I have some old EP tapes that I have been capturing and attempting to preserve. Since a lot of the content is originally interlaced video and commercials QTGMC is the obvious first choice.
Unfortunately I am seeing some weird artifacts with one specific area. In testing I have tried multiple captures using different codecs, bypassing TBC, different vcrs, different capture devices...all with the same result. This one little section on the tape gives QTGMC the fits.
The front of the car should look something like this
[Attachment 55302 - Click to enlarge]
QTGMC on its own makes it look like this every other frame, creating some weird flashing errors (trust me it is hard to miss in motion)
[Attachment 55303 - Click to enlarge]
Doubling it up like a repair looks a little better:AssumeTFF()
Don't see the same artifacts with a simple FieldDeinterlace or TDeint but it introduces other less desirable effects:QTGMC(preset="Slower").QTGMC(Preset="Medium", InputType=1)
Trying this lends to some jerky 60fps. Every other frame feels like a halfstep:
This is the best option so far:FieldDeinterlace()
Just curious if anyone has any thoughts on something to try. I feel like I must be missing something with fixing it within QTGMC.tdeint(mode=1)
The entire tape isn't like this. I also have about 12 other tapes with almost 70+ hours in between them so hoping to keep it simple as well.
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If you want to keep it simple, don't deinterlace. It is not needed. Let you TV set do it instead.
Would totally agree if I were doing a final master to DVD for exclusive playback on tv's. Would make my life easier
But I plan on making final versions to h265 mkv with applications like Plex in mind for both tv and PC playback. Plex doesn't always play nice with interlaced material. Any in-software deinterlacing usually pales in comparison to what we can do with avisynth.
I also fear that the further in the future we get (2030, 2040) interlaced support is just going to get dropped from numerous pieces of playback software. Especially as playback for most users slowly moves off of tv's and onto handheld devices and pc's. Plex is half-assing interlaced content support right now, I wouldn't be surprised if in the future they just advise people to re-encode and de-interlace prior to adding to library.
That's not uncommon. The thin horizontal lines can confuse QTGMC and it ends trying to deinterlace something that doesn't need it. This works pretty well on that particular shot:
QTGMC() QTGMC(InputType=2) QTGMC(InputType=2)
That seems to both solve it half the frames and introduce even more bizarre errors the other frames. Or at least it does when I run it through staxrip. So weird.
It would seem that old EP tapes from the 80's and QTGMC might not be best friends.
But using that bit and playing with it some more it looks like I am going to have to stick with a boring de-interlacer up front (tdeint or fielddeinterlace) and then have QTGMC work on it as progressive.
This actually seems to have the best result and is a little quicker
Last edited by jagabo; 6th Oct 2020 at 23:05.
Hmmm. After closing down staxrip, deleting temp files, and re-importing the file my previews all showed good too. Both starting with QTGMC and yadifmod2.
I think I may also be having an issue specifically with staxrip and relying too much on the preview to represent constant changes to a script. After too many changes (30+) and previewing them all, it appears to compound previous lines that have since been deleted. I may have just found a fun bug.