Thursday, February 23, 2023

Re: [Avid-L2] Is DNxHR only Progressive?

John,
I see reversed field order on news feeds all the time. It has a weird reverse judder to it. I've tried AE and re-xporting to progressive without much luck. Now I'm working in Edius so I have different options. I have found once the error is baked in it seems to not be removable. I come across the same problem with cellphone footage with weird cadences due to odd shutter and frame rates. By the time I get that footage in my feeds and bins I'm screwed, throw my hands up and move on. MMJ's who don't set up cameras or know how to is another beef I have. Since I switched my news camera to 29.97P I have a lot less issues with temporal errors and matching GoPro and Iphone material. In this day and age Interlace should be long dead and buried. Now NTSC 525 file is a different story.

TMcD
Fox8 WVUE
Photog/Editor/Magic Sorcerer

On Feb 23, 2023, at 8:51 PM, John Moore <bigfish@pacbell.net> wrote:


I got some archival footage from AP that came as 29.97Interlace XDCam 422.  Given we are delivering in UHD I have been taking HD sources, virtually all of which have been progressive, and transcoding to DNxHRHQX then transcoding to DNxHRLB for offline.  I want to maintain my interlace adjustment options and I found there is no UHD 29_97 interlace option in the format.  I left the project in 59.94i and consolidated and the resulting clip shows up as interlace.  Then when I went to transcode for offline at DNxHRLB clicking maintain clips frame rate the resulting clips are listed in the bin as progressive.  I resorted to just doing a second consolidation to the offline media drive to maintain the interlace status in the bin. 

Does this mean that all DNxHR media is progressive and no way for it to be interlaced?  I'll continue to explore to see if the clips that were bin labeled as progressive are in fact progressive.

I have found that one of the clips has the field order reversed when I step through field by field.  I tried a traditional import to DNX220X but it still comes in as XDCam 50 with wrong field order.  When I say field order it is temporally field 2 is before field 1.  I tried toggling the traditional import between odd/upper field first and even/lower field first but the resulting clips still show the temporally reversed field order.  I'm thinking because it seems to force the import to XDCam 50 and not DNxHD 220X the odd or even field choice may be being bypassed.

So is there a way in After Effects or some other software to reverse the temporal field order of an interlaced clip.  I recall Bouke had built odd and even field mattes for using matted keys and slipping one track one frame that would end up reversing the temporal field order but that was in SD land.  Only one out of the 4 clips has this issue and I'm betting it's some workflow issue where AP is baking the video essence in XDCam wrapper.  Very annoying.

John Moore Barking Trout Productions Studio City, CA bigfish@pacbell.net

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