Resizing Interlaced Video

[jagabo]

Personally, I'd downscale to 1280x720 rather than upscale to 1920x1080. Even the original broadcast wasnt't very sharp so the downscale isn't going to hurt it.

The vast majority of the footage I have is from the live broadcast, so I'd much rather leave that alone at 1080i and edit the first little bit to match.

But it's a very fuzzy 1080i. You won't lose anything by downscaling to 720p60, just get a smaller file with better image quality (if you use QTGMC). ESPN natively broadcasts in 720p. So your 1080i video has been upscaled.

[koberulz]

It's ESPN Australia, not ESPN in the US, and the footage originated with Altitude (I think), as in the US it wouldn't have been broadcast outside of Colorado. So guessing at the original resolution is a bit more complicated.

I'd rather just stick with mucking around with the first 20 minutes, rather than the full two hours, which is doubtless quicker. Not to mention my menus are all designed for 1920x1080.

[jagabo]

ok cropping the first post image I get 1802x972 for the real footage, that means cropping left and right is about (1920-1802)/2 ~ 60 pixels, not 88, not 96 I don't get that

After removing the black borders you are left with 1802x972 -- that's a ~1.85:1 aspect ratio. The OP wants a 16:9 aspect ratio to match his other video. A 16:9 frame with a height of 972 pixels is 972 * 16 / 9 = 1728 pixels wide. So he as to crop more of the width, a total of 1920 - 1728 = 192 pixels. I cropped 96 pixels off each side. The remaining 1728x972 (16:9) video can then be enlarged to 1920x1080 or reduced to 1280x720, retaining the 16:9 aspect ratio and without distorting the picture.

[koberulz]

letterboxed (picture registered with the original broadcast for A/B flipping, not centered):


[Attachment 46939 - Click to enlarge]

This is probably the least-bad option, for mine. What are the numbers and how did you get to them?

[jagabo]

letterboxed (picture registered with the original broadcast for A/B flipping, not centered):


[Attachment 46939 - Click to enlarge]

This is probably the least-bad option, for mine. What are the numbers and how did you get to them?

First I cropped away the black borders and the ticker. That left an 1802x972 frame. To upscale that proportionally to 1920 pixels wide you need to upscale the height to 972 * 1920 / 1802 ~= 1036. Then add letterbox bars to fill out the 1080 line frame, 1080 - 1036 = 44 lines total, say 20 top 24 bottom.

The crop and resize can be done in one operation: Spline36Resize(1920, 1036, 60, 0, 1802, 972).

[koberulz]

Do I need to run QTGMC before that, and then a weave afterward?

I'm not sure where the "972*1920/1802" comes from?

[jagabo]

Do I need to run QTGMC before that, and then a weave afterward?

For simplicity's sake I'd run QTGMC before the crop (otherwise you have to be careful of mod4 restrictions) and resize and addborders, then re-interlace.

I'm not sure where the "972*1920/1802" comes from?

Since we are working with square pixels we want to scale the height by the same multiplier as the width:

NewHeight = OldHeight * NewWidth / OldWidth.

[_Al_]

...., instead to add some black bars at the bottom and top after resize, he posted real image so it might be doable, .....

First I cropped away the black borders and the ticker. That left an 1802x972 frame. To upscale that proportionally to 1920 pixels wide you need to upscale the height to 972 * 1920 / 1802 ~= 1036. Then add letterbox bars to fill out the 1080 line frame, 1080 - 1036 = 44 lines total, say 20 top 24 bottom.

The crop and resize can be done in one operation: Spline36Resize(1920, 1036, 60, 0, 1802, 972).

ok, thanks, this is what I was asking about, calling it that "math", also that was what Bernix was perhaps aiming for , trying to avoid that chunk-sum cut from left and right