Deinterlacing VHS capture

[InterloperUX]

Hey there,

As this is my first post, I'll just let you know that I *have* searched the forums for info beforehand.. I know people tend to just jump in and ask a question sometimes. I've been using videohelp as a resource for ages now, but this is the first time I've needed to really ask for advice that hasn't been answered elsewhere.

My issue:
I'm restoring a VHS capture from a 90s live video release by my favourite band. I was looking for some advice on deinterlacing. The source is noisy, but I'm taking care of that with Neat Video - There is a lot of fast-moving camera work, quick cuts, some sections with strobe lights, and video effects (e.g. intentional ghosting of movement, a lot of scenes where footage from two cameras has been overlaid together into one shot). I've read about and installed NNEDI3 + Yadifmod. Reading through the instructions, I'm a bit concerned, though. My understanding is that, my options are to either select the top or bottom field and let the filter interpolate (or guess, right?) what the other half of the picture is. Or I can get it to do both fields, one after the other, interpolate the missing field and have a 50fps video. Either way, it sounds like a dramatic reduction in resolution. Do I have any other options or does anyone have any suggestions, given the specifics of the source? I'm a bit of a perfectionist - I figure if I'm putting time into making this capture look awesome, it'd be nice to have the best result possible.

[poisondeathray]

If you want "best" possible results, use QTGMC for the bob deinterlacer , or leave it interlaced

[InterloperUX]

Cheers, I'll check it out I forgot to mention - the source is NTSC433 (or PAL60, right?)

[poisondeathray]

Cheers, I'll check it out I forgot to mention - the source is NTSC433 (or PAL60, right?)

I don't know what you mean by those designations? NTSC433 ? PAL60 ?

A PAL recording in the UK or Australia should be 50 fields per second, 25 frames per second

[sanlyn]

Agreed, QTGMC is the only way to go. But save your original interlaced capture. Reason: once you deinterlace and destroy your original, it's gone forever. Deinterlace technology will improve with time, but if your original capture is gone you won't be able to take advantage of improvements.

I don't usually deinterlace VHS captures, but I use QTGMC and several other plugins to repair the bad interlace artifacts that almost always result from VHS playback problems. QTGMC also does some denoising and chroma cleanup as well, and the results can be re-interlaced for encoding to DVD. This would be a decent starting point:

AssumeTFF().QTGMC(preset="medium")

To re-interlace for original playback frame rate:

SeparateFields().SelectEvery(4,03).Weave()

For progressive playback without doubling the frame rate:

SelectEven()
# ----- or use SelectOdd() if you think Odd frames look better ----

After QTGMC you'll find you can use lower-power settings with NeatVideo.

Usually, DVD for NTSC and PAL are interlaced for DVD disc. Progressive playback is usually for PC and internet.

[Richard_G]

It all depends what you are going to do with the capture, as said, if you intend putting it on DVD leave it interlaced as that is what DVD should be. If you are going to turn it into something for the web then it will need to be de-interlaced.

I've not come across NTSC433 but PAL60 is what you get if you play an NTSC video and output it to a PAL display (such as playing a US DVD on a multi-standard player and displaying it on a PAL TV). It's converted into PAL but at 30fps (60 fields per second).

[InterloperUX]

It all depends what you are going to do with the capture, as said, if you intend putting it on DVD leave it interlaced as that is what DVD should be. If you are going to turn it into something for the web then it will need to be de-interlaced.

I've not come across NTSC433 but PAL60 is what you get if you play an NTSC video and output it to a PAL display (such as playing a US DVD on a multi-standard player and displaying it on a PAL TV). It's converted into PAL but at 30fps (60 fields per second).

Thanks for clearing that up for me. I thought it was PAL60 but my EasyCap would only capture it under an "NTSC433" mode and NOT PAL60, for whatever reason.

I'm thinking of keeping a progressive, digital copy AND a DVD at this point.

I don't usually deinterlace VHS captures, but I use QTGMC and several other plugins to repair the bad interlace artifacts that almost always result from VHS playback problems. QTGMC also does some denoising and chroma cleanup as well, and the results can be re-interlaced for encoding to DVD.

Thanks for the tips! Would you mind going into some detail on how you repair interlacing artifacts? (And if I understand right, QTGMC can be used to make these repairs without deinterlacing? Or is that always part of the process?)

[sanlyn]

I don't usually deinterlace VHS captures, but I use QTGMC and several other plugins to repair the bad interlace artifacts that almost always result from VHS playback problems. QTGMC also does some denoising and chroma cleanup as well, and the results can be re-interlaced for encoding to DVD.

Thanks for the tips! Would you mind going into some detail on how you repair interlacing artifacts? (And if I understand right, QTGMC can be used to make these repairs without deinterlacing? Or is that always part of the process?)

The basic operation of QTGMC is deinterlacing. It does so using motion interpolation along with denoising and repairing of various interlace artifacts (such as mild anti-aliasing, etc.). It has several modes, which are presets that vary the strength of its processing. QTGMC downloads with html documentation. But there's a lot of info in the avs script itself -- QTGMC is an avs script, not a plugin.

It seems somewhat intimidating, but that's why the preset modes are handy; they set the icky parameters for optimized performance. Slower modes = more power. The default preset is "slow", which is sloooowww and often overkill that can leave video looking a little raw. The code snatches posted earlier can handle many problems.

QTGMC requires several plugins and support files. This support stuff is used by many other Avisynth filters, so having them around is a good deal for other tasks. The current Doom9 post has download links for QTGMC itself and for a package of all its support files. There's also a link for use with MT processing -- don't even get involved with MT at this point, it's a hassle, so ignore that link. The doom9 post is here: http://forum.doom9.org/showthread.php?p=1423459#post1423459

There's the matter of the format you've used for capture. Is it AVI ? MPEG ? QTGMC works in YV12 and, with a special version of a couple of support plugins, in YUY2. At the outset don't try to get too complicated; the settings suggested should be a revelation. Some detail about your capture format would be helpful.

[InterloperUX]

There's the matter of the format you've used for capture. Is it AVI ? MPEG ? QTGMC works in YV12 and, with a special version of a couple of support plugins, in YUY2. At the outset don't try to get too complicated; the settings suggested should be a revelation. Some detail about your capture format would be helpful.

I've been playing with it for a while just now and think I've figured out some settings that suit my needs I already dove in to setting up the MT version, lol. If you're interested, these are the settings I've chosen:

SetMTMode(3, 4)
AssumeTFF().QTGMC(Preset="medium", EdiThreads=1, EZKeepGrain=1.0, SourceMatch=2, Lossless=1)

Depending on the encoding time, I might shift that to "slow".

I'm not actually sure on the capture format. I used Lagarith, which I believe converts input to RGB, by default. I'm not sure if I left that on..
*Actually, I just noticed the Video Color Depth setting in Virtualdub (which I captured in,) which appears to convert and pass RGB, by default, to the compressor, so whatever it was in, it would be in RGB now.

[Cornucopia]

Here we go again with F@#$ing Easycap! I've heard more problems involving easycap in the last month than all other products in the last year combined. Get something that doesn't force you into a crappy encode/format to begin with.

Scott

[Richard_G]

I bought one but never managed to get it to work! I only wanted to use it to connect a CCTV cam to a pc.......

[sanlyn]

(agreed, @Cornucopia. But we don't know the full story yet....)

That capture info doesn't tell us that much. If you captured to RGB, things are a bit haywire from the start. VHS is usually captured to AVI with lossless Lagarith or Huffyuv in YUY2, not to RGB. But if you did cap to RGB, then to run QTGMC you need to start:

ConvertToYV12(interlaced=true)
SetMTMode(3, 4) 
AssumeTFF().QTGMC(Preset="medium", EdiThreads=1, EZKeepGrain=1.0, SourceMatch=2, Lossless=1)
...[ some other processing here ]...
SeparateFields().SelectEvery(4,0,3).Weave()
# --- for VirtualDub work -----
ConvertToRGB32(matrix="Rec601",interlaced=true)

[jagabo]

I'm not actually sure on the capture format. I used Lagarith, which I believe converts input to RGB, by default. I'm not sure if I left that on..
*Actually, I just noticed the Video Color Depth setting in Virtualdub (which I captured in,) which appears to convert and pass RGB, by default, to the compressor, so whatever it was in, it would be in RGB now.

Set VirtualDub to capture as YUY2. Set VirtualDub's color depth to Auto. Set Lagarith to YUY2 mode.

[InterloperUX]

Here we go again with F@#$ing Easycap! I've heard more problems involving easycap in the last month than all other products in the last year combined. Get something that doesn't force you into a crappy encode/format to begin with.

Scott

To be fair, while I had trouble getting a "genuine" EasyCap that supported PAL60, its really irrelevant to this discussion - either way, I'd be dealing with an interlaced VHS source.

I bought one but never managed to get it to work! I only wanted to use it to connect a CCTV cam to a pc.......

If you still want to try, the advice and drivers on http://easycapexpertti.mybisi.com/ solved a lot of problems for me. (Along with some older posts on this forum...)

(agreed, @Cornucopia. But we don't know the full story yet....)

That capture info doesn't tell us that much. If you captured to RGB, things are a bit haywire from the start. VHS is usually captured to AVI with lossless Lagarith or Huffyuv in YUY2, not to RGB. But if you did cap to RGB, then to run QTGMC you need to start:

ConvertToYV12(interlaced=true)
SetMTMode(3, 4) 
AssumeTFF().QTGMC(Preset="medium", EdiThreads=1, EZKeepGrain=1.0, SourceMatch=2, Lossless=1)
...[ some other processing here ]...
SeparateFields().SelectEvery(4,0,3).Weave()
# --- for VirtualDub work -----
ConvertToRGB32(matrix="Rec601",interlaced=true)

I just tested capturing and the source was YUY2. And I just learnt about AviSource().info, so I can confirm its still in YUY2, and BFF. (So yeah, I'll have to change that AssumeTFF..) Are configuring those additional supporting plugins for YUY2 worth the hassle, or should I just convert to YV12? It seems more ubiquitous..

EDIT: Okay, so maybe its not BFF, I just learned the reasoning behind the AssumeTFF..

[sanlyn]

BFF -- Yes, Avisynth always assumes BFF. VHS is almost always TFF, but you can test it with:

AssumeTFF().SeparateFields()

View the video one frame at a time in VirtualDub. If horizontal or vertical motion jerks back and forth, the field order is BFF. If motion looks correct, it's TFF.

[jagabo]

BFF -- Yes, Avisynth always assumes BFF. VHS is almost always TFF, but you can test it with:

VHS is neither TFF nor BFF. It's an alternating sequence of top and bottom fields. It's the capture device (or its drivers) that determines whether the frames are TFF or BFF.

[Cornucopia]

Yes, and the frame ordering could be adjusted in AVISynth (losslessly) to swap from one to the other (or vice-versa) if necessary, regardless.

Scott

[sanlyn]

@jagabo, I haven't found a VHS tape or capture in my system that wasn't TFF since my first capture in 1999. But I'm certain one will come along eventually. Maybe PAL country is different. But I know what you're saying. The first step I take -- almost always -- is the SeparateFields() bit.

[jagabo]

I haven't found a VHS tape... that wasn't TFF since my first capture in 1999.

VHS is an alternating sequence of top and bottom fields. It has no frames so it can't be TFF or BFF. It's only when the video is captured in a digital form that pairs of fields are woven together into frames, creating a field order.

Capture a VHS tape with your regular capture device (which apparently captures TFF) and then with a DV camcorder (or Canopus ADVC DV capture device). That one tape will give you both a TFF and a BFF file. Both will play normally. It's the capture device that creates and determines the field order.

[sanlyn]

Yes, I knew what you were saying. I didn't state it correctly, but your explanation is more precise. TFF/BFF is in the capture chain, not in the tape itself.

[InterloperUX]

Thanks again, I appreciate all of the help. Hopefully this thread will be useful to others that are new to this.
While I'm here, I'm just thinking about other filters to further improve the (perceived) quality of the final product. I've seen deblocking filters mentioned before in relation to VHS captures, but I don't understand the purpose, with an analog source. I mean, blocking artefacts come from compression, right? There shouldn't be any compression artefacts to negate from a lossless capture of an analog source. Any ideas on why they'd be recommended?

[jagabo]

I've seen deblocking filters mentioned before in relation to VHS captures, but I don't understand the purpose, with an analog source. I mean, blocking artefacts come from compression, right? There shouldn't be any compression artefacts to negate from a lossless capture of an analog source. Any ideas on why they'd be recommended?

You are correct, VHS has no blocky artifacts. But some people capture with hardware MPEG or MJPEG compression devices. They end up with blocky captures that can use deblocking. If you are capturing with a lossless codec you don't need deblocking (unless the VHS recording was made from a blocky source).

I don't know what you're using to play the tapes, but quality caps from VHS start way before the capture device. The best quality will come from an S-VHS deck with a line time base corrector. A full frame time base corrector will help keep A/V sync during tape dropouts. If you can't afford an S-VHS deck consider using a set-top DVD record that has both line and full frame TBCs that work in pass-through mode.

https://forum.videohelp.com/threads/232830-Test-of-various-VCRs-Image-Quality-from-VHS-...%28Big-Pics%29
https://forum.videohelp.com/threads/306272-Computer-video-capture-vs-vcr-to-dvd-combo?p...=1#post1882662
https://forum.videohelp.com/threads/319420-Who-uses-a-DVD-recorder-as-a-line-TBC-and-wh...=1#post1983288

[InterloperUX]

I just read quite a lot about them, and I'm feeling good about a Panasonic AG1980P: http://www.ebay.com.au/itm/Panasonic-AG1980P-VHS-Player-Recorder-Editor-/390537768564

Really wondering whether to blow that much money, though... Though I'm sure that if it works well, it shouldn't be hard to resell it, if its as valued in the... video restoration community as it appears to be.

Edit: I only have a laptop, so afaik my only option as far as the capture device is the EasyCap. Really not keen on blowing money on a new desktop just to get a capture card. Does that make the whole TBC thing superfluous? Funnelling from a top of the line VHS deck into a capture device that cost me $15, in other words.

[jagabo]

EasyCap should be fine for VHS. As long as you don't see obvious problems when capturing with your current VHS player.

[InterloperUX]

Hey there,

So rather than starting a new thread, I thought I'd continue with this one, since there's already a lot of information here about what I'm doing. My Panasonic 1980P arrived today, and I just finished capturing the video from it. There's one issue, that may be codec-related, though:

These colour bands show up throughout the captured video:


I went back and checked a few sections and still frames from live capture in Virtualdub, and they don't appear to be present in the feed directly from the VCR, only after encoding. I thought it might have been a tracking problem. I've had a look around for info on chroma artefacts, but I couldn't see anything relevant. Just to refresh: I'm using Lagarith, S-Video + 2 x RCAs to a "real" easycap, from a used Panasonic 1980P. Any help would be very much appreciated.

[InterloperUX]

Straight from the source: (It does seem to be fairly noisy here, but most of the tape looks great.)


P.S. Hadn't noticed this issue with my consumer player, only the 1980P.

It becomes very noticeable in some brighter sections of the video.

[jagabo]

Just to be sure we're talking about the same thing, you're talking about these diagonal bars (accentuated here), right?



That's usually caused by a ground loop -- noise by some device in the chain leaking through the cabling (or internal to a device).

http://www.youtube.com/watch?v=4YM1iwC6vhg

He's talking about audio but the description of the problem is applicable. Make sure you have proper grounding. Plug all devices into the same power strip. Etc.

[InterloperUX]

I'm thinking its probably having the transformer I bought to power the VCR sitting right next to the VCR and my laptop :P Or perhaps these expensive cables were a rip-off.. I'll try a few things tomorrow. Thanks.

[InterloperUX]

I thought I'd solved it by wrapping some foil around some of the cabling, setting the transformer across the room, and plugging the laptop and vcr into a powerboard =/ Came back 30 minutes into the capture and saw the same artefact showing through very obviously. Looks like I'll buy a roll of foil and wrap the entirety of the cable, AND the easycap..

A brother-in-law suggested clip-on magnets for the cabling. I don't suppose you'd know anything about these or their suitability for the application? I'm not finding anything relevant on google.

[jagabo]

Foil wrapped around the cable will only stop external noise from entering the cable. It won't stop noise traveling down the cable.

The clip-on magnet is also called a "ferrite bead". It's used to remove high frequency noise. I don't think it will work in your case but it's worth a try.

http://en.wikipedia.org/wiki/Ferrite_bead

Also try different s-video cables. Price (Monster) is no guaranty of quality with cables.