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SD to HD - To Stretch or Not to Stretch


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Hiya folks.
In an effort to somehow ground myself in the past, so that I carry forward, I've been remastering some old standard def. 4x3 films. Though in that I'm left wondering about stretching the width of the images so that they fill a 720 frame. This of course makes the subjects look a tad fatter... though I wouldn't say it looks objectionable. I'm curious, could anyone make a case for leaving the image 4x3 for authenticities sake? Does the SD frame have it's own merit?

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And to export what about Frame Rate and Pixel Aspect Ratio? Somehow I'd like to ditch 29.97 for 23.976.

The original files are: Image Size: 720 x 480, Frame Rate: 29.97, Pixel Aspect Ratio: 0.9091

*Edit. I just read the Toutube/ Vimeo prefers square pixels.

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1 hour ago, User said:

And to export what about Frame Rate and Pixel Aspect Ratio? Somehow I'd like to ditch 29.97 for 23.976.

The original files are: Image Size: 720 x 480, Frame Rate: 29.97, Pixel Aspect Ratio: 0.9091

*Edit. I just read the Toutube/ Vimeo prefers square pixels.

From an academic point of view, what you are doing is essentially "digital curation" (well, a ghetto version).

You would want to preserve all of the "significant properties" of the digital objects and only "transform" the intended property, which in this case, is the resolution.

That means square pixel, HD with original 4:3 aspect ratio (960x720 or 1440x1080, depending on how good the upscaling algorithm is). The frame rate should also remain unchanged.

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15 minutes ago, androidlad said:

From an academic point of view, what you are doing is essentially "digital curation" (well, a ghetto version).

You would want to preserve all of the "significant properties" of the digital objects and only "transform" the intended property, which in this case, is the resolution.

That means square pixel, HD with original 4:3 aspect ratio (960x720 or 1440x1080, depending on how good the upscaling algorithm is). The frame rate should also remain unchanged.

I now like the idea of keeping things as original as possible. I'll go with your point on 960x720 and stick with 29.97. Thanks Androidlad!

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Ok I'm lost.
For comparison, I looked at a friends Vimeo page, he used the same 640x480 camera as I did. Here is the thing, when I click the streaming 'quality'  tab on his Vimeo page it says 480. And then when I click the tab to make the video full the screen, the image goes to the top of my screen with only some pillars on the side. On the other hand, after having exporting a 960x720 frame from my film via PPro and uploading to Vimeo, the image does not go to the top of my screen (using Quicktime or Vimeo) which I somehow thought it would with only some pillars on the sides.
Can someone @androidlad explain things? And suggest an easy to path forward that will keep the aspect ratio while allowing the frame to reach the top of the screen. Also, should I be using upscaling software instead of PPro? Any suggestions?

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I work with a lot of SD footage still and I never "stretch" it. I do, when mixing it with HD footage, upscale and crop sometimes but only if there's not a lot going on in the clip and the framing looks OK, like a talking head. I usually pillar box it if there's action going on. Depends on the project. 

If you're just remastering stuff I'd do it in it's native aspect ratio. If you're putting it on YouTube I'd probably upscale it just so you get that bump in bit rate, but definitely keep the 4:3 aspect ratio. 

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3 minutes ago, newfoundmass said:

I work with a lot of SD footage still and I never "stretch" it. I do, when mixing it with HD footage, upscale and crop sometimes but only if there's not a lot going on in the clip and the framing looks OK, like a talking head. I usually pillar box it if there's action going on. Depends on the project. 

If you're just remastering stuff I'd do it in it's native aspect ratio. If you're putting it on YouTube I'd probably upscale it just so you get that bump in bit rate, but definitely keep the 4:3 aspect ratio. 

Always appreciate the 'extra' insights amigo. Big thanks!

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31 minutes ago, androidlad said:

NTSC 720x480 with 0.9091 PAR with the padding removed is 704x480, then converted to square pixel results in 640x480.

Padding removed?

Can you simply walk me through this? I'd be curious to see the results?

*Edit. I'm in PPro.

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Alright. New remix complete and exported. Killer.
Of course, part of working with interlaced footage is deinterlacing and that means a serious loss of quality especially in that the footage is shot in those crazy sodium vapour lit streets way out there.
I've exported an interlaced file from PPro with the hope that I can run it through a 'quality' deinterlacer.
Anyone have a suggestion on how to pull the max out of this compromised tech?

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Massive thread on broadcast standards, 720x480 etc:
https://forum.videohelp.com/threads/312656-Can-someone-EXPLAIN-the-whole-720x480-thing-to-me/page2?s=6dcace21254ec014db1d6a13a87cefd6

Consumer 8k on the horizon, I'm headed back to 2002 ;)

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18 hours ago, User said:

Alright. New remix complete and exported. Killer.
Of course, part of working with interlaced footage is deinterlacing and that means a serious loss of quality especially in that the footage is shot in those crazy sodium vapour lit streets way out there.
I've exported an interlaced file from PPro with the hope that I can run it through a 'quality' deinterlacer.
Anyone have a suggestion on how to pull the max out of this compromised tech?

Handbrake/Vidcoder's decomb and Bob does a pretty solid job on most things. It's probably the easiest unless you're familiar with something like AviSynth. 

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5 minutes ago, newfoundmass said:

Handbrake/Vidcoder's decomb and Bob does a pretty solid job on most things. It's probably the easiest unless you're familiar with something like AviSynth. 

Well said Newfoundmass, thanks.
With the empty Chinese food boxes splashed out on the table, it was the last meeting of the NTSC designers late that Friday night. And you know what the last words that were said.... 'Fuck it'. ;)

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It should be noted that 720x480 is 1.5 to 1 , and 640x480 is 1.333 to 1. So converting from one to the other means black bars must appear somewhere if you don't stretch the original image.

I have converted some old SD interlaced footage in the PAL format. An some of it was widescreen PAL where the pixels are nowhere square ( can't remember the ratio ) but the result is a 16 by 9 image from SD which has ( in PAL ) 720 x 625.

I wanted to put my old footage ( family movies etc ) made on a DV recorder ( PAL) into a non interlaced ( ie progressive ) format which I felt would be more future proof. I tried various things , but in the end I just put the SD footage into an editor and set the output to be 1920x1080 ( progressive ) and kept the frame rate the same. Davinci Resolve will not accept interlaced video , so I used handbrake to do this conversion. This would result in a image which had black bars at the sides. I would then if necessary stretch the image so that it was as original . I would try and find a circular object in the image and make it round . I found that Davici Resolve was useful for this as it allowed the x to y ratio to be fine tuned. I would still have black bars at the sides but at least people did not look fat or thin. I don't know if any of this helps , but that is what I do.

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