Latest post Thu, Mar 26 2015 12:59 PM by cuervo. 7 replies.
Page 1 of 1 (8 items)
Sort Posts: Previous Next
  • Thu, Mar 19 2015 11:50 PM

    • awahlquist
    • Not Ranked
    • Joined on Thu, Mar 19 2015
    • Posts 1
    • Points 15

    DPX in 8.3.1

    The ability to have a 2K/4K project, then AMA link and export DPX is great progress, and could mean new faster workflows for finishing.  For the finishing purposes my chief question is always about bit-depth and rendering accuracy to keep the highest possible quality throughout.

    I've been testing DPX in and out of Avid and here is what I've found.

    10-bit DPX files are always forced to be Video range on AMA link-- there does not seem to be an option otherwise to interpret as Full range, which most other software uses Full range for DPX.  You can use a video to full transform, but that introduces bit-depth artifacts, since it calculates a squeeze to video range, and then an expansion to full range, so you lose color accuracy. 

    Is there a way Avid can allow 10-bit DPX to import full range please?  Or have the option in the Source Settings?

    In the 10-bit DPX export, if you select "video range" it will rescale your DPX back to full range, but like I said has less color accuracy because of the squeeze/expand process.  If you select "full range" it will export a full range dpx container with video range image inside.

    16-bit DPX does import in Full range naturally, and can then export back out as Full range. if you select "video" in the export window, it will leave it as is, full range data in a full range container.  If you export "full range" it will clip the whites and blacks as it expands what it assumed was video range out to full range scaling.

    So far to have the coveted perfect DPX-in DPX-out, you either accept that you'll have video range DPX's in 10-bit, or you can use 16 bit in and out.  I hope Avid will look at this and give us more options with the 10-bit to be in full range as well.

    Andrew Wahlquist

    Local Hero Post

    Filed under: , , ,
  • Fri, Mar 20 2015 12:18 AM In reply to

    • jef
    • Top 50 Contributor
    • Joined on Sun, Feb 26 2006
    • Maryland
    • Posts 3,407
    • Points 41,115

    Re: DPX in 8.3.1

    Thank you for this report.  I will try to double check your test soon.

    The now dead Avid DS did handle DPX levels correctly.  There is much knowledge and experience that Avid should be harvesting from that product, but I continue to be surprised that this does not happen.  I would be speculating if I gave my hunchs as to why this might be the case.

    Thanks for sharing.

    Jef

    Avid DS 11.0.2 R.I.P | MC "Well, it depends ..." mostly 8.10.0 but playing w 2018.11| OS 10.11.x - various MacPro Towers - home system MacPro... [view my complete system specs]

    _____________________________________________

    Jef Huey

    Senior Editor

    Old Stuff  http://vimeo.com/album/3037796

  • Tue, Mar 24 2015 2:30 AM In reply to

    • jef
    • Top 50 Contributor
    • Joined on Sun, Feb 26 2006
    • Maryland
    • Posts 3,407
    • Points 41,115

    Re: DPX in 8.3.1

    Ok, I tested and you seem to be correct.  This makes the whole DPX workflow very limited.

    I did some other testing and ran into a lot of questions about color management in DNx HR in general.  I am trying to get a grasp on what seems like a first generation workflow at this point.

    Jef

    Avid DS 11.0.2 R.I.P | MC "Well, it depends ..." mostly 8.10.0 but playing w 2018.11| OS 10.11.x - various MacPro Towers - home system MacPro... [view my complete system specs]

    _____________________________________________

    Jef Huey

    Senior Editor

    Old Stuff  http://vimeo.com/album/3037796

  • Tue, Mar 24 2015 3:15 AM In reply to

    Re: DPX in 8.3.1

    Rant

    In this digital age (no CRT monitors ) it stuns me that we are continually releasing "deliberately artificial" "NEW" standards to complicate / perpetuate the differences between computer and broadcast monitoring. IMO every step we take down this path increases the credibility of the redundant "cant do that because we need backward compatibility" lobby!! I believe it will also insure issues like this continue as the code writers may understand the differences but often (it seems) fail to understand the myriad of workflows we have developed to get around colourspace and gamma issues

    The majority of TV's sold for the last 12 months all want to be your internet monitor. IMO simple delivery output LUTs or $2.00 colourspace chip should be able to resolve any requirements for backward compatibility (like 709 broadcast delivery)

  • Wed, Mar 25 2015 2:36 PM In reply to

    Re: DPX in 8.3.1

    That's a very intesting study. I was about to suggest to a local post house to use MC as their finishing machine. 

    When you say you are getting full range out of the 16 bit, are you then using RGB color space? Have you tried P3 on the 10 bit DPX sequences?

    Mac Pro 8 core 2.4 Ghz (Middle 2010), 14 Gbs RAM, Matrox MXO2 Mini, GTX970 OSX v.10.10.1 AVID MC 8.3.1 [view my complete system specs]
  • Wed, Mar 25 2015 8:08 PM In reply to

    Re: DPX in 8.3.1

    Can confirm.  

     

    DPX files are acting as if a "full range to video levels" color adapter is being applied.  Howwever, no adapter is present in the source settings.  Manually adding a "video to full range" adapter will fix the issue, but it still results in a slight degrade in quality, as expected.  

    I cannot tell if the issue lies with MC not properly reading the DPX levels, or erronimously not reporting the added color adapter.  MC 8.3.1.  

    Home: 2012 rMBP 2.6ghz, 16GB RAM, OSX 10.10.5, MC 8.4.1 || Work: HP Z400, Win7 Professional, MC 6.5, ISIS/Interplay @danielfrome on twitter [view my complete system specs]

    Avid GoPro

  • Wed, Mar 25 2015 9:15 PM In reply to

    • jef
    • Top 50 Contributor
    • Joined on Sun, Feb 26 2006
    • Maryland
    • Posts 3,407
    • Points 41,115

    Re: DPX in 8.3.1

    Our tests of several color management issue in MC 8.3.1 are proving VERY confusing.  The help files are not very useful.  I would strongly suggest anybody planning a job integrating footage from outside products do a full beginning to end test.

    Jef

    Avid DS 11.0.2 R.I.P | MC "Well, it depends ..." mostly 8.10.0 but playing w 2018.11| OS 10.11.x - various MacPro Towers - home system MacPro... [view my complete system specs]

    _____________________________________________

    Jef Huey

    Senior Editor

    Old Stuff  http://vimeo.com/album/3037796

  • Thu, Mar 26 2015 12:59 PM In reply to

    • cuervo
    • Top 100 Contributor
    • Joined on Fri, May 2 2008
    • Santa Fe, NM
    • Posts 1,174
    • Points 15,595

    Re: DPX in 8.3.1

    I'm reading this thread with great interest. I've noticed other instances where AMA'd injests are remapped from full range to video levels with no way to disable this remapping. As you pointed out, going thru another remapping to full range introduces artifacts. I, sincerely, wish Avid would address this issue quickly, as this is just a huge stumbling block to v 8.3.

    SYS1:ASUS Z97, Haswell 4.0GHz CPU, 32GB RAM, Quadro 4200 + GTX1070, Thunderbolt II -DNxIO-FSI CM171 ///SYS2:ASUS Maximus Extreme V, Sandy Bridge 3.1GHz... [view my complete system specs]

    M-Power Independent Video and Film Services, Sony PMW-F5--Sony FS700U--Canon 7d--Odyssey 7Q

Page 1 of 1 (8 items)

© Copyright 2011 Avid Technology, Inc.  Terms of Use |  Privacy Policy |  Site Map |  Find a Reseller