Author Topic: Converting Videotape to Digital  (Read 1497 times)

Sebastian Cobb

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Converting Videotape to Digital
« on: January 15, 2021, 10:40:00 PM »
I was going to make this before the Cassette thread, honest!

I've got a film I'd been wanting to get for ages, the only copy I could find was a VHS promo copy sent to video hire places as a sample - the barcode has 'SAMPLE' stamped through it.

I've managed to get an alright machine for the transfer - a Panasonic NV-HV61, a fairly fancy machine in its day by the looks of it. I couldn't justify an SVHS machine to transfer standard VHS even if they are marginally better at even standard VHS.

I also have a spare tape so will play around that first and give the transport a clean with some isopropyl alcohol.

My plan is to capture as losslessly as I can, then smash the thing through a topaz upscaler on a rented EC2 instance, to try and upscale it. Then encode into something with a decent codec.

My main question is how much should I worry about the capture device? A mate said it doesn't matter much with modern chips, I have a cheap one coming from aliexpress and will vet it, but are there any better ones that won't break the bank?

I understand it shouldn't matter too much as I will be capturing composite anyway, using S-Video can apparently make capture worse because a lot of VCR's pull some half-arsed conversion to S-Video from composite anyway.

The film in question is this: https://www.imdb.com/title/tt0215108/

Malcy

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Re: Converting Videotape to Digital
« Reply #1 on: January 15, 2021, 11:16:37 PM »
This was my next thread! Something I’ve been wanting to do for ages as I still have a load of VHS that I can’t bring myself to throw out until I at least know what is on them and I’m sure I’ve got good stuff on them.

notjosh

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Re: Converting Videotape to Digital
« Reply #2 on: January 16, 2021, 08:09:44 AM »
I've been wanting to do this for ages but keep getting lost in the technicals of it and unable to make a decision.

As I understand it, your choices for a quality capture are either to splash out a lot of honk on a refurbished VCR with in-built TBC[1], or to separately buy a DVD recorder with TBC and run the signal through that, which sounds like a lot of clutter.

I have read about an interesting project to capture the RF signal from the VCR directly into a computer and then run a digital TBC. It's a fork of some software which was written to do the same with LaserDiscs (and seems to be working very well) but I don't think the VHS version is very stable at the moment:
https://github.com/oyvindln/ld-decode

The hardware it runs off is a custom build called the Domesday Duplicator. There are instructions on how to build it here if you're keen on soldering:
https://www.domesday86.com/?page_id=978

People will sometimes sell ready-built ones on the facebook group:
https://www.facebook.com/groups/2070493199906024/about

I really like the idea of this method, so have ended up paralysed by indecision when it comes to buying a VCR. I'd really like a reliable bit of kit that gives me proper archiving quality but doesn't take up loads of space.

My plan is to capture as losslessly as I can, then smash the thing through a topaz upscaler on a rented EC2

Can you explain what this is?
 1. Time Base Correction - think it just prevents dropped frames putting everything out of sync

Sebastian Cobb

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Re: Converting Videotape to Digital
« Reply #3 on: January 16, 2021, 01:39:32 PM »
Hmm that rf stuff looks a bit involved for a single tape, I don't know about PAL but it seems like NTSC is barely working anyway.

I was looking to use an PC capture device rather than a DVD burner.

I think TBC is only really present on prosumer SVHS machines but could be wrong. I'll try and get away without it first.

Topaz is some clever upscaling and noise reduction software for digital video. It has a machine learning upscaler that seems to do a good job. It takes a fair bit of computation and is best suited to using powerful GPU's (graphics cards) to do the calculations, I don't have a PC with a decent graphics card, so will rent one in Amazon's (ECS) cloud and do the processing there.

Some people have had good results upscaling Deep Space 9 DVD's to HD with it:
https://www.extremetech.com/extreme/306701-upscaling-star-trek-deep-space-nine-using-topaz-video-enhance-ai-review

Obviously I'm never going to get as good as that with VHS, and I'm wondering if the randomness of analogue video noise might screw up the software's ability to improve it somewhat but I'm seeing it as a bit of a learning project rather than a guarantee it'll work.

Re: Converting Videotape to Digital
« Reply #4 on: April 12, 2021, 05:07:02 AM »
Unfortunately the topaz enhancer thing is basically a scam, at least according to this thread where you can see people arguing about it:

https://forum.videohelp.com/threads/399360-so-where-s-all-the-Topaz-Video-Enhance-AI-discussion

lordsmurf is a highly respected user on digitalfaq and videohelp and has been at the video resoration thing for years, so I'd probably say it's very likely that he's the one who is correct here. The best results come from using filters in avisynth, which is free. Bit of a pain in the arse to figure out, but you could also use staxrip which gives you a nice GUI to work with and is also free.

Sebastian Cobb

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Re: Converting Videotape to Digital
« Reply #5 on: April 12, 2021, 08:20:33 PM »
I think most of the argument in that thread comes down to 'endlessly configurable' vs 'does acceptable job at the push of a button' (vim users vs IDE users springs to mind).

I'm sure it's possible to get better results through configurable software. However the expectation that everyone should be willing to invest lots of time learning the specifications of various video filters and figuring out what's best through trial and error, can be seen as a very subtle form of murder given we're all on scant amounts of borrowed time.

The software comes with an adequate free trial for my needs so cost doesn't come in to it.

Thanks for bringing it to my attention though, I will investigate it a bit.
« Last Edit: April 12, 2021, 08:31:24 PM by Sebastian Cobb »

Re: Converting Videotape to Digital
« Reply #6 on: April 13, 2021, 12:51:10 AM »
Yeah I suppose it is a trade-off between time and money. It might do more harm than good on a VHS capture though, because it already introduces heaps of artefacts when working from a decent, noise-free source. Probably the best you can do is just things like denoising and cropping and the other standard stuff, which can already be done with most encoding programs. Again, if you'd like to play around with something a bit more advanced but still not super tricky, then staxrip gives you a nice gui and way more filters than programs like handbrake or avidemux give you.

JesusAndYourBush

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Re: Converting Videotape to Digital
« Reply #7 on: April 13, 2021, 02:53:20 PM »
I was just using a DVD recorder/VCR combo until the VCR stopped working, so now I've been connecting another VCR to the DVD recorder.  I'm not doing anything flashy just a simple transfer, but the results look decent enough.

MojoJojo

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Re: Converting Videotape to Digital
« Reply #8 on: April 13, 2021, 03:30:20 PM »
Technology Connections made a video on this very topic https://youtu.be/ZC5Zr3NC2PY

I'm surprised I haven't posted it in the thread before - possibly I assumed you'd already seen it.

Re: Converting Videotape to Digital
« Reply #9 on: April 14, 2021, 01:42:38 AM »
Hmmmm, interesting. Read up more about it, and it seems everything's fine with the method, apart from the fact that the cheaper converters tend to do a poor job at scaling, which introduces artefacts and whatnot. Also you have difficulty with some of the issues faced by the person who made the video. Anyway the results will definitely be better than what you could get from some $30 USB capture card, and possibly even a DVD recorder. If you're not worried about opening your computer up, the best results are to be had from an internal PCIe capture card, with some models made by reputable manufacturers being cheaper than the HDMI converter setup thingy mentioned in that video.

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