Latest post Thu, Mar 23 2017 2:52 PM by Kevin Klimek. 16 replies.
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  • Tue, Mar 21 2017 11:23 PM

    • Jason NLC
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    Brightness Shifts Same as Source

    I just installed the latest version of avid.  I also reset all of my system preferences (erasing the old ones).  When I export SAME AS SOURCE as my sequence (Avid DNXHD 145 Quicktime MOV), the file has shots that have quick shifts in brightness.  Is there a setting I need to change to prevent that?

    Thanks!

  • Wed, Mar 22 2017 12:08 AM In reply to

    • gumbaedit
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    Re: Brightness Shifts Same as Source

    Where are you seeing these brightness shifts?  Is it while playing in the quicktime application?  Playing out over hdmi to a consumer lcd tv?  Out of an I/o card to a broadcast spec monitor?  I'm assuming you mean in quictime player, but want to be certain.

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  • Wed, Mar 22 2017 12:12 AM In reply to

    Re: Brightness Shifts Same as Source

    Which do you have checked in the export options. Keep as Legal? or Scale from Legal to full Range?

    FWIW I have always been a huge fan of making a video mixdown before exporting to avoid strange occurences in the export process.

  • Wed, Mar 22 2017 4:25 AM In reply to

    • mjolnarn
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    Re: Brightness Shifts Same as Source

    It´s a bug since 8.70 and FFW .

    Switch off GPU render and rerender.

    Although this is the Mac side of the house I suppose you are on PC as this is PC only

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    Tomas 

     

  • Wed, Mar 22 2017 10:12 AM In reply to

    Re: Brightness Shifts Same as Source

    I've noticed this for years, many versions - when viewing using QuickTime, on systems that have FCP suite products installed, where DNx media is layered over/under codecs that Apple supplies QuickTime components for, especially ProRes, XDCam, and a few others.

    In other words, if I have DNxHD video, then key a ProRes graphic over it, the result will look fine in the timeline, but then on export, QuickTime will display that section with a brightness shift when it hits the ProRes graphic.  Same goes for DNxHD graphics keyed over ProRes media.

    Workaround is to not mix codecs, like working entirely (media and renders) in ProRes, or DNxHD/DNxHR.  OR, do a mixdown then export.

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  • Wed, Mar 22 2017 7:26 PM In reply to

    • Jason NLC
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    Re: Brightness Shifts Same as Source

    I SEE IT PLAYING BACK ON MY COMPUTER IN THE QUICKTIME PLAYER.

  • Wed, Mar 22 2017 7:26 PM In reply to

    • Jason NLC
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    Re: Brightness Shifts Same as Source

    I AM ON A MAC.  NOT PC.

  • Wed, Mar 22 2017 7:31 PM In reply to

    Re: Brightness Shifts Same as Source

    Is there a mix of media in your sequence? QuickTime is known to adjust levels on the fly depending on whether the material is 709 or RGB.

    I would check to see if the areas you see changes are different than other areas. The safest method, as mentioned, is to perfoem a video mixdown first.

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  • Wed, Mar 22 2017 7:32 PM In reply to

    • Jason NLC
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    Re: Brightness Shifts Same as Source

    WHICH ONE SHOULD IT BE ON:

     

    Keep as Legal or Scale from Legal to full Range

     

    These files are for air on tv, so I was thinking Keep as Legal?

  • Wed, Mar 22 2017 7:43 PM In reply to

    Re: Brightness Shifts Same as Source

    Yes, keep as legal. But if your material was imported incorrectly, your levels could be incorrect as well.

    "Keep legal" just basically exports your sequence as-is. Black levels at 16 remain at 16 and white levels at 235 remain at 235. Going to "Full Range" would remap your values for black from 16 to 0 and for white from 235 to 255, with adjustments in between.

    But if you "keep legal" and your blacks are 0 and whites are 0 they will pass through and stay that way (and therefore, not be legal.)

    And please don't use caps lock...it's akin to shouting.

    Symphony v2019 | OS 10.13.6 • Nitris DX • 12-core MacPro (Mid 2012) • 36 GB RAM • Facilis Terrablock 24EX [view my complete system specs]

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  • Wed, Mar 22 2017 7:48 PM In reply to

    • Jason NLC
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    Re: Brightness Shifts Same as Source

    I do have a lot of mixed media, but I always do.  Before I last updated avid, I was able to do export same as source files without any brightness shifts.  That makes me think it's a setting I am missing somewhere.

  • Wed, Mar 22 2017 8:30 PM In reply to

    • Jason NLC
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    Re: Brightness Shifts Same as Source

    SOORY, I mean:  sorry

    :-)

  • Wed, Mar 22 2017 10:44 PM In reply to

    • Jason NLC
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    Re: Brightness Shifts Same as Source

    I am using a MAC.  I went to RENDER SETTINGS and disable GPU effects.  I hope this helps.  I can do a video mixdown, but I am hoping to avoid it.  Seems like an extra step.

     

    Some of my source materail is pro res.  Some of it has been transcoded to DNXHD.  It's a mix.

     

     

  • Wed, Mar 22 2017 11:56 PM In reply to

    • tpowell
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    Re: Brightness Shifts Same as Source

    Hi Jason. The video mixdown is an extra step, but I think it is worth it. For some reason, it even seems faster. I do 9 camera multicam editing, so I transcode to DNX (from XDCam) so that everything runs smoothly. ProRes doesn't seem to work as well on multicam. Since I must deliver in ProRes, I do a video mixdown to ProRes, then export SAS. I haven't tested it, but it seems like doing the video mixdown and the export is much faster than just a straight export to ProRes. I did two seasons of this show without the mixdown and had problems. Using video mixdown and SAS export for the last two seasons, I have had no problems. The broadcaster and web people are much happier!

  • Thu, Mar 23 2017 12:13 AM In reply to

    • jef
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    Re: Brightness Shifts Same as Source

    I heartily agree with tpowell.

    There is another less known reason for doing the mixdown: To ensure that the final file has only 1 media type inside.

    What, you ask?

    Same as source means what it says. Let's say you have a simple sequence, first clip is DNx 115, second clip is XDCam50.  You now do a SAS export.

    The ciip you produce will actually have 2 media types buried inside.  The clip will SAY DNx 115 as that is the first codec in the new clip.  We have seen this happen mulitple times with clips sent to us.  And some tools will show Media Unavailable when the underlying codec is something it can not understand.  So doing a Mixdown basically guatantees that you have only one codec type.

    Jef

    Avid DS 11.0.2 R.I.P | MC "Well, it depends ..." 2021 iMac w Big Sur [view my complete system specs]

    _____________________________________________

    Jef Huey

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