[HELP] Telecine Vatiations Problems, Fixes and Questions...

[shijan]

Let's discuss global problems with various types of Telecine content here and collect all possible fixes in one place!

For start here is some interesting info about Telecine types: http://www.mplayerhq.hu/DOCS/HTML/en/men...ecine.html

I done some tests with some DVDs and here are some reports:

Test DVD 1:
In Progressive mode visible Preview as: 2 frames interlaced, 3 frames progressive
Media Info:
Frame rate: 23.976 (24000/1001) FPS
Scan type: Progressive
Scan order: 2:3 Pulldown
Hybrid auto detects Input scan type as: telecine (soft)

Test DVD 2 (animation):
In Progressive mode visible in Preview as: 2 frames interlaced, 3 frames progressive.
Media Info:
Frame rate: 29.970 (29970/1000) FPS
Original frame rate: 29.970 (30000/1001) FPS
Scan type: Interlaced
Scan order: Top Field First
Hybrid auto detects Input scan type as: "Interlaced", but seems everything back to normal after changing in manually to "telecine (soft)"

In both situations newer "TIVTC" with default "Deinterlacer: inner" and other default settings seems works very well and produce slightly less artifacts with animation than older VIVTC deinterlacer. I didn't notice any problems with "jagged lines" in animation that we discussed earlier here and on doom9 forum in 2020.

----------------

Test DVD 3:
In Progressive mode visible in Preview as: 4 frames interlaced, 1 frame progressive.
Frame rate: 29.970 (29970/1000) FPS
Original frame rate: 29.970 (30000/1001) FPS
Scan type: Interlaced
Scan order: Bottom Field First
Here TIVTC seems detects things incorrectly.

Test DVD 4:
In Progressive mode visible in Preview as: 4 frames progressive, 1 frame repeated progressive.
Frame rate: 29.970 (29970/1000) FPS
Original frame rate: 29.970 (30000/1001) FPS
Scan type: Interlaced
Scan order: Bottom Field First
Same problem. TIVTC seems detects this type incorrectly. It attempt to skip repeated frame but due some unknown reason sometimes it keeps doubled frame and skips another normal frame.
Force Progressive input + sRestore also can't convert it to 23.976 correctly.

Any idea what filter or what settings to use and how to deal with 4 frames interlaced, 1 frame progressive, or 4 frames progressive, 1 frame repeated progressive pattern?

[Selur]

Let's discuss global problems with various types of Telecine content here and collect all possible fixes in one place!

Doesn't make sense without short samples, which:
a. do not cause copyright issues
b. are not too large/long
c. that show horizontal movement

I done some tests with some DVDs and here are some reports:

a. You should look at the content when bobbed, or you should look at the fields when separated. You also need to look at scenes with horizontal movement otherwise you might not see combing artefacts.
b. MediaInfo reports just the output of a few headers, if your source isn't flagged properly nothing it can do.

In both situations newer "TIVTC" with default "Deinterlacer: inner" and other default settings seems works very well and produce slightly less artifacts with animation than older VIVTC deinterlacer. I didn't notice any problems with "jagged lines" in animation that we discussed earlier here and on doom9 forum in 2020.

a. I fixed a bug in how VIVTC was used back in 2020, so old discussions won't help.
b. yes, TIVTC sometimes delivers better results, which is why Hybrid selects it by default on telecine content.
TIVTC will like VIVTC also get 'Fix Telecined Fades' and 'Fix combec with deinterlacer' in some point in time.
Also depending on the source, you might have to run Vinverse/Vinverse2 which are meant to deal with residual combing after telecine.


All the following stuff are just speculations without a source.

• Test DVD 1: sounds like normal telecine, 3:2 pulldown, probably soft telcine
  
• Test DVD 2: sounds like normal telecine, but the source isn't properly flagged
  
• Test DVD 3: sounds like it's not standard telecine.
  Either adjusting the pulldown pattern or Bobbing+sRestore should work.
  
• Test DVD 4: sounds like it's not standard telecine.
  Either adjusting the pulldown pattern or Bobbing+sRestore should work.
  

Cu Selur

[shijan]

Another type of crazy telecined DVD found: 4 frames interlaced, 2 frames progressive.
29.970 (30000/1001) FPS
Scan type: Interlaced
Scan order: Bottom Field First

[Selur]

Does not sound likt it's telecined.
If you want crazy authored dvds simply try to get your hands on some older anime dvd releases, some those were a wild mix of interlaced, progressive, telecined and field shifted content. Especially low budget productions sometimes did horibble things to the content so that no hardware player was able to playback them without some combing here and there.
If you want to see some explainations read https://forum.doom9.org/showthread.php?t=176104 and especially the content linked there.
-> No, there is no way to automatically deal with this kind of stuff properly in Hybrid (without knowing tons of stuff about it and Vapoursynth/Avisynth and writing custom script additions).

Cu Selur

Ps.: also read https://forum.selur.net/thread-1927-post...l#pid12557

[shijan]

That's bad My idea was to collect some most common unusual DVD frame patterns and find some proper "universal" setting in Hybrid for each of them.

[Selur]

LOL,... dream a little dream,.. depending on the input it's a question if you:
a. spend tons of time on analysing the source an write individual scripts
or
b. look for some methods that seems acceptable and doesn't wreck too much
Most problems happened when folks started editing content before making sure everything in their NLE was properly converted to progressive content.
Wildly mixing and cutting cutting different content can really create ugly stuff.

Cu Selur

[shijan]

I can also add another very common type used in DVDs - Progressive content placed inside Interlaced container. This is usually used for 25fps PAL videos.

Container auto detected as interlaced, but if change input type to Progressive video will look like 25fps progressive.

If Change to input interlaced and set QTGMC tff or bff - it will show normal 25 fps framerate. QTGMC will act like noise reduction here. This may slightly improve quality, but same time also may add new strange artifacts.

Changing between tff or bff  usually makes no any difference here because frames are almost the same, but you can experiment and look which version visually look best for you. Same problem - QTGMC may add new strange motion artifacts

If Change to QTGMC bob - it will output 50fps but show two almost identical repeated progressive frames instead of one.

Another probably better way to deal with this footage - instead of QTGMC, set input type to Progressive and use Line -> AntiAliasing -> DAA or DAAmod or Nedi3AA or Santiag filters before Resizer to remove those tiny jagged/interlaced  artifacts.

Frame -> Misc -> Vinverse filter also may help to fix random interlaced combed artifacts, but it also may affect image quality a little.

[Selur]

that's simply wrong flagged content, see: https://forum.selur.net/thread-1927-post...l#pid12747

[shijan]

Reading "Exotic Interlacing(English).pdf" makes me feel very sad. I thought things are not so bad

[Selur]

*gig*