Latest post Sat, Jun 24 2017 8:40 PM by S.Clements. 25 replies.
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  • Wed, Jun 21 2017 11:46 PM

    • S.Clements
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    Difference between Avid and Resolve Transcodes of same Arri ProRes 4444 QTs

    Hi, Guys.

         I am supposed to transcode rushes in Ressolve, rather than Avid.  I am new to the workflow, but have followed many tutorials and read much advice.  However, when I compare the Ressolve transcodes to the Avid transcodes (made by AMA linking Arri ProRes 4444 files) the Resolve transcodes are lighter.  This is not good.  They should look exactly the same.

         Someone suggested I could export the embedded LUT from the ProRes files with the Arri Color Tool and use it in Resolve, which I'm pretty sure I did correctly.  While it darkened the footage a bit more than Resolve's built-in rec 709 LUT, the transcodes are still lighter than Avid's.

         Does anyone have any idea what could be causing the difference?  I have tried every permutation I can think of and am not really into all this color science stuff.

    Avid Media Composer 8.3.1 Macbook Pro (Retina, 15-inch, Mid 2014) 2.8 GHz Intel Core i7, 16GB Ram Mac, OS 10.10.2 [view my complete system specs]
  • Thu, Jun 22 2017 12:27 AM In reply to

    Re: Difference between Avid and Resolve Transcodes of same Arri ProRes 4444 QTs

    What format are the original Arri files?

    What format are the transcodes?

    What OS are you using?

    And what media player are you using to view the transcodes?

     

    "When I spent 60k on a discreet edit digisuite system 10 years ago someone came up to me to offer fcp 2, I said it was a scam too." -Ric

  • Thu, Jun 22 2017 12:37 AM In reply to

    • S.Clements
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    Re: Difference between Avid and Resolve Transcodes of same Arri ProRes 4444 QTs

    BobbyMurcerFan:

    What format are the original Arri files?

    What format are the transcodes?

    What OS are you using?

    And what media player are you using to view the transcodes?

     

    Arri Files are ProRes 4444 Quicktimes 3200 x1800

     

    Resolve Transcodes are 1920x1080 DNxHD 115 MXFs

    Mac OS 10.11.6

     

    I am viewing the transcodes from both systems in Avid.  The transcode made from the AMA linked file, directly in Avid is an exact match - color and gamma looks exactly the same.  The transcoded MXFs from Resolve have a different gamma - the blacks aren't as crushed.

     

     

     

     

     

     

    Avid Media Composer 8.3.1 Macbook Pro (Retina, 15-inch, Mid 2014) 2.8 GHz Intel Core i7, 16GB Ram Mac, OS 10.10.2 [view my complete system specs]
  • Thu, Jun 22 2017 3:57 AM In reply to

    Re: Difference between Avid and Resolve Transcodes of same Arri ProRes 4444 QTs

    I belive Resolve defaults to interpreting 444 codecs as being full range and not video range. I would check the Clip Attributes in Resolve and see if switching from Auto to Video helps.

    That said, Resolve may be doing things correctly, and it's MC whose levels you'll need to change.

    If you open up a parade monitor in Resolve, you should be able to tell if using Video levels clips the highlights and crushes the blacks. Granted, you'll need to look at a clip with a lot of contrast.

    Hope that helps.

    "When I spent 60k on a discreet edit digisuite system 10 years ago someone came up to me to offer fcp 2, I said it was a scam too." -Ric

  • Thu, Jun 22 2017 8:21 AM In reply to

    Re: Difference between Avid and Resolve Transcodes of same Arri ProRes 4444 QTs

    Avids Transcodes will match the AVID AMA linked clips because the Transcodes are a copy of those clips.

    As already mentioned without examining the levels (waveform monitor) of some known high contrast clips its not possible to know if Avid is correct.

    Ideally external scopes are needed to check the waveforms but if you cut some clips into a sequence and then go into color correction mode you can select one of the 3 displays to show you Y levels.

    That should help spot whats happening.

    The key is what did the camera actually record. Full range levels 0-255 (for 8 bit. 0-1024 for 10 bit) or studio/video levels 16-235 (for 8 bit 64-940 for 10 bit)

    You need to know that to be sure then enxt step is correct. Once Resolve and MC are dealing with the levels correctly you should have matching transcodes.

    ACI Moderator. I'm not employed by Avid or work for them. I just do this in my spare time. Normally using the current Media Composer version on My... [view my complete system specs]

     

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  • Thu, Jun 22 2017 9:05 AM In reply to

    Re: Difference between Avid and Resolve Transcodes of same Arri ProRes 4444 QTs

    1. Arri cameras record studio swing in all formats.

    2. Only the last versions of Resolve interpret Arri 444 footage correctly, previously they added a full swing to studio swing Lut, as did Media Composer pre 7.06.

    You should not really be baking in a 709 Lut pre grade as you are removing the whole point of having the latitude of recording the pix in LogC.

    I avoid Resolve and transcode in MC adding a non destructive Arri Log C lut in MC. You an then pass on the unadultarated media to a grade. If you import the Arri ALE you also retain all the metadata which Resolve does not.

    If you are grading in MC then you have the option of changing the LUT to suit and/or using curves in the CC.

     

    Symphony 7.06 OS 10.9.5 QT 7.6.3 Mac Pro 2x2.66 6-core 32GB Ram Aja Kona Lhi. MC 7.0.6 OS 10.9.5 Mac Pro 5.1 2x2.97 6-core 32GB ram Aja I/O express, Apple... [view my complete system specs]
  • Thu, Jun 22 2017 9:08 AM In reply to

    • S.Clements
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    Re: Difference between Avid and Resolve Transcodes of same Arri ProRes 4444 QTs

    Thanks, guys. Here are the waveforms.  Avid AMA-linked on the top and Resolve Grade on the bottom.  You can only switch between Video and Full range on export out of Resolve, as far as I can see.  Switching to video does nothing.  Switch to Full actually makes the Resolve transcode darker than the AMA-linked clip.  Based on these waveforms, it would seem as though the ama-linked footage is in the 16-235 range.  Is this what it's supposed to display at? 

     

     

     

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  • Thu, Jun 22 2017 9:18 AM In reply to

    • S.Clements
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    Re: Difference between Avid and Resolve Transcodes of same Arri ProRes 4444 QTs

    And these are the AMA Color encoding settings:

     

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  • Thu, Jun 22 2017 10:11 AM In reply to

    • S.Clements
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    Re: Difference between Avid and Resolve Transcodes of same Arri ProRes 4444 QTs

    David Yardley:

    1. Arri cameras record studio swing in all formats.

    2. Only the last versions of Resolve interpret Arri 444 footage correctly, previously they added a full swing to studio swing Lut, as did Media Composer pre 7.06.

    You should not really be baking in a 709 Lut pre grade as you are removing the whole point of having the latitude of recording the pix in LogC.

    I avoid Resolve and transcode in MC adding a non destructive Arri Log C lut in MC. You an then pass on the unadultarated media to a grade. If you import the Arri ALE you also retain all the metadata which Resolve does not.

    If you are grading in MC then you have the option of changing the LUT to suit and/or using curves in the CC.

     

    Thanks for all this, David.  Unfortunately, the workflow is not my decision.  I must go the Resolve route.

    Avid Media Composer 8.3.1 Macbook Pro (Retina, 15-inch, Mid 2014) 2.8 GHz Intel Core i7, 16GB Ram Mac, OS 10.10.2 [view my complete system specs]
  • Thu, Jun 22 2017 10:13 AM In reply to

    Re: Difference between Avid and Resolve Transcodes of same Arri ProRes 4444 QTs

    Thats interesting. The first color adapter implies studio levels are being scaled to full swing levels.

    The second color adapter then looks to bring that back from full swing to rec 709 which is studio levels.

    That implies the raw signal isn't quite 709 studio levels and both steps are needed.

    I find the scopes in Resolve a real problem (this is from a few versions back) They tend to show the levels based on the setup.

    So for studio level source identified as such (so 16-235) it will show it on the scope as 0-255 Resolve looks to scale the scopes to suit. Which isn't great.

    ACI Moderator. I'm not employed by Avid or work for them. I just do this in my spare time. Normally using the current Media Composer version on My... [view my complete system specs]

     

    Broadcast & Post Production Consultant / Trainer  VET

     

    T 07581 201248 | E pat@vet.co.uk | W www.vet.co.uk |


    Media Composer V8.2 Review Background Render

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  • Thu, Jun 22 2017 10:15 AM In reply to

    • S.Clements
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    Re: Difference between Avid and Resolve Transcodes of same Arri ProRes 4444 QTs

    Aha!  If I go to the source settings for the AMA-linked clip and remove the transformation "Levels scaling (video levels to full range)" (which is what is chosen by default) the clip looks exactly like the Resolve transcode brought into Avid.  But, is this correct?  I must admit, the default AMA settings look punchier than the resolve transcodes, but the blacks are very black.  Any guidance here?  What is correct?  The default AMA settings or the Resolve transcodes?

    Avid Media Composer 8.3.1 Macbook Pro (Retina, 15-inch, Mid 2014) 2.8 GHz Intel Core i7, 16GB Ram Mac, OS 10.10.2 [view my complete system specs]
  • Thu, Jun 22 2017 10:16 AM In reply to

    Re: Difference between Avid and Resolve Transcodes of same Arri ProRes 4444 QTs

    You should not be adding a Video to full range LUT, Arri footage is video range.

    Symphony 7.06 OS 10.9.5 QT 7.6.3 Mac Pro 2x2.66 6-core 32GB Ram Aja Kona Lhi. MC 7.0.6 OS 10.9.5 Mac Pro 5.1 2x2.97 6-core 32GB ram Aja I/O express, Apple... [view my complete system specs]
  • Thu, Jun 22 2017 10:22 AM In reply to

    Re: Difference between Avid and Resolve Transcodes of same Arri ProRes 4444 QTs

    Arri stuff is definitely Studio/video swing, (They give the reason that many softwares interpret it wrongly so they err on safety) so you just need the ArriLogC lut in MC for it to be "as intended."

    Trust Media Composer over the feebie stuff :)

     

    Symphony 7.06 OS 10.9.5 QT 7.6.3 Mac Pro 2x2.66 6-core 32GB Ram Aja Kona Lhi. MC 7.0.6 OS 10.9.5 Mac Pro 5.1 2x2.97 6-core 32GB ram Aja I/O express, Apple... [view my complete system specs]
  • Thu, Jun 22 2017 10:25 AM In reply to

    • S.Clements
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    Re: Difference between Avid and Resolve Transcodes of same Arri ProRes 4444 QTs

    David Yardley:

    You should not be adding a Video to full range LUT, Arri footage is video range.

    Thanks, David.  So what you're saying is that the default AMA settings are incorrect and therefore, if the resolve transcodes match the AMA-linked clips with the "Levels scaling (video levels to full range)" removed, the resolve transcodes are correct?

    So, I should definitely remove the first color transformation if transcoding the AMA-linked clips:

     

     

     

     

    Avid Media Composer 8.3.1 Macbook Pro (Retina, 15-inch, Mid 2014) 2.8 GHz Intel Core i7, 16GB Ram Mac, OS 10.10.2 [view my complete system specs]
  • Thu, Jun 22 2017 10:28 AM In reply to

    • S.Clements
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    Re: Difference between Avid and Resolve Transcodes of same Arri ProRes 4444 QTs

    David Yardley:

    Arri stuff is definitely Studio/video swing, (They give the reason that many softwares interpret it wrongly so they err on safety) so you just need the ArriLogC lut in MC for it to be "as intended."

    Trust Media Composer over the feebie stuff :)

     

    But, it appears that in this case, Avid has guessed wrong about how the Arri material is supposed to be treated, by forcing the uneeded color transformation.

    Avid Media Composer 8.3.1 Macbook Pro (Retina, 15-inch, Mid 2014) 2.8 GHz Intel Core i7, 16GB Ram Mac, OS 10.10.2 [view my complete system specs]
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