Latest post Fri, Feb 8 2019 3:32 PM by Benjamin von Cramon. 9 replies.
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  • Mon, Feb 4 2019 7:22 PM

    Workflow for both RGB and Rec709 output

    I'm clear how to manage digital assets from source to output for NTSC monitors, also for electronic distribution, am getting tripped up on the case of needing both. For RGB monitors, if I output graphics that come from 0-255 and preserve that with output from After Effects in RGB, then if I use "don't modify, treat as legal range" when importing to Avid and Keep as legal range on export, I will have not changed anything in the 0-255 range in and back out, good to go for RGB monitors. If that project, however, includes video footage recorded in Rec709, also imported with "don't modify, treat as legal range", then I'd think I'd want to use expand to full range to avoid washed out levels in the video, but what will that do to the RGB sources in that project?, expand them from 0-255 to something higher?

    And if this same project also needs to be output for display on NTSC monitors, TVs, will I need to output those RGB sources referred to above from After Effects over again as Rec709, then let them import to Avid with "don't modify, treat as legal range", now matching the 16-235 of the imported Rec709 video material, both output with "Keep as legal range"? That seems clunky to have to output twice and replace the various edits in the Avid. Thanks for advising.

     

    Benjy

    www.photo2topo.com

    Symphony 6.0.0 running on Lion 7.0.4, Mac Pro 8-core, 16 GB RAM, SSD startup and 3 Raid 0 SSDs backed up to external devoted to S3D projects, realtime... [view my complete system specs]
  • Mon, Feb 4 2019 8:26 PM In reply to

    Re: Workflow for both RGB and Rec709 output

    You should make everything legal inside MC, then expand to 0-255 upon export. Filler, Title white, FadeToWhite etc are all legal. 

    If your graphics are 0-255, either scale them to legal upon import or using a color correction inside MC.

     

    Indeed, if you import a 0-255 source maintaining its full range levels, then export from MC with “expand to 0-255), anything undee 16 will be black crushed and anything over 235 will be white clipped. So you will lose details in the blacks and the whites.

     

    Media Composer /w Symphony option | PT-HD | Win7Pro64 HP | OSX MBP | ISIS5000 | Nitris DX | Artist Mix & Transport & Color | AJA T-Tap | Decklink... [view my complete system specs]
  • Mon, Feb 4 2019 9:04 PM In reply to

    Re: Workflow for both RGB and Rec709 output

    Thank you, Job. I sure hope not to complicate things, but to be sure I'm tracking you correctly and to compare against my own experience, I need to raise a question based on a recent project involving some image sequences created in a game engine, so 0-255 at source. In After Effects when I output these in DNxHD codec using Rec709, and imported to Avid "don't modify, treat as legal", I was never able to get anything other than crushed blacks using either "Keep as Legal Range" or "Scale from Legal to Fulle Range" when viewing on a computer monitor (vimeo upload). It was only after exporting from AE using RGB, not modifying on import to MC, and outputting Keep as Legal Range that on a computer monitor I finally saw the shadow detail I expected to see in these scenes that were relying on lots of dark subject matter. I reasoned this was so because 1) began with 0-255, 2) preserved RGB on export from AE, 3) RBG material not modified on import to MC, and 4) MC output not modified either.

    If I'm hearing you right, had I exported from AE using Rec709 levels, not modified and treated as legal in MC, then expanded to full range on export I should have preserved the shadow detail. The luminance levels that previously fit inside 0-255 would have been compressed into the smaller 16-235, but then expanded once more on export back to 0-255. Yes? When I tried that, I saw crushed blacks. Note, 0-255 has more (36) levels of grey than 16-235, so wouldn't this imply I'm performing a lossy compression on luminance going from RGB to Rec709? The subject matter in these videos features lots of subtleties in the shadows, which is how I noticed the loss, know I'm not dreaming about that part. Might the compression from RGB to Rec709 explain this loss of shadow detail? 

    Big thanks, know it's a bit tedious.

    Symphony 6.0.0 running on Lion 7.0.4, Mac Pro 8-core, 16 GB RAM, SSD startup and 3 Raid 0 SSDs backed up to external devoted to S3D projects, realtime... [view my complete system specs]
  • Mon, Feb 4 2019 9:32 PM In reply to

    Re: Workflow for both RGB and Rec709 output

    No, these are two different things.

    First know that DNxHD is a broadcast codec, and it assumes content to be Rec709 legal. It can hold 0-255 for headroom and footroom, but it is not a codec that was designed to hold other color spaces or luminance ranges.

    When you are exporting to DNxHD Quicktimes in After Effects, the RGB/709 buttons work differently than you appear tp assume. When you tick the 709 box during exort from AE, you are telling the QT encoder that your source (your AE project) is legal and should not be changed (which results in illegal levels being maintained. If you tick the RGB box during export in AE, you are telling the QT encoder that your source is 0-255 and it needs to compress luminance levels to 16-235 during the encoding.

    If you exported from AE using the RGB button, the QT encoder has converted to legal levels and you should import into MC as 709/maintain.

    If you exported rrom AE using the 709 button, the QT encoder has not altered the levels, and you should import into MC wihnthe RGB/remap option.

    Media Composer /w Symphony option | PT-HD | Win7Pro64 HP | OSX MBP | ISIS5000 | Nitris DX | Artist Mix & Transport & Color | AJA T-Tap | Decklink... [view my complete system specs]
  • Tue, Feb 5 2019 12:36 AM In reply to

    Re: Workflow for both RGB and Rec709 output

    Gosh, thanks for clearing that up, nice job explaining, much appreciated. If I'm following, RGB source content in AE rendered with RBG option gets compressed to Rec709, should be imported as such, so "Treat as Legal, do not modify" keeps it as Rec 709 in Avid. If that content now shares the same luminance levels with live-action video encoded to DNxHD, one export to NTSC monitors would simply use "Keep as Legal", another export for online use would use "expand to Full Range", yes?

    If as I say (and if my memory serves me) I exported correctly from AE ticking RBG (never mind my wrong assumption), and then exported from Avid staying in Rec709 with Keep as Legal Range, then should I have seen really flat video levels online, washed out blacks on suppressed white point? I'll need to check again, but seems it looked correct. You have no comparison, and monitors can lie, but if you wouldn't mind looking at this animation, should be pretty obvious if black and white point are off. This was definitely done leaving AE in RGB, imported to MC not modified (in Rec709), and left MC unmodified. 

    You're really kind to take the time to explain this, big thanks.

    Symphony 6.0.0 running on Lion 7.0.4, Mac Pro 8-core, 16 GB RAM, SSD startup and 3 Raid 0 SSDs backed up to external devoted to S3D projects, realtime... [view my complete system specs]
  • Tue, Feb 5 2019 4:30 AM In reply to

    Re: Workflow for both RGB and Rec709 output

    Benjamin von Cramon:

    Gosh, thanks for clearing that up, nice job explaining, much appreciated. If I'm following, RGB source content in AE rendered with RBG option gets compressed to Rec709, should be imported as such, so "Treat as Legal, do not modify" keeps it as Rec 709 in Avid. If that content now shares the same luminance levels with live-action video encoded to DNxHD, one export to NTSC monitors would simply use "Keep as Legal", another export for online use would use "expand to Full Range", yes?

    Yes.

    If as I say (and if my memory serves me) I exported correctly from AE ticking RBG (never mind my wrong assumption), and then exported from Avid staying in Rec709 with Keep as Legal Range, then should I have seen really flat video levels online, washed out blacks on suppressed white point? I'll need to check again, but seems it looked correct. You have no comparison, and monitors can lie, but if you wouldn't mind looking at this animation, should be pretty obvious if black and white point are off. This was definitely done leaving AE in RGB, imported to MC not modified (in Rec709), and left MC unmodified. 

    You're really kind to take the time to explain this, big thanks.

     

    When in doubt about your monitors, check the Waveform monitor in color correction mode.

    Media Composer /w Symphony option | PT-HD | Win7Pro64 HP | OSX MBP | ISIS5000 | Nitris DX | Artist Mix & Transport & Color | AJA T-Tap | Decklink... [view my complete system specs]
  • Tue, Feb 5 2019 4:20 PM In reply to

    Re: Workflow for both RGB and Rec709 output

    Thanks, I'll bring my output as described back in to Avid and check on the waveform monitor, report back. Seems clear now.

    Symphony 6.0.0 running on Lion 7.0.4, Mac Pro 8-core, 16 GB RAM, SSD startup and 3 Raid 0 SSDs backed up to external devoted to S3D projects, realtime... [view my complete system specs]
  • Fri, Feb 8 2019 2:38 AM In reply to

    • Hoh
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    Re: Workflow for both RGB and Rec709 output

    Thanks Job.  I've been trying to figure out this issue (as most of my stuff has been going online) for the past 8 years or so, and is one of the reasons I have moved certain projects over to Premiere Pro for online use.  Now I can feel better about getting real colors and true contrast in my online videos.  Thanks! - Darin 

    (1): Media Composer 2018.12 ∙ Windows 7 Pro ∙ HP Z840 Xeon E5-2620 v3 2.4GHz ∙ 64GB RAM HP Samsung DDR4 2133 ∙ NVIDIA Quadro K4200 385.69 ∙ Matrox Mojito... [view my complete system specs]
  • Fri, Feb 8 2019 2:51 AM In reply to

    • Hoh
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    Re: Workflow for both RGB and Rec709 output

    This is helpful too https://www.youtube.com/watch?v=_oYxKN3W6VA 

    youtube(dot)com/watch?v=_oYxKN3W6VA 

     

    Hoh:

    Thanks Job.  I've been trying to figure out this issue (as most of my stuff has been going online) for the past 8 years or so, and is one of the reasons I have moved certain projects over to Premiere Pro for online use.  Now I can feel better about getting real colors and true contrast in my online videos.  Thanks! - Darin 

     

    (1): Media Composer 2018.12 ∙ Windows 7 Pro ∙ HP Z840 Xeon E5-2620 v3 2.4GHz ∙ 64GB RAM HP Samsung DDR4 2133 ∙ NVIDIA Quadro K4200 385.69 ∙ Matrox Mojito... [view my complete system specs]
  • Fri, Feb 8 2019 3:32 PM In reply to

    Re: Workflow for both RGB and Rec709 output

    Helpful, indeed. Tanks, Darin.

    Benjy

    www.photo2topo.com

    Symphony 6.0.0 running on Lion 7.0.4, Mac Pro 8-core, 16 GB RAM, SSD startup and 3 Raid 0 SSDs backed up to external devoted to S3D projects, realtime... [view my complete system specs]
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