Removing artifacts/stuttering from mixed progressive/telecined source

[blotto37]

Description of problem or question:

Using source from a DVD that has mixed progressive and telecined frames (NTSC film -> video). I have tried using Interlace detection with Decomb and yadif with same as source and vfr. Have not been able to remove all artifacts and stuttering.


Steps to reproduce the problem (If Applicable):




HandBrake version (e.g., 1.0.0):

1.3.3


Operating system and version (e.g., Ubuntu 16.04 LTS, macOS 10.13 High Sierra, Windows 10 Creators Update):

macOS 10.13.6


HandBrake Activity Log ***required*** (see How-to get an activity log)

https://pastebin.com/embed_js/FuJHAbLP

[Woodstock]

First recommendation would be to disable comb detect (force removing interlacing of all frames). For me, this helps with interlaced sources.

The film->video/video->film changes aren't that it is kicking in and out of interlaced, it's that the frame rate is changing. It's still interlaced video.

[blotto37]

Huh, I thought it was hard telecine since the combing isn't notable throughout. I'll give your recommendation a try.

[blotto37]

I ran two tests on one of the most difficult scenes: test 1 w/ Yadif default setting and test 2 w/ Decomb EEDI2. Interlace detection off. Test 2 does slightly better at reducing combing artifacts but at a price in speed: 4.253632 vs 16.820484 fps average encoding speed for Yadif. Still not perfect but acceptable.

Would I gain anything using the ‘Bob’ setting? What speed setting would be appropriate, given the changing frame rate? I understand that you should only enable this if the video really has two fields per frame.

[Woodstock]

Those are questions beyond my direct knowledge.

I have been using Bob for my deinterlace work. Haven't tried the others.

[Lostless]

Have you tried detelecine? If the source is a film, it may just work without a deinterlace meathod and avoid some deinterlacing artifacts.

[blotto37]

Given that the playback framerate is 29.97 frame/s, my inclination was that this was indeed a hard-telecined DVD. I tried detelecine initially, however I was not satisfied with the result. And deinterlacing unconditionally resulted in more artifacts. Stepping though high motion scenes, I see a 3-2 pattern of progressive-interlaced. The best output I have achieved is when I transcode without any filters and let VLC deinterlace. Using interlace detection's fast setting with default decomb looks promising, with almost indiscernible artifacts. I'll try EEDI2 next and finally default yadif. My idea with using the fast setting is to only apply deinterlace on visible interlaced frames.

[blotto37]

"Fast" Interlace Detection w/ default Decomb yields the most pleasing results. However one scene in particular, looking at these test samples, seems to be caused by deinterlacing. Any thoughts on how to correct?

Decomb

Yadif

Deinterlace Off

[Woodstock]

That scene has horizontal lines in the scale buildings that will cause issues with the detection. They look too much like the combing effect of a bad interlace.

[blotto37]

Interlace Detection settings:

"Less Sensitive"

Code: Select all

mode=3:spatial-metric=2:motion-thresh=3:spatial-thresh=3:filter-mode=2:block-thresh=40:block-width=16:block-height=16

"Fast"

Code: Select all

mode=0:spatial-metric=2:motion-thresh=2:spatial-thresh=3:filter-mode=1:block-thresh=80:block-width=16:block-height=1

Less sensitive properly ignores that scene however it leaves far too many artifacts, whereas the fast setting has few artifacts but also tries to deinterlace the scale buildings. If I understood the syntax might I apply a custom setting that would handle both?

[blotto37]

Source, according to mediainfo:

Code: Select all

Video
ID                                       : 224 (0xE0)
Format                                   : MPEG Video
Format version                           : Version 2
Format profile                           : Main@Main
Format settings                          : BVOP
Format settings, BVOP                    : Yes
Format settings, Matrix                  : Default
Format settings, GOP                     : M=3, N=12
Bit rate mode                            : Variable
Maximum bit rate                         : 7 500 kb/s
Width                                    : 720 pixels
Height                                   : 480 pixels
Display aspect ratio                     : 4:3
Frame rate                               : 23.976 (24000/1001) FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Scan order                               : 2:3 Pulldown
Compression mode                         : Lossy
Time code of first frame                 : 02:46:40:17
Time code source                         : Group of pictures header
GOP, Open/Closed                         : Open

[blotto37]

An mp4 transcode in VLC w/ deinterlace on resulted in a frame rate of 24.4 fps. How would I set this up in Handbrake? I had audio sync issues when I used 23.976 constant frame rate w/ detelecine on.

[mduell]

Enable deinterlace and leave it variable (peak) framerate.

[blotto37]

I used a matroska preset with ac3 audio passthrough and variable frame rate, same as source. Audio syncing is spot-on and combing is almost indiscernible. Compare the log below with the original mp4 transcode above.

https://pastebin.com/embed_js/RS9XvEcA