So I've spent a lot of time on this and have been unable to get definitive answers. I thought that DNxHR 444 was RGB by default, but I believe that's not the case.

So a few questions:

1. Is DNxHR 444  RGB or YUV 444?

2. There a way to specify it to be RGB or YUV 444?

3. Is some advantage of one over the other? I've read that YUV 444 is easier to compress than RGB because the luma is seperated from the R and B color channels. But I have no idea how accurate that is.

BTW, below is screen print of how ffmpeg analized a DNxHR 444 file.

Not sure, but I would guess that whether it is RGB or YUV depends whether you have your Avid project set up as RGB or YCbCr under the Color Space selection when you create the project.

Jef 

You can't compress RGB because the values of R G & B are different (to make white) hence when you select an RGB color space your resolutions are limited to uncompressed options.

YUV (or YCrCb) does allow for compression on the CbCr components more agressively than the Y.

So 444 can be RGB or YUV 422 can only be YUV

For more info come on my Advanced files and compression course :-) 

Pat Horridge:

You can't compress RGB because the values of R G & B are different (to make white) hence when you select an RGB color space your resolutions are limited to uncompressed options.

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Hi Pat,

Thanks so much for your reply. I think the RGB compression issue may be more complicated, isn't everything, lol. As FWIU Prores 4444 can be compressed RGB.

http://www.arri.com/news/news/alexa-xrxt-supports-new-prores-4444-xq/

As for taking one of your classes, I'm in Los Angeles. But if I ever make way to the UK, I'll look you up!