Aspect Ratio / Resize Issue - Totally Lost

[JAJT]

I'm totally stumped on this.

I've tried asking and looking into it a few times around the web and somehow leave more confused than I was going in.

I'm trying to convert some old family home videos that were on VHS to an format that looks great and "just works" to give to various family members for Christmas.

I'm reading everywhere that the likely best method is to take the 720x480 (3:2) capture files I did and de-interlace and upscale them to a more modern display friendly format like 1920x1440 (4:3). That way if someone is trying to play them on a device with garbage upscaling ability, it's not a concern. When I do this, I get a result which is pretty clearly squished horizontally compared to the original captures.

To get the raw captures, I basically did this:

- S-VHS -> DVD Recorder -> IO-Data GV-USB2 capture device -> Virtual Dub (All in S-Video)
- Captured using virtualdub using Notelu's guide: https://www.youtube.com/watch?v=KdGDwNwmyVo
- Video compression in virtualdub set to UtVideo T2 YUV422 BT.601 VCM

Next, in virtualdub I added used these filters and settings:

1. Deinterlace:
- Double frame rate, top field first

2. Resize:
- Absolute (pixels): 1920 x 1440
- Aspect Ratio: Disabled
- Filter Mode: Precise bicubic (A=0.75)
- Interlaced unchecked
- Framing options: Do not letterbox or crop
- Code-friendly sizing: Do not adjust

3. Video Compression
- x264 8 bit - H.264/MPEG-4 AVC codec

This is the raw vs upscaled result (sorry for low res):


[Attachment 67833 - Click to enlarge]


The resized version looks squished horizontally compared to the original.
When playing both videos side by side I think the de-interlaced and upscaled version looks amazing - it's just the wrong shape.

I've been reading that it could do with pixel size differences and such but as much as that explanation makes sense I don't know what to "do" about it.
Is there any way I can get the upscaled result to maintain the same aspect ratio as the original capture so it doesn't look squished?

[jagabo]

You're upscaled image shows the near correct 4:3 frame size. The raw video is showing the video at 3:2 -- the 720x480 (3:2) frame wasn't adjusted for the aspect ratio.

The upscaled image is near-correct because analog caps should be cropped to 704x480 before upscaling to 1440x1080 (or any other 4:3 frame size).

[Bwaak]

I'm reading everywhere that the likely best method is to take the 720x480 (3:2)

It is not 3:2, it is about 1.36 See Pixel aspect ratio in Wikipedia.

The resized version looks squished horizontally compared to the original. When playing both videos side by side I think the de-interlaced and upscaled version looks amazing - it's just the wrong shape.

The original looks stretched because of incorrectly applied pixel aspect ratio of 1. Right click on a source video preview panel in VirtualDub and select pixel aspect ratio 10:11, and it will look just right.

The resulting video may be just a little squished if you did not crop the original video from 720x480 to 704x480 before resizing.

[DB83]

To expand (hopefully) on what jagabo states, that 720*480 capture should display at 640*480.

The resize/upscale should be referenced to the vertical and not the horizontal. So your correct upscale, including a AR flag to be certain, would be 1440*1080.

[ProWo]

You would have been better off capturing at 704x480.
Nevertheless, your upscaled video with 1920x1440 in 4:3 ratio is exactly like the original on the VHS tape.

The fact that it doesn't have the same AR as the capture doesn't mean anything.
For me, you should leave it at the AR 4:3 (1.33) that it has now.

If you still want to change it, then download clever-FFmpeg-GUI here: https://files.videohelp.com/u/292773/clever_ffmpeg_gui_newest_beta.zip

Load your 1920x1440 video, click main, click Change DAR and enter the desired value in both fields (e.g. 1.5, same as your capture), check both options and click Convert DAR.


[Attachment 67834 - Click to enlarge]

Then look at your new video and see if you like it better.

[DB83]

The simple fact is that few, if any, capture devices will capture at 704*480. Capture software will, mis-leadingly, make you believe that setting it to 704*480 (e.g vdub) gives you pure 704*480 yet actually gives you a resized 720*480 (which is what practically all devices natively output). And the same goes for a more logical 640*480

And, personally, I have never been bothered by the minor difference between 720*480 (or the PAL version ie 720*576) to 704* especially when those 16 pixels are not equal on either side. And 640*480 still remains the true output regardless.

[Cornucopia]

1st, the standard 4:3 usage in HD is 1440x1080, not 1920x1440. While 1920x1440 is ostensibly 4:3 also, if being presented on an HD display, it would have to stretch/squeeze or crop, etc., while a 1440x1080 would show full screen 4:3 with pillarbars, as you would expect.

2nd, the behind the scenes truth is that pixels in use in most monitors are all the same shape. But the sample points they are based on may have different aspect ratios, even though the samples don't really have any dimension, they are points.

However, note you said your source was 704x480 (3:2). It's NOT. It is 720x480 (4:3), because all SD captures (e.g. from vhs, etc) use non-square sample/pixel ARs. Of course, since you used a formula that ignore original AR and was just going for 4:3 with square pixel , that shouldn't matter. But you should recognize that, because under the hood it must be taken into consideration.


Scott

[lollo]

You would have been better off capturing at 704x480.

Not an option and not technically correct: http://www.arachnotron.nl/videocap/doc/Karl_cap_v1_en.pdf

[ProWo]

You would have been better off capturing at 704x480.

Not an option and not technically correct: http://www.arachnotron.nl/videocap/doc/Karl_cap_v1_en.pdf

I meant cropping to 704x480 prior to upscale.

[lollo]

I meant cropping to 704x480 prior tu upscale.

That's absolutely correct

[Bwaak]

1st, the standard 4:3 usage in HD is 1440x1080, not 1920x1440.

Technically, broadcast HD is always 16:9.

However, note you said your source was 704x480 (3:2).

Did he? He wrote, "I'm reading everywhere that the likely best method is to take the 720x480 (3:2)".

It's NOT. It is 720x480 (4:3)

(720 * 4/3) / 704 = 1. ̅36̅

[Cornucopia]

Op hasn't said anything about broadcasting this, so that's not really an issue. And the option I mentioned is a very real and viable option for HD with most players.

I had originally written 720, but the at some point the op had 704 and I corrected mine to accommodate when I noticed mine didn't match, but that ended up not being necessary since it says 720 now.

Regardless, most of us here understand the very minor difference between 720 and 704 and what should be done to correct, and whether it really is necessary to do a correction or not. I would venture that most cannot visually alone discern a difference, unless they are placed on top of each other, so that decision is personal preference. What IS a noticeable difference is assuming 3:2 or 5:4 vs 4:3.

Scott

[Alwyn]

While 1920x1440 is ostensibly 4:3 also, if being presented on an HD display, it would have to stretch/squeeze or crop, etc.

I do a lot of 1920x1440 4:3 (for You Tube VP 9 coding). It displays exactly as any other 4:3 video: pillarboxed with no cropping/stretching/squeezing on "HD" (that is, 16:9) TVs and monitors.

[Bwaak]

Op hasn't said anything about broadcasting this, so that's not really an issue.

Sure. Why 1920x1440 is an issue then? I mean, I find this excessive, but who am I to judge.

Regardless, most of us here understand the very minor difference between 720 and 704 and what should be done to correct, and whether it really is necessary to do a correction or not.

No doubt. But does JAJT understand this difference? I think the reason for them asking for advice was that they did not.

[Alwyn]

Easy way to check: use a ruler or tape measure on the processed image on your screen. It's 1.34 (close enough to 1.33333333 or 4:3, which is what it should be).

Given my extensive knowledge of foldup chairs () the raw capture chair on the right does look a bit wide to me; the processed capture chair looks more natural.

[dellsam34]

Sure. Why 1920x1440 is an issue then? I mean, I find this excessive, but who am I to judge.

HD 4:3 is 1440x1080, An HD monitor with "Just Scan" feature does not have to do anything to display it. 1920x1440 is a bastard resolution, A HD monitor has to resize it and a UHD monitor has to resize it, It's only good for YouTube if you want the VP9 codec.

[Bwaak]

1920x1440 is a bastard resolution

This is a noble moniker for QHD resolution, thanks for the information.

[lollo]

HD 4:3 is 1440x1080, An HD monitor with "Just Scan" feature does not have to do anything to display it. 1920x1440 is a bastard resolution, A HD monitor has to resize it and a UHD monitor has to resize it, It's only good for YouTube if you want the VP9 codec.

+1

Apparently some people love lossy resizing

[Alwyn]

A HD monitor has to resize it and a UHD monitor has to resize it

This is the case with any video on any display. What's the big deal? Not in my decades of watching various sizes of videos on various sizes of screens have I ever had a problem with a screen "having to do something" to show the video.

[lollo]

This is the case with any video on any display.

Only if you love lossy (and useless) resizing

[dellsam34]

This is the case with any video on any display. What's the big deal? Not in my decades of watching various sizes of videos on various sizes of screens have I ever had a problem with a screen "having to do something" to show the video.

It is not the case with any video on any display, No one said anything about having a problem to display a video, We are talking about resizing vs just scan.