every fifth frame?

Trying to resolve these unsightly frames, I've tried both detelecine and deinterlace in Handbrake. Starting with the default Fast 1080p30 preset, I set Cropping to None, Resolution Limit to 480p NTSC SD, Constant Framerate to 23.976, Constant Quality 18.

With Detelecine only, the interlaced images are gone but there's residual ghosts of the interlacing:


[Attachment 82061 - Click to enlarge]

With Decomb only, the ghosts are more pronounced:


[Attachment 82062 - Click to enlarge]

With both Detelecine and Decomb, I cannot detect any ghosting but there are perhaps duplicate frames now:


[Attachment 82063 - Click to enlarge]

What I'd like to know is how best to resolve artifacts like this. I know my way around Handbrake but if learning Avisynth and using TIVTC is going to yield superior results, I'm willing to learn. I'd also appreciate if someone could clearly diagnose just what these artifacts are -- just so I understand whether to mentally note them as interlacing or telecine (or maybe just a shoddy encoding job by the manufacturer?).

I've attached a sample clip in case anyone would like to step through the footage themselves. I tried to create it as losslessly as possible and didn't perform any cropping or transcoding that I'm aware of. Generals steps were:

• Trim from original VOB using LosslessCut
• Demux m2v using rejig

Thanks in advance for any guidance you can offer.

[Selur]

Using TIVTC (and adjusting the parameters, seems fine)

clip = core.tivtc.TFM(clip=clip, mode=6, chroma=True)
clip = core.tivtc.TDecimate(clip=clip, mode=7, rate=23.9760, dupThresh=0.04, vidThresh=3.50, sceneThresh=15.00, chroma=False)# new fps: 23.976

One could remove the duplicates if ending up at, 12000/1001 fps is okay.

24 fps (typical animation frame rate)

23.976 would be typical progressive NTSC content.
Typical cartoon / animation seems to me more like 8, 12000/1001, 12, having real 23.976 or 24 fps cartoon seems rather uncommon to me.
(for computer generated stuff 23.976 might be a common NTSC frame rate, but for typical cartoon I would say: No)

Cu Selur

Ps.:just a few examples TIVTC.mp4 = just TIVTC with the above settings, cleaned.mp4 = TIVTC + mclean + BasicVSR++, mclean.mp4 = TIVTC + mclean + santiag, dgdenoise.mp4 = TIVTC + dgdenoise + santiag, there are tons of filtersmodels to upscale (conventional and machine learning based) cartoon content.

[SaurusX]

This is ‘90s animation so I’m sure there are plenty of videotape edits in there to screw up the telecine pattern. These afternoon shows varied wildly in terms of their production with many studios being used for a single series. The Japanese stuff is going to probably be much more consistent, but not entirely. Sometimes 12 unique frames per second, but sometimes it will indeed be 24(23.976). You never know.

But I agree with Selur. Use TIVTC as it’s the best field matching tool out there.

[CrispyJogging]

Based on reading Dealing with Aspect Ratios, it sounds like this is a case of "hard telecine" which, as mentioned, can be corrected by application TIVTC.

Thanks all for the information, clarification, and the samples of corrected footage. Time to break out AviSynth and get to work.