Hi there,
so I'm currently trying to restore some older tv shows from 2000ish. I have noticed that nearly all of them were deinterlaced very poorly and I really ask myself who was in charge of this, they just ruined precious content.
I'll provide a sample .mkv and an image for reference. So the whole video has weird lines when people are talking or moving, I'm 100% sure these come from bad deinterlacers used (what on earth did they use, even yadif does a better job??), but sometimes there are some weird artifacts like little dots (as shown in the screenshot, on the guy's face).
Does anyone know what those dots are? I'd say that this is a side effect of the horizontal combing leftovers and after the video got compressed it results in those dots the encoder probably didn't know how to handle properly.
I first ran QTGMC through it and it does a pretty good job eliminating the combing/horizontal lines. However sometimes you can still notice those dots as QTGMC seems to not eliminate them completely. I also noticed that QTGMC denoises pretty heavily, removing some of the digital noise (and I'm one of the very few who actually likes noise as long as it's not distracting and suits the content) which makes the output look way more compressed regardless of the CRF or tuning in x264 used.
I ran it a few times each time adjusting the settings a little bit.
QTGMC(preset="Placebo", InputType=2, sourceMatch=3, sharpness=0.3, tr2=2, ediThreads=8)
probably the best all around solution, combing is gone but occasionally those dots are still visible and digital noise is reduced (which is a con). tr2=1 and sharpness 0.4 helps a little bit retaining the noise but makes those dots more perceptible.
QTGMC(preset="Placebo", InputType=3, sourceMatch=3, sharpness=0.3, tr2=2, ediThreads=8)
Does a better job eliminating those dots but makes the overall image look way softer and degrades the image quality even more.
Is there anything else I could try? I mean I get it, I'm working with a lossy source and obviously I'm gonna lose some details. But I feel like there might be some "experts" in the forum who have more knowledge than I do and I'm looking forward to see what you guys think and how I should handle this source.
Thanks in advance.![]()
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The source was probably telecined film and should have been IVTC'ed (Inverse Telecined i.e. field matched and decimated) rather than deinterlaced.
Try:
Code:tdecimate(cycle=5,cycleR=1) #removes the duplicates qtgmc(inputtype=1) #cleaning up vinverse() #removing residual combing artefacts
Last edited by Sharc; 8th Jul 2021 at 07:11.
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Thanks! I didn't notice the duplicate frames at first, but your script took care of them. I'm not quite sure how this show (Drake & Josh, TV show from 2004) was shot originally but definitely not on film. It's weird because the same episode as provided in the sample is also available as an encode coming from a DVD where the frame rate is also 29.970 but with no duplicate frames (although lower quality). I do not have the original DVD's so I'm not sure but doesn't that mean that most likely the content was 29.970i aka resulting in 59.94p when bob deinterlaced?
I don't know what the studio did when authoring the content because I'm certain the original framerate was not 23.976. Those same dot artifacts also show up on other shows from the 90's (same studio) which were evidently shot on tape, without the obvious combing but with still some leftovers.
Unfortunately those dots are still visible no matter what I do, at this point I think it's impossible to properly filter them out. Also vinverse doesn't seem to do anything, see the screenshot below (it's a different frame than the one above). Only at the bottom of the picture the very small white and blue part of objects are different, rest is the same. Also weirdly enough, just this minor difference is 24KB.
[Attachment 59753 - Click to enlarge]
vinverse on
[Attachment 59755 - Click to enlarge]
vinverse offLast edited by sebastiaaan; 8th Jul 2021 at 08:14.
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The duplicates indicate that the footage was telecined from 24p (or 23.976p) to 29.97i 720x480 at some stage for NTSC DVD compliance (which will be seen on a progressive monitor as a repetitive pattern of 3 clean pictures followed by 2 combed pictures). It was then probably deinterlaced instead of IVTCed, and resized to square pixels 720x540.
You can regenerate the Telecined DVD compliant 29.97i from your .mkv with the hard-telecining script:
Code:TDecimate() # gives 23.976p spline36resize(720,480) #NTSC resolution separatefields() SelectEvery (8, 0,1, 2,3,2, 5,4, 7,6,7) Weave()
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what on earth did they use
Last edited by pm-s; 9th Jul 2021 at 02:59.
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Yeah whoever was responsible for this mess shouldn't be in that position, just messing up old content. It's also weird that those artifacts differ from season to season.
Season 1 for example has the same artifacts but there are no duplicate frames, even at 29.970.
Season 3 on the other hand is 23.976p with no combing except every few seconds but no duplicates. I'll try and make a sample for this as I have no clue how I can tell QTGMC that it should only process those combed frames and leaving the rest untouched.
I'm just a bit confused about your second script you posted though. What would I gain by doing this? Your first script with TDecimate already took care of the dupes. So not sure why I should regenerate the interlaced version or am I missing something? -
It's just an example (or exercise) how the footage with the duplicated frames MAY have been put on the DVD, namely as (hard-)telecined 24fps. Or in case you would need a 29.97i version which causes less judder than the dumb frame duplication. No other purpose than for demo, no solution to the problem. But as you don't have the DVD you can't even compare. Sorry for the confusion.
Last edited by Sharc; 8th Jul 2021 at 13:51.
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This will usually get rid of them, and it will be less destructive than vinverse when it comes to detail retention. It's one of the best filters I know of to clean those leftovers out.
Code:santiag(strv=0, nns=4, nsize=5)
Code:source = last santiag(strv=0, nns=4, nsize=5) MergeLuma(last, source, weight=0.3) MergeChroma(last, source)
If you are going to use QTGMC, this will ensure great quality from it. This is MUCH better than the default settings and a lot less destructive to lines and details. Do not bother with Placebo preset, it's a HUGE waste of time.
Code:QTGMC(preset="slow", matchpreset="slow", matchpreset2="slow", sourcematch=3, InputType=1, tr1=2, tr2=1, NoiseTR=2, sharpness=0.1)
# If you somehow find this a bit more destructive than you would like, take out the sourcematch=3 and see if you prefer that.
You most likely wont need QTGMC if you use Santiag. Santiag is very good at cleaning those combing artifacts. If you can get away with using just Santiag, you will save your video some destruction. If you decide you want to use both, make sure to use Santiag after QTGMC in the script, and not before it.Last edited by killerteengohan; 8th Jul 2021 at 20:39.
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In charge? You're implying this was some sort of a studio effort, which it isn't. Just some incompetent fool at a computer.
I'm not quite sure how this show (Drake & Josh, TV show from 2004) was shot originally but definitely not on film.
I do not have the original DVD's so I'm not sure but doesn't that mean that most likely the content was 29.970i...
I don't know what the studio did when authoring the content...
I'm certain the original framerate was not 23.976. -
I'm not quite sure how this show (Drake & Josh, TV show from 2004) was shot originally but definitely not on film.
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IMDB indicates 1080i for seasons 2 to 4. I suspect it was shot on film in season 1 and broadcast as SD. Then they switched to HD 1080i video for seasons 2 through 4.
https://www.imdb.com/title/tt0363328/technical?ref_=tt_spec_sm
Most TV shows shows were shot on film in those days. The main exceptions were news, soaps, talk shows, and sports. -
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Besides, it could have very well been shot on film in 2004.
I could name a couple of more examples, but take "Scrubs" for example. It was shot on 16mm film all the way from 2001 to the end of the final season in 2010!
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