VHS transfer with Blackmagic, problems?
 

Hey folks,

I finished a first capture sample and would like to know where I'm at and what I could do better.

Hardware:

- Movie on VHS tape bought from Amazon a couple days ago
- JVC HR-S9500U (S-Video out, TBS on)
- Blackmagic Mini Converter - Analog to SDI
- Blackmagic UltraStudio 3G Recorder

Software:

- Blackmagic Media Express
- Blackmagic Davinci Resolve 17

Captured at 720p, increased audio level, cropped / framed head switching noise and sides, developed at 1080p.

https://www.youtube.com/watch?v=0nge8B-6a-s

Why would you capture at 720p? It should be 480i or 576i for PAL. Do you get audio to video drift since BM mini converter lacks frame TBC?
If de-interlaced why interlace effects are still on?

In my research I found a guy who said that 480i would cause pixilation once it becomes a digital signal. He suggested to capture with 1080, I did a compromise in order to keep the file size somewhat manageable.

I haven't done any long captures yet, will do a movie tomorrow and see if the audio is out of sync.

I don't know anything about (de)interlace, can you explain in detail?

Who ever told you that needs his brain checked, Regardless what you output at, your capture device will always capture analog SD at no more than 720x480, Your capture software just resizes on the fly to whatever resolution you peak, The down side of resizing on the fly VS resizing later is if there is a problem you can't go back and resize, you will have to recapture the entire tape. Stop making that mistake, Capture first, and later de-interlace, crop and resize or whatever you feel like doing, If something goes wrong, you have the original 480i files.

De-interlacing is blending the fields together based on a scheme, there are quite few schemes out there, you need to look it up and learn it, it's hard to explain with words.

OK, I read up on interlacing, and just checked my settings. I was capturing in 525i 59.94 NTSC after all. There is no 480i. Is 525i my best option?

De-interlacing is automatically done in DaVinci. It was set to "normal". I changed it now to "High".

Is AVI 8 the best file format for this content?

Export in DaVinci was 1920 x 1080, 29.97, MP4 (suggested for the YT upload), H.264. Any other suggestions?

I did the changes like cropping in DaVinci.

Thank you for your help!

525i is just the standard, the actual resolution is 480i. 525 includes timing lines that are not part of the active video area.
Your capture settings are correct, 525i, 8bit YUV, the resulting files should be lossless AVI 4:2:2 720x480 59.95 fields per second.

No idea. Youtube butchers in multiple ways, and that file looks terrible as a result. Actual capture sample required. It doesn't need to be huge, and nobody will download large file anyway.

I guess. Blackmagic has known issues with capturing VHS. It's not suggested for a reason.

Wrong. Capture 720x480 max.

You made a mess of the interlace.

Correct.

Correct, no frame TBC is this workflow, problems will happen. Audio sync is merely one tell-tale, and BM cards actually have worse symptoms than normal.

Geometry was altered while interlaced.

That person is an idiot. Where did you read that, or see that? Because it's complete BS, not an ounce of truth to it.

It will be. Also be prepared for infamous Blackmagic "black frames".

Analog SD video (and old CRTs) is interlaced, 59.94 frames per seconds, but out of phase. You see half of one frame, and half of another, at the same time. It's a cheat that goes back a century, to allow decent motion on screen. The image combs. Modern displays are progressive, single image shown at a time, like film. To shown intelaced content on modern progressive displays, it must be deinterlaced, or you'll look at lots of lines. There are really horrible ways to do it, and few good ways to do it. So you must be careful. You cannot (at least easily) resize interlaced video, only deinterlaced.

Correct. :congrats:

Hint: Only use QTGMC, everything else is currently crap methodology ("schemes").

Full NTSC is 525i, but you never capture beyond 486i, usually just 480i. Note that anything large than x480 (NTSC) is not usable data, not picture data.

Do not do this. This is the an aforementioned crap method. :no2:

What is "AVI 8" ?
AVI, yes, just a wrapper for a codec.
But 8?

You're skipping steps. You must prep capture files for advanced editing, otherwise you'll just screw up the quality, often unwatchably so. The step you've skipped is the deinterlaced, resize AR, mask/crop, etc. Only then can you color correct. You cannot just cram it into Resolve, and get usable results.

You're making a lot of mistakes, but at least you're doing so with samples. Not foolishly capturing everything, and only later realizing you made mistakes. So you're doing okay. Just keep learning, keep processing samples. Don't be stubborn, don't fight video (it will fight bad, you always lose). And you'll surely get there. :)

And also be sure that you really need deinterlacing and not inverse telecine instead.

Is this correct? I thought interlaced video was 59.94 fields per second that are blended together during the deinterlacing process into 29.97 frames per second (or, depending on the deinterlacing process, doubled into 59.94 frames per second).

Interlace artifacts (as opposed to combing) ie the jaggies are when you're looking at both fields together eg when looking at a VHS capture in Virtual Dub. You'll only see it on moving objects.

That video isn't "terrible". I'd watch it on my 55" as-is and be satisfied. Sure, it needs work, principally to be de-whatevered but gee, you're being a bit harsh there, LS.

It's correct. You can separate all 59.94 temporal full-sized fields as half-sized frames, though their is overlap in the data.

Advanced info, OT for this thread, but mentioning just in case...
And contrary to some opinions, you're not necessarily "throwing away half" of the temporal/interframe data from a deinterlace. Mostly intraframe data. The idea of "throwing away" comes from simple ideas of 59.94, without regard to the half size (aka, missing data). It has to be interpolated to restore full-size frames. So you do lose some going to 29.97 progressive (or 25 PAL), but it's not half as often touted. Half is wrong. Maybe 25%. Or less. It really depends on the content type.

Not often. The main observance of "jaggies" or "stair step noise" is from drop-field deinterlace. Jaggies are a main reason better deinterlace was sought, and even QTGMC isn't perfect here (but can be close most often).

Telecined content is the usual suspect for noticing interlace artifacts on interlace, not actual interlaced sources.

That video is definitely terrible, with massive interlacing lines in the image.

Stuff like that gives me a headache. It's the main reason I never watch Lone Ranger on The Cowboy Channel, interlace mess that gives me a headache. (Rural Media Group tends to screw up a lot of their broadcasts, be it interlace horrors, or bad AR, or postage stamping.)

Although not always accurate, for starters have a look at http://www.100fps.com/

Deinterlacing at the same frame rate such as QTGMC(FPSDivisor=2) or QTGMC().SelectEven() removes half of the temporal data. The impact on the final result can be 0% if there is no movement or 100% in the opposite case. Today, almost everyone deinterlaces at double rate output.

That's not at all true, and for multiple reasons. There's a thread at VH where it took quite a bit of work to turn a video into 59.94, because it would create artifacts from the on-screen date. Just running it as 29.97 prevented the artifact.

It's never 100%.
In fact, 100% that it's never 100%. :laugh:

Special case, not significant! ;)

:) :)

I wish that were the case. It's not. :(

Thanks for all the info. I will have to re-read a couple times and take notes, and get back to certain topics.

I don't own a desktop computer, only ThinkPad laptops. The one I'm using right now is a workstation P52 with XEON CPU, 128 GB RAM, 2 x SSD in a raid, Thunderbolt, you get the idea. So I can't make use of any PCI capture cards. Are there any better hardware capture solutions that connect to Thunderbolt / USB C? I paid 300 bucks for the two BM devices. Is there anything in that price bracket.

I don't want to get yet again into my typical "have to buy the best out there" behavior. I have gear for countless hobbies and the truth is, I don't use it anymore once I move on to a new hobby. Reloading for instance, I own 4 presses and gear worth 30k. So I'm trying to keep this new hobby reasonable.

How can I best deinterlace with QTGMC? Didn't find this in DaVinci to begin with. Virtualdub?

8 bit.

DaVinci did it but I guess I'm supposed to turn it off and get it done before any editing.

That's interesting. I don't know which specific thread you're referring to but I once had a similar issue with computer-generated content. I fixed it by changing the QTGMC preset, I think from "Medium" to "Fast," and the glitch went away.

So I was getting ready for the long capture test to find out if I'm dealing with video / audio drifting, and all of the sudden this tearing shows up, see attached screenshot. I searched for this issue and read different threads, but it is still not clear what causes this.

I don't think that my VCR has a problem. It plays other tapes with home recordings just fine.

This new tape is a newly bought movie on tape, from Amazon.

When I turn of TBC on the VCR, the video goes black and only shows a frame or so every few seconds, the audio is also heavily interrupted. When I turn TBC back on, audio is clear and video shows the flagging, but irregularly.

I'm watching the material on the Blackmagic Media Express capture software, so it went through the analog to SDI converter, and the 3G recorder.

Am I dealing with macrovision and the TBC in the VCR gets most of it out, leaving only the tearing behind?

Perhaps. Broadcast rack-mount TBCs do not always fully and properly replace parts of the signal that contain anti-copy and other error. Again, the difference between TBCs made for consumer VHS, and those made for broadcast sources. A TBC is not a TBC. It's wide encompassing term that can mean many things, with many variants.

This TBC is not suggested.
This capture card is not suggested.
You're seeing why that is.

This is not a problem for me since I'm not going to capture any tapes with copy protection. My only interest is in home recordings from eBay, flea markets, etc. Only used this tape to have a good source tape for testing. Looks like I'll have to record my own test tape.

Will come back once I have done a long capture so that I know if I have a audio drifting issue. Will also test other de interlacing options.

But you're missing something. Anti-copy (Macrovision and others) is just an artificial video errors. Natural errors can appear similar, and still trip up detections. Again, Blackmagic cards are very inferior to any tape signal defects, and all VHS signals are defective in some way. You're fighting the grain by using it, pissing uphill.

I'm running out of ways to make you realize this isn't the card you're looking for. (Waves Obi-wan hand in front of you. :D)