Tuesday, November 10, 2015

Re: [Avid-L2] Adobe Media Encoder is misreading video levels?

 

I did some tests as you suggested and exported bars at 601/709 same as source and QT reference and the same for RGB.  Ran the QT references through QT Pro to Save as self contained .  When I used AME to convert to XDCAM 50 both the RGB level files worked correctly and the 601/709 files came back washed out.  I did the same with just the QT reference files in AME and they exhibited the same behavior. 

So now I know if destined to go to AME for XDCAM 50 conversion an RGB level export is in order.  Odd that going .mov to .mov when I was adding pulldown the levels are correct in the resulting files.  I believe the term Adobe uses is Profiles and it applies Profiles to match what it thinks the hardware and or software target destination will need to play a file properly.  



---In avid-l2@yahoogroups.com, <pale.edit@...> wrote :

For what it's worth, I think both Adobe Media Encoder and Apple Compressor ignore the 601-709/RGB flag used by the Avid Codec.  They just assume RGB.  You may want to run a test to confirm that, but it's been my experience that it's true.  Coming from an Avid centric world, it's pretty frustrating, but no other widely codec has a setting like that...so I guess it's not surprising.



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On Mon, Nov 9, 2015 at 8:16 PM -0800, "John Moore bigfish@... [Avid-L2]" <Avid-L2@yahoogroups.com> wrote:

 

I've exported from Avid a QT ref of a 23.976 sequence and then did a save as.  All that worked perfectly.  I can ama back to the file and levels are perfect.  I then used Adobe Media Encoder to add pulldown using the .mov I made from the above process.  Again when I ama back the levels are perfect and it's 59.94i with 3:2 pulldown added.  Yes backwards cadence but will work for our purposes.

Now I've been asked to generate and XDCAM 50 422 file.  I took the original 23.976 .mov I originally made and set Adobe Media Encoder the the XDCAM 50 NTSC 60i preset and modify it to handle 10 audio tracks.  The resulting file when ama'd back into Avid is washed out and low in peak video level.  It's like it wanted RGB but was given 601/709 levels to do the encoding.  I'm assuming this means that Adobe Media Encoder changes it's gain structure depending on the target codec.  I've googled and checked some forums but can't seem to find anything that directly mentions a setting to tell Adobe Media Encoder the source is 601/709 so map it accordingly to the resulting XDCAM 50 mxf file.

I have always ama linked back to XDCAM 50 files I've exported from Avid and the levels have been fine.  If I didn't have to do the frame rate conversion I would export direct from Avid but then I can only have 8 tracks of audio.  At least that's what it has always done for me in the past.  I end up with an XDCam file with 8 tracks even if there were only 6 in the timeline.  I suppose I could try exporting XDCAM 50 out of Avid and then use AME to do the frame rate conversion but that still leaves me 2 audio tracks shy of what I need.

Does AME have any provision to correct the level shift I'm seeing?  Also is ama linking back to the resulting files a valid way to check for proper video essence in the file.  When I'm ama'd to the AME files there are no source setting allowed so I it's WYSIWYG.  Any suggestions appreciated.
 
John Moore Barking Trout Productions Studio City, CA bigfish@...

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