How to match the AR of SD vs HD?

[takearushfan]

Hey all,
It's been a while since I had any idea how to do these things so I could use some help.
Attached are two shots, a SD (720x480) and an HD (1916x808). Can someone please look them over and advise how to properly blow up the SD one to match the HD shot?
I'd imagine cropping would be involved but yeah, I don't know.
Thanks
- J

[sanlyn]

How were the captures made? How did you get the original source video onto your computer? What is the frame rate of the original source? Was it taken from a DVD? A little short on info here.

IF this is a Hollywood movie, note that Hollywood doesn't make movies in a 16:9 aspect ratio. In n ay case, 1916x808 is non-compliant for BD or AVCHD disc and, further, you will not be satisfied with SD source resized to a more 1920x1080 -- which a 16:9 frame that does not accurately reflect the correct aspect ratio for a 1.85:1 or 2.35:1 Hollywood movie.

[jagabo]

You can get close simply by cropping the top and bottom black borders and resizing what's left to 1916x808. If you need more perfect results than that you'll have to spend a lot of time working out the details.

[takearushfan]

Sanlyn:
The SD and HD captures were both "copy output frame to clipboard" in VDubMod. The SD taken straight from the DVD's VOB. The HD version is an iTunes rip; no re-encoding... I used Requiem to directly strip the DRM. I then pasted them into Photoshop and saved as a bitmap. The HD version really is 1916x808, which makes me think they kind of "pre-cropped" it for streaming...? The DVD's frame-rate: 23.976. The HD frame-rate is the same. I didn't resize anything.

Jagabo:
The problem with cropping the top/bottom is that I can't seem to pinpoint where the borders truly end and the picture data begins. Even if zoomed in to an outrageous degree, the borders seem to melt into the picture :/

[poisondeathray]

You can start by using the same frame (these aren't the same frame)

It looks slightly warped, so it will be difficult to match perfectly

What is this for ? / Why are you doing this ?

[jagabo]

I agree they are different frames.

[takearushfan]

I'll start with being more careful and using matching frames.
This is basically just an experiment to see what kind of difference/improvement there is when taking clip A in SD then switching to the same clip in HD, within the same merged video clip.

[poisondeathray]

If we assume there was no camera motion between those frames, and you only want to get a "close" match; in RGB mode (you can't crop by non even numbers in YV12) :

Crop(1,55,-1,-60)
Spline36Resize(1916,808)

[jagabo]

I'll start with being more careful and using matching frames.
This is basically just an experiment to see what kind of difference/improvement there is when taking clip A in SD then switching to the same clip in HD, within the same merged video clip.

Then you don't really need pixel perfect scaling. And when you're working in YV12 video you have to copy by even numbers. And you'll have to control for rec.709 vs. rec.601 colors.

Use a script like this to compare:

hd=ImageSource("HD-1916-808.bmp")
sd=ImageSource("SD-720-480.bmp").Crop(1,55,-1,-60).Spline64Resize(1916,808)
Interleave(hd, sd)

[takearushfan]

Okay. Thanks. That did work well for a still image. Now, what if I'm trying to have a certain number of frames from clip A playback before switching to clip B's playback? Same idea, just not with a still image. Clip SD lasting for let's say 2 seconds, then switching to the HD's 2 second clip...?

[jagabo]

Interleave() works with videos. In fact, the earlier example works by opening two images as video clips. It's always frame by frame though. If you want 2 seconds of A and 2 seconds of B you can use Trim() to snip out a few seconds of each then append them:

video1 = WhateverSource("video1.ext").Trim(video1, 1000,1049) # 2 seconds of a 25 fps video
video2 = WhateverSource("video2.ext").Trim(video2, 1000,1049) # 2 seconds of another 25 fps video, doesn't have to be the same frame numbers
video1+video2 # append the clips

[takearushfan]

Thank you, by the way. Despite how long it's been, I feel it's rude not to come back and say thanks for showing me something that worked.
Much appreciated