FS7: Gamma Shift when Transcoding XAVC

S

sk85

Member
I transcoded a few clips of XAVC-I 23.978 4K to Quicktime DNxHR. The FS7 was shooting slog3.cine. I noticed the gamma shifted when transcoding via Adobe Media Enocer. When I used 444 the shift was so small I only noticed it on a waveform. When I used HQ the shift was fairly noticeable. Oddly transcoding to DNxHR HQ made the image lest contrasty, it shifted the highlights down and the shadows up. It doesn't matter if I use 709 or 444. I have attached screenshots of each at the botom. Does anyone know why this happens or how to avoid it?. I don't consider it a huge problem I am just curious.

Also if this is in the wrong forum I apologize.

Thanks
Original.jpgHQ 709.jpgHQ RGB.jpg444 709.jpg444 RGB.jpg
 
Check how Media Encoder is setup to handle 0-255 to 16-235 conversions, I'm pretty sure it's just the full range level to video level conversion shenanigans.
 
antcaladine said:
Not sure if it's to do with your choice of codec, because of 8 bit/10bit. Dnxhrhq is only 8 bit. You need to choose ones ending with an x next to it, which means 10bit, which in this case is actually 12 bit. Same for 444.
see here http://avid.force.com/pkb/articles/en_US/White_Paper/DNxHR-Codec-Bandwidth-Specifications
why are you transcoding to dnx? Avid and premiere both happily edit xavc-i
Click to expand...
While PP can edit XAVC is it able to spit out an accurate FCP7 XML file? PPCS6 was not in my experience, which made it useless in use with Resolve.
 
Thanks for the responses. I only transcoded a few clips from Premiere because they had the warp stabilizer effect applied. Nirv, you are probably right about video level issues.
 
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