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

[lollo]

I am not familiar with OBS, so I can't help here, sorry.

My talking about color space and codecs referred to generic concepts, nothing specific to OBS.

My suggestion is that you go back to the windows enviroment if possible, and capture with AmarecTV or VirtualDub. We can help in reducing/eliminate the inserted/dropped frames if they are not dependent on the conditions of the tape.

[Sharc]

I was able to insert --tff into the box as per #23. (Really out of my depth by now) but managed a recording. Attached.

Doesn't look right. Your --tff had no effect. It is encoded as 25fps progressive with blended frames at scene changes (76, 145, 252, 357) and still missing or incorrect DAR flags.
A trustful capture would be needed (not from OBS) for more and targeted advice.

[benawhile]

OK I'm setting up amarectv on the laptop, will get back tomorrow, however I am concerned that this thread has taken on a life of its own. By the time I came to post #9 I was mainly asking for a simple way to add black sidebars to allow my very basic smart TV to display 4:3 with no distortion.
If I can get a trustful capture from Amarec tomorrow and that can help with a bit of fine tuning for my setup all well and good.
I hope I don't sound ungrateful, I am very appreciative, but have bitten off more than I can chew.

[davexnet]

OK I'm setting up amarectv on the laptop, will get back tomorrow, however I am concerned that this thread has taken on a life of its own. By the time I came to post #9 I was mainly asking for a simple way to add black sidebars to allow my very basic smart TV to display 4:3 with no distortion.
If I can get a trustful capture from Amarec tomorrow and that can help with a bit of fine tuning for my setup all well and good.
I hope I don't sound ungrateful, I am very appreciative, but have bitten off more than I can chew.

If you're inclined, hang around in the forum for a while and you'll soon be an expert!

[Sharc]

...however I am concerned that this thread has taken on a life of its own. By the time I came to post #9 I was mainly asking for a simple way to add black sidebars to allow my very basic smart TV to display 4:3 with no distortion.

If it's only this you want, run this simple ffmpeg commandline on your clip in post#25:

ffmpeg -i "2025-03-19 16-21-04 --tff.mkv" -c:a copy -c:v libx264 -preset slow -level 40 -crf 20 -vf "crop=684:560:12:0,scale=w=960:h=720,pad=1280:720:-1:-1,setdar=16/9" "16-9.mkv"

Does your TV play it correctly?

[Alwyn]

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.

Just an attempt to find a standard frame-size that doesn't require flagging that would stop your TV stretching. You are right, 5:4 or 4:3 stretched to 16:9 isn't good.

If you have a lot of these vids, I would strongly suggest you upgrade your TV. All modern TVs will respect the 4:3 shape without burned-in side bars or at least have controls to set the screen display to 4:3. Burned-in side bars are not desirable, because they drastically reduce the size of the actual video when viewed on a non-widescreen display such as a 4:3 computer screen eg laptop, a 4:3 tablet such as an ipad or a phone that's held upright.

If you do really want sidebars, then it's preferable to capture losslessly, otherwise you're re-encoding lossy H264 (as Sharc has done with FFMPeg) when you add the bars after you've captured. Unless you've done the recording at very high bitrates, you're reducing quality with every re-encode.

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!)

Yes, but don't over-worry; the pixel-peepers found one or two instances in a video of a few minutes and only over a frame or two. Depends on how serious you want to get!

I couldn't get it to record at all on those settings.

Odd. It works here with without issue. Possibly your Dazzle drivers or the Linux+OBS combination.

[Sharc]

If you do really want sidebars, then it's preferable to capture losslessly, otherwise you're re-encoding lossy H264 (as Sharc has done with FFMPeg) when you add the bars after you've captured. Unless you've done the recording at very high bitrates, you're reducing quality with every re-encode.

This "quality loss" of a single reencode - even at very moderate bitrates - is much less damaging compared to OBS' preceding mistreat of interlaced video . I have no better suggestion for solving the OP's request for a simple method to add sidebars for his not-so-smart TV.

[rgr]

Hello
OBS on Linux system

Don't you have any other software on Linux? OBS is not suitable for this.

[rgr]

I've confirmed my "smart" 16:9 TV cannot display native resolution without stretching horizontally

Don't you have an Aspect feature somewhere in your TV options (or in remote)? It might even be in the properties for that input.

[benawhile]

File from AmaRectv attached, and report file

[benawhile]

...however I am concerned that this thread has taken on a life of its own. By the time I came to post #9 I was mainly asking for a simple way to add black sidebars to allow my very basic smart TV to display 4:3 with no distortion.

If it's only this you want, run this simple ffmpeg commandline on your clip in post#25:

ffmpeg -i "2025-03-19 16-21-04 --tff.mkv" -c:a copy -c:v libx264 -preset slow -level 40 -crf 20 -vf "crop=684:560:12:0,scale=w=960:h=720,pad=1280:720:-1:-1,setdar=16/9" "16-9.mkv"

Does your TV play it correctly?

I'm not sure what I am supposed to do. How do I run a command on a file? If that's what you did to the file you attached, I am sure it will play correctly because with the black bars it's 16:9.

[benawhile]

I've confirmed my "smart" 16:9 TV cannot display native resolution without stretching horizontally

Don't you have an Aspect feature somewhere in your TV options (or in remote)? It might even be in the properties for that input.

No, it's a characteristic of the TV, a budget Smart tv, that picture format is disabled/greyed out except for the "Watch TV" HDMI input.

Wrt VHS capture software for Linux, I've had another look but still found nothing except OBS a user at my level.

[Sharc]

I'm not sure what I am supposed to do. How do I run a command on a file? If that's what you did to the file you attached, I am sure it will play correctly because with the black bars it's 16:9.

Run this commandline under linux. It does exactly what you requested, namely rescaling your progressive OBS capture and adding black sideborders to the input file (-i "your_source"), delivering a correctly scaled, undistorted 16:9 output, in a most simple manner. You need to have an ffmpeg.exe on your system of course.

It's not a justification or even recommendation for using OBS, but as OBS seems to be the only app you can use, it may solve your 16:9 TV problem. Check out my attachment in post#35 to verify that it behaves on your TV as expected.

[benawhile]

Thanks, will try that

[Sharc]

File from AmaRectv attached, and report file

A plethora of lost frames, unfortunately. Probably your system or HDD is too slow, or the resources of your laptop were consumed by something else (ambitious virus scanner?). But otherwise the Amarec is the better capture compared to those before. It is sharper and has more details and is 4:2:2 which is fine. The source seems to be PsF (progressive video), - unless the dazzle applied some deinterlacing..... not sure.
Good start, just use a faster system to avoid dropped frames.

[lollo]

Too many inserted frames. In addition to what Sharc properly suggested, put PC offline, disable anti-virus, terminate all processes running in background, capture to a dedicated hard drive or a fresh partition of the unique hard drive, set AmarecTV to "High" priority, do nothing while capturing, etc.

[benawhile]

I'm not sure what I am supposed to do. How do I run a command on a file? If that's what you did to the file you attached, I am sure it will play correctly because with the black bars it's 16:9.

Run this commandline under linux. It does exactly what you requested, namely rescaling your progressive OBS capture and adding black sideborders to the input file (-i "your_source"), delivering a correctly scaled, undistorted 16:9 output, in a most simple manner. You need to have an ffmpeg.exe on your system of course.

There is a problem getting ffmpeg onto my Linux pc. When I type ./configure I get this error, reported often on the net,

"gcc is unable to create an executable file.
If gcc is a cross-compiler, use the --enable-cross-compile option.
Only do this if you know what cross compiling means.
C compiler test failed."
I haven't found a solution yet but was able to get ffmpeg on to the windows laptop. Could you kindly give me a windows version of the command?

[Sharc]

Could you kindly give me a windows version of the command?

Copy/paste that comandline of post#35 into a text editor like notepad, then save it under a name of your joice as a text file with the extension .cmd, like
mycommand.cmd for example.
Then double-click on it and let ffmpeg do the job (assuming ffmeg.exe is in the path, otherwise you'd have to specify the full path instead of just putting 'ffmpeg' in the commandline.

[benawhile]

Could you kindly give me a windows version of the command?

Copy/paste that comandline of post#35 into a text editor like notepad, then save it under a name of your joice as a text file with the extension .cmd, like
mycommand.cmd for example.
Then double-click on it and let ffmpeg do the job (assuming ffmeg.exe is in the path, otherwise you'd have to specify the full path instead of just putting 'ffmpeg' in the commandline.

I don't fully understand. I followed the wikihow instructions for installing ffmpeg. I put the ffmpeg folder directly on local disk C and then entered this in command prompt:
setx /m PATH "C:\ffmpeg\bin;%PATH%"
and it successfully installed. I've put C:\ in front of your command and saved it to the desktop. The video file with the same name is there too. Nothing happens when i double click the .cmd file. What have I done wrong?

[Sharc]

Could you kindly give me a windows version of the command?

Copy/paste that comandline of post#35 into a text editor like notepad, then save it under a name of your joice as a text file with the extension .cmd, like
mycommand.cmd for example.
Then double-click on it and let ffmpeg do the job (assuming ffmeg.exe is in the path, otherwise you'd have to specify the full path instead of just putting 'ffmpeg' in the commandline.

I don't fully understand. I followed the wikihow instructions for installing ffmpeg. I put the ffmpeg folder directly on local disk C and then entered this in command prompt:
setx /m PATH "C:\ffmpeg\bin;%PATH%"
and it successfully installed. I've put C:\ in front of your command and saved it to the desktop. The video file with the same name is there too. Nothing happens when i double click the .cmd file. What have I done wrong?

Change .cmd to .bat and try again. And remove the C:\ in front of the ffmpeg.

Edit:
If nothing helps
- unzip the attached .zip to your desktop
- open the bena folder
- double click on mycommand.cmd

[benawhile]

Works now. I removed the C:\. Didn't change to .bat. Works on a single click, not a double! That's probably one of my previous file and folder settings.
Thank you many times

[Sharc]

Great.
You may also want to add on a new line in the .cmd file:
pause

The window will then not close immediately. Good for debugging.

Edit:
Just in case your TV refuses to play the new file, add
-bluray-compat 1
in the commandline

[benawhile]

TV plays it ok. Where do you add Pause? at the very end after a space?

[Sharc]

TV plays it ok. Where do you add Pause? at the very end after a space?

ffmpeg -i "2025-03-19 16-21-04 --tff.mkv" -c:a copy -c:v libx264 -preset slow -level 40 -bluray-compat 1 -crf 20 -vf "crop=684:560:12:0,scale=w=960:h=720,pad=1280:720:-1:-1,setdar=16/9" "16-9.mkv"

pause

-bluray-compat 1 added as well to be on the safe side.

Edit:
And take note that the basic commandline above applies for progressive video. If you one day manage to capture properly interlaced and want to encode as interlaced, the commandline has to be slightly adapted. Something like:

ffmpeg -i "your_source" -c:a aac -c:v libx264 -preset slow -level 40 -bluray-compat 1 -flags +ilme+ildct -crf 20 -pix_fmt yuv420p -vf "crop=684:560:12:0,scale=interl=1:w=960:h=720,pad=1280:720:-1:-1,setfield=tff,setdar=16/9" "16-9_i.mkv"

pause

or you deinterlace beforehand.

[benawhile]

Too many inserted frames. In addition to what Sharc properly suggested, put PC offline, disable anti-virus, terminate all processes running in background, capture to a dedicated hard drive or a fresh partition of the unique hard drive, set AmarecTV to "High" priority, do nothing while capturing, etc.

FAO Sharc as well. I have done what I can to cut down background apps but hasn't made slightest difference in either program.. Interestingly the stats box in OBS never goes above 6% cpu.Never shows In task manager the GPU is about 15%. And this is with the hardware option QSV H.264 selected in recording>video encoder. With x264 cpu usage is more like 8%.

This is while off line, Windows Update and Defender disabled. Saving to an external SSD drive. You can see the skips in the monitor view, even when not recording. It can't be the dazzle, because that works fine on Linux. There is a process priority setting which I changed from normal to idle and high, had no effect.

[lollo]

Saving to an external SSD drive

That's really a bad idea.

[benawhile]

Saving to an external SSD drive

That's really a bad idea.

In post #46 you said this "capture to a dedicated hard drive or a fresh partition of the unique hard drive", that was the best I could do, I only have one HDD partitioned in the laptop. Perhaps I misunderstood. Anyway, it was only a test. I wouldn't normally do that.

[lollo]

The best is capture to a second dedicated internal drive. If you have only one drive, you should have one dedicated partition for the capture different from the partition reserved for the OS. Never capture to an external drive.

[Sharc]

Never capture to an external drive.

I wouldn't say never. I really depends on your HW and system architecture. Probably not recommended for Laptops/Notebooks (I only use Desktop PC for capturing).

[benawhile]

I wouldn't say never. I really depends on your HW and system architecture. Probably not recommended for Laptops/Notebooks (I only use Desktop PC for capturing).

Sharc, I'm sorry but I spoke too quickly when I said the command line to add the bars "worked". The file that you posted to me named "16-9.mkv" does display unstretched on my TV with black bars as it should but although the command ran in the black boxand appeared to be doing something for about as long as it takes to play the ectual file, the end result file appeared unchanged and didn't display black bars on the TV.
Attached some screenshots of the process.
FWIW the process doesn't seem to create a copy of the file, I'm left with the same file except than in properties the creation time is updated to the time the command was run. Which I suppose is what I should expect.