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Best way to handle ama sd pixel aspect ratio issues

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Kell Smith
Best way to handle ama sd pixel aspect ratio issues
on Dec 27, 2017 at 5:48:47 am
Last Edited By Kell Smith on Dec 27, 2017 at 1:58:51 pm

I have a 720p project and am trying to figure out the best way to handle sd AMA'd clips when it comes to aspect ratio.
The clips are weird dimensions - 716x480, 712x478, 710x480, 702x480 and more. I think there are a few 720x480 ones in there somewhere. They have all come in as 'stretched." Most of the listings in the "image aspect ratio" column are 1:32:1 and 1:33:1. Pixel aspect ratios generally are running .889, .909, etc. This isn't Avid weirdness, as far as I am aware this reflects the original files which are mostly Quicktimes - mp4, m4v, etc.
There is also HD material in this project, so the overall project has been sized 1280x720.

When changing the reformat column to pillarbox/letterbox those numbers don't change.

Output will be primarily DVD, and possibly some digital files.

What is the best way to fix these aspect ratios? Some of these are already edited so if possible I would prefer to fix them in the bin and update the sequence rather than adding an effect. thx


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Pat Horridge
Re: Best way to handle ama sd pixel aspect ratio issues
on Dec 28, 2017 at 8:40:38 am

Frame flex should solve it but you may have to manually adjust them.

Pat Horridge
Broadcast & Post Consultant, Trainer, Avid Certified Instructor
Free online Tutorials at VET digital media academy online http://vimeo.com/channels/752951
pat@vet.co.uk



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Kell Smith
Re: Best way to handle ama sd pixel aspect ratio issues
on Dec 28, 2017 at 2:24:28 pm

I assume you mean in the bin columns, is that correct?

So in the Image Aspect column they are various settings, 4x3, 1.50:1, 1:33:1 etc. When changing those, you should be shooting for as close to 1 in the pixel aspect column as possible?


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Kell Smith
Re: Best way to handle ama sd pixel aspect ratio issues
on Dec 28, 2017 at 3:02:35 pm

I thought I knew this but am apparently still unclear.


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Dave LaRonde
Re: Best way to handle ama sd pixel aspect ratio issues
on Dec 28, 2017 at 4:50:41 pm
Last Edited By Dave LaRonde on Dec 28, 2017 at 4:57:06 pm

We don't know the provenance of this video, so there's no good answer. The originals could be 720x486, 720x480, perhaps even 720x576. They're all originally 4x3 video, but different pixel aspect ratios to get to a 4x3 screen aspect ratio.

But if the video's been re-rendered by someone who didn't know what they were doing, the original pixel aspect ratio may have been altered. Hence the need to know the provenance.

Dave LaRonde
Promotion Producer
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA


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Kell Smith
Re: Best way to handle ama sd pixel aspect ratio issues
on Dec 28, 2017 at 6:45:47 pm
Last Edited By Kell Smith on Dec 28, 2017 at 11:46:34 pm

Thank you Dave,
Yes that's a good point.

I don't know the original details. These files were given to me on a drive, ripped either from DVDs by another editor or transferred from the originals.

Some of them were ripped directly from the VOB files in Mpeg Streamclip and transcoded to quicktimes, that I know, and those are 720x480, but the vast majority of them just given to me as mp4s, and m4vs with these sizes. I am not sure what their journey was to arrive at that point. Given that some go back to the late 90s, they were probably just transferred at some point in time.

Given that info, if someone had given these to you and you had to correct the aspect ratio in Avid (in the bin not the timeline preferably), what would be your approach?

I have one right now that the source was h.264 631x478, it AMA'd into Avid at 710x478, sd 30i ntsc, image aspect ratio 1.32:1, which I now have on pillarbox, PAR is .889. Project is 720p at present. To my eye it looks squished.



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