OBS - MAC - PAL-NTSC VHS Transfer Settings + Process (please help make this definitive!)

[Slaughter]

Hi all,
I've come back to VHS transferring for a doco I am working on and had a few problems, so I thought it sensible to create
a single, all info in one place thread which combines key info from the following places (see links below). I have raised a few questions below and would greatly appreciate any advice on these. Please feel welcome to contribute to this thread in any way you can to make it definitive and useful as possible. There is no such thing as a dumb question. I am NO expert and am seeking as much help and clarification as you are.
I'd also appreciate it if those who know more than me can please check my settings (as per screenshots) and provide any advice indicated there.
Thanks!

Source threads quoted:

Correct settings for capturing VHS (Mac) - OBS not showing base resolution options for NTSC - PAL

Helpfully, Black Magic have effectively junked their previously wonderfully useful Black Magic Intensity Shuttle device by refusing to provide drivers for compatibility for Mac OS past Mojave. Equivalent quality devices are now ridiculously costly. So I've been trying to set up an alternate Mac...

obsproject.com

Correct settings for capturing VHS - please help a newbie

Hello! I am new to OBS and to video editing in general, truthfully I will probably only be using the software to convert old VHS tapes into digital format. I hope someone can help me make sure I have the right settings for the purpose. My current setup has resulted in black bars on both sides of...

obsproject.com

Digitizing VHS Tapes Using OBS - Tim Ford Photography & Videography

Did you know you can digitize your VHS tapes using OBS for under $20? Well, you can, and this post tells you how to do it!

timfordphoto.com

BASE RESOLUTION
768x576 (PAL)
720 x 480 (NTSC)

By default, OBS won’t show you the base resolutions for VHS. You just have to *type in the values you want*.

FRAME RATE
For PAL, capture at 50 PAL (best results for deinterlacing)
For NTSC, capture at 30 or 60?

QUESTIONS:

VIDEO > SETTINGS
OBS forces you to choose a downscale filter, even after you ensure your base and output resolutions match. Is the correct choice Lanczos? Or does it not matter given you aren’t actually downscaling?

OUTPUT (SIMPLE MODE)
ENCODER - forces you to choose from one of two “Software (x264)” modes. There is no other choice.
AUDIO - why do we only have lossy audio options, maxing out at 320kbps? How do we change this to a lossless or less lossy codec?

Please note that *I* have chosen .mov as my recording format as FCPX will not read .mkv files, requiring those files to be converted.

OUTPUT (ADVANCED MODE)
*NOW* you can choose a hardware encoder option, but whenever I muck around with this section I get frame drops as the computer seems to be working a lot harder after selecting a hardware encoder . For optimal transfers, should we go with SIMPLE mode as per screenshot, or ADVANCED and if so, what are the optimal settings?

A whole lot of stuff changes when you choose ADVANCED mode and from here, my brain melts... so I've been using SIMPLE mode...

"ADVANCED" PANEL
(NOT MODE but the last panel named "ADVANCED")
Do we need to make any changes here?

DEINTERLACING
Right click on your “VHS Capture” source (in the “Sources” window) and hover over “Deinterlacing.” Select “Yadif 2x” and “Top Field First.” Without this setting, you’ll see jagged lines in your recorded video whenever there’s any significant movement.
NOTE – you don’t need to use this setting if you are digitizing with the intent to play your files on a DVD player:

STATS PANEL
You should also have the Stats panel open so you can see if the frames are dropped to due to encoding lag, or rendering lag after fixing the recording settings.

If the target disk is too slow, it will affect your recording performance.


____________________________________________________________________________
TRANSFER CHAIN FYI
I am running OBS 25.0.7 on a Mac running Mojave 10.14.6 with Blackmagic Intensity Shuttle.
FYI I am never, ever making a single change to this chain, OS or OBS version. I have learned the hard way to keep this chain 100% static. My Blackmagic device will not work with a newer OS and is no longer supported. This Mac is not online, ever. I use it purely for VHS transfers.

 

[AaronD]

FRAME RATE
For PAL, capture at 50 PAL (best results for deinterlacing)
For NTSC, capture at 30 or 60?

59.94

Black and white NTSC was 60, same as the power frequency where it was used, for the same reason that PAL is 50. But the backwards-compatible addition of color, was done with a "color burst" at the start of each line, which is just a few cycles of the carrier frequency that the color information is modulated on. That re-synchronizes the otherwise-free-running de-modulator, so it can pick out the two channels of color information from the same carrier which is superimposed on the brightness signal. B&W sets then, would only be *slightly* blurrier, if at all.

The addition of that "color burst", added a small amount of time to each line, and so the overall speed was reduced just slightly to accommodate it. Only the sending end was actually locked to the power line - TV sets always sync'ed to the signal and ignored the AC power - so the slight slowdown didn't change anything about how they worked. And by the time color was added, the original requirement for the sending end to grab something convenient was also gone.

Also, that 50 or ~60 (59.94) fps is *interlaced*. So you only get every other line in each "frame", and not all of them. If you wait to get all of them before counting a frame, that would be 25 or ~30 (29.97) fps...but you still have 50 or ~60 snapshots in time (*), so you can't just mash the two fields together without a "combing" effect on horizontal motion. That's what the various de-interlacing algorithms are for, with varying expense and performance.

(*) Actually, it's not even a snapshot at all, but a continuous scan of a single dot across the entire screen. Whatever happened at the moment the dot was in each position, is what gets recorded. So every point on the screen is in fact a different time.

 

[AaronD]

why do we only have...

____________________________________________________________________________
TRANSFER CHAIN FYI
I am running OBS 25.0.7 on a Mac running Mojave 10.14.6 with Blackmagic Intensity Shuttle.
FYI I am never, ever making a single change to this chain, OS or OBS version. I have learned the hard way to keep this chain 100% static. My Blackmagic device will not work with a newer OS and is no longer supported. This Mac is not online, ever. I use it purely for VHS transfers.

Because you insist on using an old version. Newer versions have addressed a number of these restrictions.

 

[AaronD]

VIDEO > SETTINGS
OBS forces you to choose a downscale filter, even after you ensure your base and output resolutions match. Is the correct choice Lanczos? Or does it not matter given you aren’t actually downscaling?

Again about newer versions.

If there's no scaling, and you insist on using an old version, I'd choose a more basic scaler, just so it does actually reduce to each pixel mapping straight through. The fancier ones might look better when they do scale, but they're not necessarily transparent when they don't.

 

[Slaughter]

(EDITED)
Can anyone confirm that a new version of OBS will work under 10.14.6?
I'm very wary of changing things up....

Because you insist on using an old version. Newer versions have addressed a number of these restrictions.

 

[Slaughter]

I'd choose a more basic scaler, just so it does actually reduce to each pixel mapping straight through. The fancier ones might look better when they do scale, but they're not necessarily transparent when they don't.

Are you able to clarify which scaler is a "more basic" one of the scaling options OBS requires you to choose from? I assume most reading this will not be any wiser... I'm certainly clueless on that myself.

Thanks for that interesting background you posted on NTSC and frame rate, btw! :)

 

[Slaughter]

BTW is there a way to edit original posts? I need to amend my comments on audio.

I missed the fact that the audio info I quoted is actually from the "streaming" component of OBS so probably does not apply for the transfer process we are talking about here.

Under the AUDIO tab (see attached) the indication is 44.1 / Stereo can be set easily enough - have I set this up correctly for lossless as possible transfer?

 

[Slaughter]

Am trying to find the latest version of OBS that will work under 10.14.6 but can't seem to find any OS compatibility info...
If anyone knows, that info would be appreciated...

Releases · obsproject/obs-studio

OBS Studio - Free and open source software for live streaming and screen recording - obsproject/obs-studio

github.com

[EDIT] I've just answered my own question...

macOS Versions | OBS

OBS Knowledge Base. What version of OBS Studio can I run on my Mac?

obsproject.com

 

[Slaughter]

I just attempted to "upgrade" to the latest version of OBS that will work under 10.14.6, which is version 27.2.4.
It BROKE my transfer chain. Would NOT recognise input, no matter what I did. Black window all the time, every time.
When I "downgraded" back to 25.0.7, voila, all working just fine again.

Because you insist on using an old version. Newer versions have addressed a number of these restrictions.

Sorry, but it's not me that is insisting - it is my system.

Unless you have a viable solution for:
1. The fact that my Blackmagic device is not supported past OS 10.14.6
2. Later versions of OBS do not allow me to digitize tapes
3. I can't upgrade my machine past 10.14.6, it is too old

Attempting to use a later version of OBS just now has proven my point: If you have a transfer chain that works, STICK TO IT.
Do NOT make changes.

Ok, getting back to the topic at hand... see my last Q's about downscale filtering etc :)

 

[AaronD]

Unless you have a viable solution for:
1. The fact that my Blackmagic device is not supported past OS 10.14.6
2. Later versions of OBS do not allow me to digitize tapes
3. I can't upgrade my machine past 10.14.6, it is too old

You're probably looking at a new machine then. Or just live with the limitations. Sorry.

BTW is there a way to edit original posts? I need to amend my comments on audio.

Yes, but it often invalidates replies, which leads to more confusion for people who read the thread later.

There are probably restrictions on new users doing that, to avoid spammers posting something innocuous and then changing it later, but if you have it, it'll be here:

Under the AUDIO tab (see attached) the indication is 44.1 / Stereo can be set easily enough - have I set this up correctly for lossless as possible transfer?

It's *always* lossless (completely uncompressed, even), until it gets to the encoder. That's in Settings -> Output.

Are you able to clarify which scaler is a "more basic" one of the scaling options OBS requires you to choose from? I assume most reading this will not be any wiser... I'm certainly clueless on that myself.

The list is in order from basic (little effort, bad results if actually scaling) to fancy (lots of effort, good results):

If not actually scaling, I'd pick the Bilinear one.

It helps to imagine both grids overlaid on each other, with the same overall size regardless of pixel count, so that one is finer than the other.

Bilinear takes the two source pixels on either side of the destination pixel, in each direction, and computes their weighted average. Not scaling at all, reduces that to picking the same source pixel four times, so of course it ends up the same.

The others might reduce similarly, or they might have multiple stages, some of which always use neighboring pixels. If it's the latter, then not-scaling is not completely transparent.

 

[Slaughter]

If not actually scaling, I'd pick the Bilinear one.

Thanks for all of this detail Aaron!
I'll try that, and will do some A/B comparisons with Lanczos as well given that's what I've used for 6 hours worth of transfers last week... hopefully I won't feel compelled to do them again....

The "edit" option does not exist in my OP. That's why I asked...
Weird that I am coming up as a "new" user... I guess "age" is determined by no of posts? Dunno...

You're probably looking at a new machine then. Or just live with the limitations.

I'm fine with the version of OBS that I'm stuck with. I never set out in my OP to complain about it...
I'm only seeking clarifications and best process.
My rig works. The version of OBS I have is a little confusing and this thread is helping with that.
General principals etc are always helpful as well.
I don't do VHS transfers often enough to ever become fully adept with it. 2 years can go by between transfers....
So I really appreciate all your input here!

 

[AaronD]

Weird that I am coming up as a "new" user... I guess "age" is determined by no of posts? Dunno...

Yeah, I think so.

 

[Slaughter]

Just a quick one on scaling - I discovered that there is a scaling disable option when you right click on the input profile you're using... obviously confusing when there is a separate scaling section with *no* disable option in the main settings, but on A/B comparison between scaling methods selected in settings *plus* scaling disabled via this different menu, I am seeing absolutely no difference in output - which leads me to conclude that scaling is in fact disabled and / or no scaling is happening when I have my base and output resolution set as uniform. Obviously only useful info for folks like me who are "stuck" on this version of OBS... but still good to have this clarified.