Today I experimented more and found if I start with the default source setting for my DPX 10 Rec 709 image sequence exported from Avid as legal level which AME sets to Full Range in the Source Setting/Cineon Setting which doesn't have log checked and the gamma is 1 I can make things work. Default Full Range sets Input White and Black points for 10 bit 1023, 0. Converted White and black point is default 255, 0
I found if I set the input White and Black to 940, 64 given my DPX is 10 bit and then keep the Converted White and Black Point set to 255, 0 then the resulting ProResHQ 2K file ama links into Avid at correct legal levels with no need to set source settings in Avid to scale the file.
It seems like I'm cheating the system in that the DPX was made set to export legal level but the AME Cineon Source Setting is in essence doing a scale from legal to full range. It seem that then AME takes that full range and scales it back down to legal when creating the ProResHQ file.
I've been told for a very long time that ama linking in Avid with no scalers on the source settings is a clear indication of the actual video essence level of the file. So scaling it up before AME scales it down seems to work. Given all this is inside AME does this mean that AME always wants to create ProResHQ at legal video levels? I've heard over the years that the standard assumption of video level for ProRes is Legal level but things always seem to get out of whack along the production/post production food chain.
Would I be correct in assuming AME 2015 is assuming that my DPX file is Full Range and thus scaling the video essence Full to Legal without realizing the DPX essence is in fact legal level to begin with? I've been delivering my DPX's as legal level as per delivery specs and they have worked correctly for IMF creation out of house so clearly a legal level DPX is not Taboo. I've also had on a few occasions people using clipster tell me my ProRes levels are Full Range when I know they are in fact legal. When this has happened I've told the operators and they have found that their clipster had misinterpreted my file but I never have found out if that was because my file had an incorrect metadata flag, if one exists for video level, or if it was an operator error or assumption.
I have found in the past when I exported QT Ref to AME to make XDCam master files I had to tell Avid to export QT Ref as Full Range then the resulting XDCam files would link back into Avid at correct legal level. I think in those cases it's more to do with DNX media's odd way of flagging legal vs full range that other codecs don't use. But this is just an assumption on my part. The whole level dance combined with the wonderful world of production LUTs make s a career in Herding Cats a possible next step for me. ;-)
---In Avid-L2@yahoogroups.com, <bigfish@...> wrote :
I have been successfully exporting 10bit DPX legal level out of Avid for IMF creation. I find if I take the DPX file into Adobe Media Encoder and encode to a ProResHQ 2K from 4096x-2160 DPX the results are scaled Full Range to Legal resulting in an incorrect level in the ProResHQ file. If I ama link into avid and add a legal to Full Range source setting scaler it looks fine.
In investigating I found I can right click on the file and there is a source setting which lists Full Range, Video and a few others. I thought I had struck gold and finally found the answer to my various scaling issues in AME but when I clicked video and it displayed converted white point and black point at 235 and 16 it seems like what I wanted but the results are all whacked choosing anything other than full range. It appears the source setting is for Cineon files. I'm just starting to google but can anyone shed light on what the spirit of the source settings choices are? the is AME 2015.
John Moore Barking Trout Productions Studio City, CA bigfish@...
