Keep 720x480 resolution or scale to 720x540?

[Wallabee19]

I've digitized my families old Video8/Hi8 tapes into a raw capture of 720x480 @ 29.97i and 4:2:2 chroma subsampling. I'm then processing this footage using AviSynth (deinterlacing/denoising/color correction/etc).

I also crop out the black bars on the side and also the head switching noise on the bottom. I then use AddBorders() after restoration filters to add them back to get back to the 720x480 resolution.

I am encoding the final videos using AV1 and they are intended to be played back on a PC (VLC, mpv, etc...) and I also plan on putting them on a USB Stick for my family to watch through a media box (Onn 4K Pro or another box that supports AV1 Decoding) that is connected to their TV.

My question is, should I simply leave the 720x480 resolution and simply mark the container (mkv) as 4:3 DAR and leave the pixels non-square? Or is it better to resize to a native 4:3 resolution of 720x540 with square pixels?

My current plan is to simply leave it as 720x480 (4:3 DAR, 8:9 SAR/PAR), and let the media player handle scaling to the container DAR. Unless there is a reason for my playback scenario that I should be resizing?

And one last bonus question. Is there any reason I should be changing the colorspace from BT.601 to BT.709? I plan on just tagging the container/bitstream colorspace/transfer/primaries as BT.601, and leaving it up to the media player to respect that. I think this is fine to do if I'm not upscaling to any sort of HD resolution? I don't plan on putting them on YouTube or anything. They will likely always be played through VLC (probably both on PC and Onn 4K Pro).

Thanks!

[lollo]

My question is, should I simply leave the 720x480 resolution and simply mark the container (mkv) as 4:3 DAR and leave the pixels non-square? Or is it better to resize to a native 4:3 resolution of 720x540 with square pixels?

The first, because you avoid a useless resizing.
If you want to be more accurate you should crop to 704x480 rather than 720x480, because Rec. 601 specification.
(You could also crop more and specify the SAR, but that's another story)

My current plan is to simply leave it as 720x480 (4:3 DAR, 8:9 SAR/PAR), and let the media player handle scaling to the container DAR. Unless there is a reason for my playback scenario that I should be resizing?

There are no reasons to resize, except if you want to upscale for whatever reason.

And one last bonus question. Is there any reason I should be changing the colorspace from BT.601 to BT.709?

No reasons, you change colorspace from 601 to 709 when you create a HD frame (i.e. 1440x1080 or 1920x1080).

[rgr]

I then use AddBorders() after restoration filters to add them back to get back to the 720x480 resolution.

I don't see the point in adding black margins. It's better to crop to the image size, of course preserving PAR (aka SAR). DAR will be what it is, and the image still will be narrow on current TVs/monitors.

My question is, should I simply leave the 720x480 resolution and simply mark the container (mkv) as 4:3 DAR and leave the pixels non-square? Or is it better to resize to a native 4:3 resolution of 720x540 with square pixels?

If you want to share with others, the mp4 format is more universal.

My current plan is to simply leave it as 720x480 (4:3 DAR, 8:9 SAR/PAR), and let the media player handle scaling to the container DAR. Unless there is a reason for my playback scenario that I should be resizing?

Resizing is completely unnecessary.

And one last bonus question. Is there any reason I should be changing the colorspace from BT.601 to BT.709? I plan on just tagging the container/bitstream colorspace/transfer/primaries as BT.601, and leaving it up to the media player to respect that. I think this is fine to do if I'm not upscaling to any sort of HD resolution? I don't plan on putting them on YouTube or anything. They will likely always be played through VLC (probably both on PC and Onn 4K Pro).

In principle there is no need, but for example I convert intermedially to RGB, so I do the final conversion to BT709. Of course, when using BT709 you have to indicate this in the metadata.

[hello_hello]

I think it's more likely for 10:11 to be the correct PAR, rather than 8:9.
https://forum.doom9.org/showthread.php?p=1058927

I wouldn't bother adding borders myself. I'd just crop the crud and set the appropriate PAR. Although I've never been worried about a little resizing. You could try the CropResize function in my signature. It'll at least make the borders as even as possible (centering the picture). I've applied a cropping of Crop(10,2,-12,-10), just as an example.

Source:


[Attachment 82642 - Click to enlarge]

No Resizing with borders:
CropResize(720,480, 10,2,-12,-10, NoResize=true, InSAR=10.0/11.0, Borders=true, Info=true)


[Attachment 82643 - Click to enlarge]

No resizing without borders:
CropResize(0,0, 10,2,-12,-10, NoResize=true, InSAR=10.0/11.0, Info=true)


[Attachment 82645 - Click to enlarge]

Resizing back to 720x480 with tiny borders:
CropResize(720,480, 10,2,-12,-10, InSAR=10.0/11.0, OutSAR=10.0/11.0, Borders=true, Info=true)


[Attachment 82644 - Click to enlarge]

Resizing back to 720x480 without borders (crops a little extra picture instead):
CropResize(720,480, 10,2,-12,-10, InSAR=10.0/11.0, OutSAR=10.0/11.0, Info=true)


[Attachment 82646 - Click to enlarge]

Resizing to 736x540 (a resolution requiring very little extra cropping in this case):
CropResize(736,540, 10,2,-12,-10, InSAR=10.0/11.0, Info=true)


[Attachment 82647 - Click to enlarge]