Are these custom exports through the QT engine? What is your source codec in the timeline.
Here's what I'm hoping, and I can't believe I have to hope this is true, I put the safe color limit effect as an upper track. My 4K 4096_2160 timeline is made up of DNxHR HQX media that was transcoded from Varicam 35 AVC-I 422 source media. My best understanding is DNxHR HQX is 12 bit. I don't know if it is 12 bit when I'm in a 709 YCbCr project as opposed to a 709 RGB project. My projects have always been 709 YCbCr as my deliverable is Rec 709 in the end. I have the render set to force the render to ProResHQ unchecking same as source. I now have Safe Color limit rendered to ProResHQ inside Avid. When I export a QT Ref at legal levels in QT Pro 7 the info says ProRes HQ. I even put submasters over filler to make sure everything is ProResHQ. I then do a save as for QC. I make all my other files in Adobe Media Encoder using the QT Ref file as a source. All this workflow avoids ever using a custom export through the QT engine out of Avid. With this I am hoping that the internal render to ProResHQ is truely 10 bit processed inside Avid so the QT Ref has to be pointing to that hopefully real 10 bit ProResHQ. I also make sure my timeline is set to 10 bit Green before rendering the ProResHQ.
If my hope above is not true then this sucks big time. I find it inconceivable that Avid is rendering to the ProResHQ codec internally and truncating to 8 bits but this whole thread is just becoming more depressing. After all the years of being told to mixdown to ProResHQ inside Avid and then export same as source I'm wondering if that will yield 8 bit or true 10 bit.
I know from past experience using a Black Magic Ultrascope's Error Logging that when I rendered to DNXHD there were no errors logged but if I did the same render to ProResHQ the scope started logging errors. I know sometimes scope alarms are over sensitive but I've grown familiar with the settings on Tek scopes and usually can trust them. The Ultrascope error log is less familiar to me but it looked to be set to EBU standards preset. Regardless of the error logs actual accuracy something in rendering to ProResHQ made the alarms go off. I have not usually equated 8 bit video with error log issues but I would think that the truncation that may be occurring if Avid us truncating the media to 8 bits might generate some specular excursions that might trigger the Ultrascope's error log. I've definitely seen this behavior error logging off tape with the HDCam and HDCam SR output enhancement circuitry generating specular errors. So I seems possible the 10 to 8 bit truncation might have a similar effect.
This whole things is making me throw up a little in my mouth.
---In Avid-L2@yahoogroups.com, <tcurren@...> wrote :
Posted by: bigfish@pacbell.net
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