6 thoughts on “Transcoding Anamorphic 2.8K ProRes

    • bradleyjandrew says:

      Hi Tony,

      Thanks for touching base. When I initially tackled this transcoding problem the original values specific worked perfectly to solve the black border issue, I used them on many jobs with no problems.

      It appears that something has changed either in the ARRI Image Processing or the way Resolve interprets it both when I compiled the assets for this post and over the past few weeks when I’ve been working.

      In the future when completing this transcode task please apply a scale of ‘1.023’ to the X and Y rather then the specified ‘1.059’. This will ensure a full frame anamorphic image with no black borders and no minor image cropping. I have verified this and confirmed that it works.

      Please let me know if you have any other issues!

      Regards
      Brad

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  1. andrew g says:

    Thanks so much for the detailed guide! I kinda got lost on the math, but you’re sure you need to re-size both the X & Y to get rid of the borders? Or should you just be stretching X? Seems to me that you shouldn’t need to do anything to the Y dimensions in an image that is just squeezed horizontally. But, after scaling up X & Y, it’s still a perfect 2:1 ratio?
    Thanks!!

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    • bradleyjandrew says:

      Hi Andrew,

      No worries at all, I’m glad that you found it helpful. You definitely need to resize both the X and the Y, if you just resize the X it will actually stretch the image slightly which would make it slightly distorted, proportions should be constrained when scaling up. I understand the point you are making but despite the black borders there is no way the images come out of the camera squashed or stretched. The native aspect ratio for the format discussed (Anamorphic ProRes 2.8K) is 2.66:1 which is usually cropped at the sides to make 2.39:1, so yes, if you scale up both X and Y you maintain that 2.66:1 Native Aspect Ratio.

      Thanks!

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  2. Chris says:

    Hi Andrew,

    Thanks for the timely walk through! We’re intending to use the camera original ProRes files to edit in Premiere and then take the finished edit to Resolve. From the looks of your workflow and applying it to Premiere, we just interpret the footage as 2:1 anamorphic and it will then be interpreted correctly? From my eyes it seems to be the case.

    Then it’s just a matter of scaling it in our sequence to fit? Like the other commenter I was also confused as to whether we should just be scaling the X axis.

    It looks like we’ll be editing it in a 2.39:1 sequence, so we will loose some of the image on either side anyway.

    Thanks Andrew!
    Chris

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    • bradleyjandrew says:

      Hi Chris,

      Thanks for reading and reaching out. Just for the record, my name is Brad, it often gets confused with my surname Andrew so all good!

      That sounds about right to me, if you’ve got fast enough drives and a decent system editing 2.8K ProRes natively in Premiere shouldn’t be a problem. As you say, if you shot anamorphic definitely run a 2x desqueeze and you should be good to go, your eyes will be the best judge. Just remember the native aspect ratio of disquieted 2.8K Anamorphic is 2.66:1, so if you framed for 2:39:1 you’ll need to zoom in 11.3% to ensure what you see in Premiere matches what you shot, then you’ll have left to right racking room for corrections. Or setup your sequence for 2.39:1 which is sounds like you have done.

      Keep in mind that the aspect ratio scaling mentioned above is different to the black border scaling. Different softwares handle the black borders differently. If you open the files in Quick View or Quicktime on Mac you won’t have black borders, but you will in Resolve. You’ll get different results if you playback in Silverstack, Premiere, VLC, etc. and it also depends on what version you are running. If cutting natively in Premiere and you don’t see any black borders then you shouldn’t need to scale to correct this issue.

      To understand the uniform scale for the black border you need to look at some specs. The camera shoots at ‘2880 x 2160’ but displays in the Quicktime Container at ‘2944 x 2160’, this indicates that we only need to scale the X Axis, but when you look at the desqueezed image in Resolve circles still look like circles, and I’m confident the black border is around the entire image despite not being able to see it as it blends with the slug of the 2:66:1 Aspect Ratio. There is no way that ARRI would record a squashed image out of camera and if you choose to scale only the X then you’ll be distorting your image which is certainly not desirable.

      I hope this helps!

      Regards
      Brad

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