Correct OBS settings to avoid smart TV stretching 4:3 VHS captures

[benawhile]

Hello
OBS on Linux system
Dazzle DVC100
Transferring PAL 4:3 VHS tapes to watch on smart TV or other 16:9 device

Does it make any difference whether I set up the OBS video to 720x576 or 1024x576?
1024x576 would be a 16:9 ratio.
I ask because the smart TV, which doesn't have a lot of picture settings, wanted to stretch some of the 4:3 videos to fill the whole screen, causing distortion, and I thought recording on 1024x576 would stop that.

[dellsam34]

Video capture native resolution is set by standard in the hardware chip to 720x576 (480 NTSC) and cannot be changed, If you set the capture software to capture in any resolution other than it the capture app will resize on the fly, Not to mention that OBS is not recommended for capturing analog video, Try vdub, AmarecTV or other Linux apps.

[benawhile]

Thank you.
Does that mean the Dazzle detects whether the input is PAL or NTSC and outputs accordingly?

I appreciate the advice about OBS but I am a noobie just beginning to crack it now I think, since I migrated to my more powerful Linux machine the frame jumping problem has been resolved. Results look quite good. I have been working on this for 2 months and if I go back to the beginning with a different software my wife might divorce me.
My laptop is Windows 10 Intel core i3 6100 4GB RAM, a Dell 3470 purchased 2016. In the OBS stats panel cpu usage was never above 20% but even so I was getting over 10% dropped frames. Not dropping any at all yet on Linux.

[dellsam34]

Thank you.
Does that mean the Dazzle detects whether the input is PAL or NTSC and outputs accordingly?

It samples at PAL or NTSC resolution, but the output is user defined, If you set it at the standard native resolution than it will output the samples (pixels) as they are without alteration, If you set it to a different resolution, a resize will happen, which is not recommended, you can do that later after de-interlacing.

[benawhile]

I set it for PAL-I in OBS on Linux. I can't type in a resolution manually on Linux. I could on Windows. But if it was wrong it wouldn't work. Of course.

Do you recommend de-interlacing? Looks OK at the moment on 25 frames per second with deinterlacing disabled

[Cornucopia]

De-interlacing disabled means the resulting file should still be interlaced (as how it was originally in analog world). This is not an issue for SOME software players (VLC, MPCHC, potplayer, etc) because they can either automatically or manually deinterlace during playback. However, some software player apps, and some/many hardware players, don't know how to properly handle interlaced material. In those instances, you get interlacing artifacts (mice teeth, smeared blending, etc.). That is why many here might suggest you deinterlace during your edit/cleanup/conversion stage prior to your final distribution/playable copy. When they do, they often would go 25i (aka 50i) --> 50p, rather than 25p, because it retains full motion smoothness (quality depending on Deint algortithm chosen). So really, it depends on how you intend to play it/use it.
This is similar to using native SD resolution, which is always non-square pixel AR. Depends on whether the app supports it. If you want to make the resulting file be usable by nearly ANYONE, during edit/cleanup/conversion, you would noise reduce, adjust levels, deint, resize, and then output to common codec (h264, h265, etc) in mp4 or mkv container. But that is not really necessary (nor recommended) when doing the original capture.


Scott

[benawhile]

Thank you for your time. I haven't looked ahead to the edit/cleanup/conversion stage yet but realised that after recording with OBS I would at least need to trim up the beginning and ends of the recording. I have openshot on my system and was intending to use that. I have heard KDENlive is better but will try anything that is advised here, but needs to be Linux compatible. They are not high quality video recordings and just need to convert them to a universal format that doesn't need a lot of space and retains reasonable quality.

[betwixt]

Flowblade - just my personal preference for Linux video work.

Brian.

[benawhile]

I've confirmed my "smart" 16:9 TV cannot display native resolution without stretching horizontally to fill the screen so somehow at some stage I will still have to add black bars at either side. So do you recommend that I do this *after* the capture stage? Will it be a straightforward process?

FWIW I have just done four OBS test captures to mkv of the same 20 second segment of VHS tape as follows
1 Capture device setting deinterlace disabled video setting 50 fps
2 Capture device setting deinterlace disabled video setting 25 fps
3 Capture device setting deinterlace yadiffx2 video setting 25 fps
4 Capture device setting deinterlace yadiffx2 video setting 50 fps
Result
All four capture files were roughly the same size, no missed jumped frames throughout

Played back in VLC and using the E key to advance one frame at a time:
2 and 3 contained 25 progressive frames in each second
1 and 4 contained 50 frames but every alternate frame was a repeat of the previous one.

It looks like although the 50 fps have twice as many frames they are still the same size in MB. Is that to be expected?

[davexnet]

Perhaps you should post a sample of some of your captures. 25 fps with deinterlace disabled should be the starting place.

[benawhile]

[Attachment 86167 - Click to enlarge] Is this what you want? That's the "not deinterlaced" 25 fps. It's how it appears on my PC monitor.
But my main problem now is to be able to watch this on my 16:9 smart TV with the black sidebars which VLC has added here. The smart TV stretches it, which I don't want. One solution is by changing the OBS video canvas and output settings from 720x576 to 1024x576 but that is not recommended here. I need to know how to do that later, on openshot, KDEN, Flowblade

[davexnet]

Is this what you want?

Not really, I was thinking of a short video sample cut direct from your capture

[benawhile]

No prob,

[Sharc]

I don't use OBS. Your file has an incorrectly (or missing) flagged DAR (Display Aspect Ratio).
Try attached. Does this play correctly as 4:3 on your TV?

[davexnet]

Your capture is already compromised because of it's 4:2:0 color space and interlaced content being encoded as progressive.

Best practice is to capture to a lossless codec (Lagarith, UT Codec, etc.) at 4:2:2 color space using
AmarecTV or Virtualdub.

If you want to stick to your current setup, see if there is any way to pass further parameters to the encoder. For example,
in vdub2 you can pass --tff to x264, this tells it to create proper interlaced output and the above problem does not arise.

I asked this very question to the forum back in 2020. See my question and the answer by jagabo immediately following
https://forum.videohelp.com/threads/398436-In-VirtualDub-where-is-the-capture-BITRATE-...ng#post2592253

[Sharc]

Best practice is to capture to a lossless codec (Lagarith, UT Codec, etc.) at 4:2:2 color space using
AmarecTV or Virtualdub.

+1. For proper capturing of interlaced video (like on VHS sources) avoid OBS like the plague.

@davexnet: SAR should be set to 12/11 in the x264 configuration, unless you resize to square pixels (or force the player/TV to display it as 4:3).

[Alwyn]

Your capture is already compromised because of it's 4:2:0 color space and interlaced content being encoded as progressive.

Dave, could you explain? That file, as far as I can tell, is Progressive; there's no jaggies and when you do deinterlace it, every second frame's a dupe.

And it will be 420 because that's the final output in H264.

[Alwyn]

@benawhile, as you've probably picked up, we don't think OBS is a good idea. I did some tests last which revealed some random, short glitches with field orders. You had to look for them though.

So, with my heretic's hat on now, try these settings for correct frame size/ratio output:

Settings>Output

[Attachment 86176 - Click to enlarge]

Settings>Video

[Attachment 86177 - Click to enlarge]

[davexnet]

Hi Alwyn, I didn't examine the source, my statement was more of a general point.
It's explained in the link I gave from 5 years ago,

[Sharc]

Interlaced 4:2:2 (true or PsF) should be correctly converted to 4:2:0 before (re-)encoding it interlaced as 4:2:0, using for example

ConverttoYV12(interlaced=true)

x264 displays a warning otherwise.

Edit:
Or when one deinterlaces the interlaced 4:2:2 capture, the conversion of the deinterlaced progressive 4:2:2 to 4:2:0 is

ConverttoYV12()  #default is interlaced=false

[benawhile]

I don't use OBS. Your file has an incorrectly (or missing) flagged DAR (Display Aspect Ratio).
Try attached. Does this play correctly as 4:3 on your TV?

Sharc, no it still gets stretched to fill the 16:9 screen by the TV. But the problem may be that this basic smart TV states in the instructions that picture format settings don't work for USB and Internet TV. And they are greyed out. Looking at the rest of the comments to see which i can answer, thanks everyone for your interest. Still prefer to stay with OBS as it's Linux compatible. And so far I get better results with Linux too. No skipped frames, yet.

[benawhile]

Your capture is already compromised because of it's 4:2:0 color space and interlaced content being encoded as progressive.

Best practice is to capture to a lossless codec (Lagarith, UT Codec, etc.) at 4:2:2 color space using
AmarecTV or Virtualdub.

If you want to stick to your current setup, see if there is any way to pass further parameters to the encoder. For example,
in vdub2 you can pass --tff to x264, this tells it to create proper interlaced output and the above problem does not arise.

I asked this very question to the forum back in 2020. See my question and the answer by jagabo immediately following
https://forum.videohelp.com/threads/398436-In-VirtualDub-where-is-the-capture-BITRATE-...ng#post2592253

Thanks davexnet, I am puzzled about the "4.2.0 colour space".
My settings for OBS are
Advanced>Video>Colour format: (from dropdown) NV12 8 bit 4:2:0 2 planes.
There are 7 others in the dropdown, one of them is a 4:2:2. It's P216 16bit 4:2:2 2 planes. Should I select that?
However, the OBS setting for the Dazzle source is "Video setting: YUYV 4:2:2."
The settings I am using are according to the Tim Ford video for basic vhs capture. He also says choose 601 colour space limited.

Will go through rest of your post bit by bit now...

[benawhile]

If you want to stick to your current setup, see if there is any way to pass further parameters to the encoder. For example,
in vdub2 you can pass --tff to x264, this tells it to create proper interlaced output and the above problem does not arise.

Within output settings I can select advanced settings. (not the same as the actual advanced settings in the menu)
From that the encoder can be set to CBR VBR ABR CRF. Tim Ford recommends CBR. Is that significant?

There is a box to type in x264 options. Should I put anything into that? Is that related to "pass --tff to x264,"

[benawhile]

@benawhile, as you've probably picked up, we don't think OBS is a good idea. I did some tests last which revealed some random, short glitches with field orders. You had to look for them though.

So, with my heretic's hat on now, try these settings for correct frame size/ratio output:

I couldn't get it to record at all on those settings.
Got this error: "Unknown error occurred while recording Couldn't initialise muxer"
Had that error before when experimenting with resolution settings and usually means I have to restart to get to record again.
Had this trouble before if canvas and output not the same size.
So I changed the canvas too, to 768x576.
It recorded, but no different from before. What was expected with those settings?
I know 768 gives the correct 4:3 ratio but stretching that to 16:9 would hardly look better than stretching 5:4 to 16:9.

Wrt field orders, I'm guessing that means fields getting reversed in time so for example going frame by frame a car will go backward for one frame then two frames ahead in the next frame? Interestingly I haven't found that (yet!) and as said before, frames much better on this system than on the old Windows 10 laptop, even though cpu remained below 30% I was losing about 1 frame in 8. So for example the 25 frames were still there but frames 5,6,7 say, were all duplicated. But all fine now.

[benawhile]

Your capture is already compromised because of it's 4:2:0 color space and interlaced content being encoded as progressive.

Best practice is to capture to a lossless codec (Lagarith, UT Codec, etc.) at 4:2:2 color space using
AmarecTV or Virtualdub.

If you want to stick to your current setup, see if there is any way to pass further parameters to the encoder. For example,
in vdub2 you can pass --tff to x264, this tells it to create proper interlaced output and the above problem does not arise.

While waiting for a response I have tried the 4:2:2 as per my post #22, but it wasn't accepted as it was a
"high precision format" not compatible with x264.
I was able to insert --tff into the box as per #23. (Really out of my depth by now) but managed a recording. Attached.

[lollo]

While waiting for a response I have tried the 4:2:2 as per my post #22, but it wasn't accepted as it was a
"high precision format" not compatible with x264

You should not capture into a (generally) lossy codec, but 720x576, YUV 4:2:2, interlaced, lossless.

And while there, OBS is not recommended. If you had inserted frames problems in Windows you had to solve that problem there, not migrate to Linux and use OBS just to add additional variants.

[davexnet]

Yes, as mentioned earlier 4:2:2 is intended for lossless codecs such as mentioned previously - Lagarith, UT codec.
Can OBS use these?

However, for x264, getting the -tff to work and create a proper interlaced file while using a high bitrate of low CRF value
might be worth looking at within OBS, but this is the second best option

[benawhile]

While waiting for a response I have tried the 4:2:2 as per my post #22, but it wasn't accepted as it was a
"high precision format" not compatible with x264

You should not capture into a (generally) lossy codec, but in YUV 4:2:2, interlaced, lossless.

And while there, OBS is not recommended. If you had inserted frames problems in Windows you had to solve that problem there, not migrate to Linux and use OBS just to add additional variants.

Thank you, could you clarify?
I have YUYV 4:2:2 set as the video format for my capture device. Is this what you mean by the lossy codec?

[lollo]

I have YUYV 4:2:2 set as the video format for my capture device. Is this what you mean by the lossy codec?

No, that's the Color Space. The codec should be a lossless type like HuffYUV, Lagarith, UT Video (h264/x264 can be lossless as well).
Davexnet already explained you all that

[benawhile]

Lollo
Yes, but where is the setting for it it? How do I find it and change it?
Are we at cross purposes? The colour space options don't say anything about 4:2:2. The colour format options are 4:2:2, 4:2:0, 4:4:4 but as stated earlier if I change it I can't record, unless maybe I change another setting, but which setting?

Could someone tell me:
What is the codec? Is it x264, the video encoder in Recording settings? I can change it to FFmpeg HEVC or H.264, or AOM AV1.
I have added --tff but can't tell if that has made a difference.

It looks like I can't change the colour format from NV 4:2:0, if I try then it won't record, although maybe it would if I changed another setting, but I need advice about what to change.
The video format setting for my dazzle capture device is YUYV 4:2:2

I can tell you as much as you want about the OBS settings, if you tell me how they need to be changed to get the best result with what I have, but I cannot use another program, all the recommended ones are Windows only. Will send lots of OBS screenshots if that will help. Only problem is that my PC can't screenshot whole open dropdown lists for some reason.