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OT presenting non-square 601 as 4x3

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Paul Dougherty
OT presenting non-square 601 as 4x3
on Jun 1, 2015 at 7:58:02 pm

How to reliably make 720x486 interlace Qt "present" as 4x3 progressive?

I'm preparing to do some archival work to capture NTSC video from analog tape and create digital files. I'll do my capturing with an Avid MC which creates 601 interlace files that are 720x486 with rectangular pixels. I'll most likely transcode to make some 4x3 progressive deliverables (ProRes, mp4).

My question depends on the client. If I'm doing this for one that is a savvy video post client they know how and when to use 601 interlace Quicktimes. For less technical clients I fear these files will be mishandled. What I'm describing is a way for this Qt to play and at least look right, but it is a partial answer at best.

In Quicktime Player 7 I can adjust the Movie Property Settings to make the mov play (aka present) as 640x486 Display Size and check the deinterlace box. I do that, save the changes and it looks good in Qt 7. When I play that same modified Qt in the regular Quicktime Player (10.1 on a Mac) it is not longer 4x3 = fail.

In another forum someone said "Almost all modern audiovisual container formats have means to declare non-square aspect ratios so that 720x486 could be presented at 720/486, 4/3, 16/9 or whatever aspect ratio the presentation should use" Is there a more bulletproof way of achieving this?

Before I post again in that forum I want to a little more research, so would appreciate any input.

Thanks,

Paul


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Craig Seeman
Re: OT presenting non-square 601 as 4x3
on Jun 1, 2015 at 8:20:48 pm

QT7 and QT10 are pretty much unrelated technologies at this point. QT7 is basically EOL.
QT7 is based on QT Frameworks and QT 10 is based on AVFoundation. The don't handle frames or flags the same way.

I would target 640x480 and test in QT 10 and WMP 12. WMP 12 can play H.264 .mov files.
640x480 is a "universal" 4:3 Standard Def frame size.



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Paul Dougherty
Re: OT presenting non-square 601 as 4x3
on Jun 1, 2015 at 8:39:52 pm
Last Edited By Paul Dougherty on Jun 2, 2015 at 2:51:47 pm

Thanks Craig, got it. Where then, in what software app, would I set these playback specs (4x3 & deinterlace) with an eye towards them respected aka being adhered to in a modern player? I don't see anywhere to do that in Qt 10. Again these are real-time, on-the-fly playback parameters. (not changes made in a derivative copy)

Paul


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