State of the art for awful DVD releases restoration

[cabac]

Hi,
I know it has been discussed a little in the past, but many years have passed and maybe there's something more updated for my use case.
I have bought the first DVD seasons of Family Guy TV show, for digital conservation on my hard drives. They were originally produced for the NTSC distribution (4:3 full frame), they never have been restored, nor re-released in a better format. The only available options in the market are the old DVD releases, NTSC or PAL, from mid 2000's. That's all.

Hence, I have opted for the Region 1 US/Canada releases, hoping for less artifacts caused by framerate conversion. I have found good deals on used markets. Well, as others commented in this forum many many years ago the quality is criminal. I will show here few samples just to let you understand what I am talking about.

My whole point here is that I want to come up with a solution that can be systematic and that doesn't require me watching each episode to clean frame-by-frame (we're talking about more than 100 episodes). I am pretty open to any tool (as long as it can be run on linux). I have a good background in programming and I am familiar with video manipulation (as a teenager I was using Avisynth, so we can go to that level), and I am ready to take a "masterclass" on this topic as long as it can be "set and forget" for all DVDs. At most it can be finetune for each season/release but then I am hoping to massively run encodings.

Side comment. In the library of my home town they have the PAL editions (in case someone could confirm they are better for some reason ).

Where I am now: I have extracted 1:1 copies with MakeMKV for each episode with Engilish audio and subs only. Mediainfo reports the following for the Mpeg2 track

Video
ID                                       : 1
ID in the original source medium         : 224 (0xE0)
Format                                   : MPEG Video
Format version                           : Version 2
Format profile                           : Main@Main
Format settings                          : CustomMatrix / BVOP
Format settings, BVOP                    : Yes
Format settings, Matrix                  : Custom
Format settings, GOP                     : Variable
Codec ID                                 : V_MPEG2
Codec ID/Info                            : MPEG 1 or 2 Video
Duration                                 : 22 min 32 s
Bit rate mode                            : Variable
Bit rate                                 : 5 671 kb/s
Maximum bit rate                         : 9 800 kb/s
Width                                    : 720 pixels
Height                                   : 480 pixels
Display aspect ratio                     : 4:3
Frame rate mode                          : Variable
Frame rate                               : 24.586 FPS
Original frame rate                      : 23.976 (24000/1001) FPS
Standard                                 : Component
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Scan order                               : 2:3 Pulldown
Compression mode                         : Lossy
Bits/(Pixel*Frame)                       : 0.667
Time code of first frame                 : 00:59:58;00
Time code source                         : Group of pictures header
Stream size                              : 914 MiB (97%)
Language                                 : English
Default                                  : No
Forced                                   : No
Color primaries                          : BT.601 NTSC
Transfer characteristics                 : BT.601
Matrix coefficients                      : BT.601
Original source medium                   : DVD-Video

Problem 1: interlaced frames
Frames are supposed to be progressive at 23.976 FPS. It mostly is, but here and there we can see the following:

[Attachment 83109 - Click to enlarge]

Problem 2: jigsaw on oblique lines
This issue is much more frequent. Even with static scenes, it looks like frames were downsampled vertically and then upscaled, producing this "staircase" effect on lines.

[Attachment 83110 - Click to enlarge]

Problem 3: vertically trembling scenes
This is related to the previous problem. It seems that consecutive frames have been kind of shifted vertically, producing this annoying shaking effect (see `cut.mkv`).

Now... I have started to play a bit with Vapoursynth, looking for filters, but of course there's an ocean of options. I am hoping that someone is more updated to the new standard for old problems, or maybe someone has simply encoded these exact material. Any hint/recommendation/pointer is welcome!

[aramkolt]

The streaming quality isn't any better than the NTSC DVD? That would already be progressive and most likely be from the original progressive source material and at a higher bitrate than DVD.

If you do want to go the DVD route, PAL would have more vertical lines of resolution and if the frame rate is 25 or less, you wouldn't be giving up frame rate either, but I can't really comment on whether the quality is any better than NTSC.

There's likely some component of inverse telecine that should be done to get it back to whatever the original frame rate was, but there's an interesting thread here about it that shows different methods with different results:
https://forum.doom9.org/showthread.php?t=175825#:~:text=When%20IVTC%20was%20applied%20...2019.181%20FPS.

[cabac]

The streaming quality isn't any better than the NTSC DVD? That would already be progressive and most likely be from the original progressive source material and at a higher bitrate than DVD.

That's true. Unfortunately, I couldn't find any way get those, not even _illegally_. Moreover, I think to remember that streaming editions (which honestly I haven't watched) are censored in some parts (which is a pity for that kind of show).

[cabac]

This video frame I think is really informative. Notice how the "staircase effect" only affects characters and furniture but not the overlay test (notice the "y" in particular, its oblique line is fine).

[Attachment 83115 - Click to enlarge]

[Selur]

just clicking stuff together,... https://pastebin.com/TUc2Lkim

[cabac]

That's impressive!

[Selur]

To be frank it's 'ugly' it doesn't really fix the problem properly, it basically brute forces some stability. (even using BasicVSR++)
Adding additional steps (with SMDegrain&Co) one could probably make it even more 'stable', but processing will get really slow.
It probably would be better to do some decimation (maybe multiple) using some pull-down patterns, but I'm too lazy for that and wanted to see how far I come with some 'brutal' filter chain.
It's kind of a shame, that something like this got released as a DVD. Seems like quality control wasn't really a priority. ¯\_(ツ)_/¯

Cu Selur

[cabac]

I see the point. If I find the time I will try to collect all the libraries you used in the chain and give it a try. I am curious to see the impact on clean frames or other frames which suffer of other issues.

In the meanwhile I had the chance to put my eyes on ripped versions from streaming services (only for season 1, which on DVD seems to be the worst).
- The resolution is somehow higher (even though I had read that episode were produced at NTSC standard for the first 9 seasons).
- The bitrate is much higher (this is clear even in the opening theme which is very dynamic)
- Interlacing much less frequent (but still present)
- The staircase effect is still there
- The trembling is still there.

What a criminal gang...