Question about Rendering Degradation in Grading/Onlining Apple ProRes 422 Files

[Jef Huey]

Hi Joe,

I understand the issues of compressed codecs. My comments have been about the use of an uncompressed codec. Sorry if I was not clear enough about that.

Cheers

Jef

[Jef Huey]

Hi Juan,

I want to be sure we are discussing the same thing here as I feel we may be missing some things.

I am talking about working inside an NLE with a source file of uncompressed YUV material where any rendering will be YUV based. FCP seems to fall into that category assuming projects setting are set so.

Also, one note from Marco’s codec test. “Please also note that these are RGB to YUV render tests and NOT a native YUV render test.” So any comments he makes are not pertinent to this discussion.

Ok, all that said, in the case where a YUV file is brought into FCP and a black mask is added and NO image interpolation is performed, you say that the entire frame must go through processing path. No argument from me. Where I do not understand you is that it seems as if you are saying that pixels in the middle of the frame – far away from the mask area – have been changed merely by the processing path. Is that correct? If so, then either FCP is doing something that most other NLEs do NOT do or I disagree with you.

I have talked with developers of several NLEs (though not FCP) about this issue in the past. They assured me that in an uncompressed environment only the pixels that needed to be changed by a process WERE changed. All others were left unaffected. If you have documentation to prove otherwise I would love to read it.

Thanks,
Jef

[Michaelmaier]

[Pepijn Klijs] “However, one tip to the original poster: if you are concerned about making generations, try to finish in Resolve. You can do the blanking, scaling and add your final audio track. You can also render out titles with sn alpha channel from something like after effects or motion and add them to your resolve timeline.”

Yes. I 100% agree with this. I think it would be the best option. Definitely better than going back to FCP.

[Michaelmaier]

[Juan Salvo] “Resolve can easily add blanking to any desired aspect ratio, and also do repositions as needed. I’d recommend doing this in the color session, as Resolves scaling is far superior to that of FCP, plus you’d do your scaling, cropping and color in one codec cycle.”

Sure. But if he would still need to go back to FCP to master it he would still be recompressing to the final output.

I think a better suggestion would be to master and finish it from Resolve, like Pepijn Klijs said.

[Michaelmaier]

In my opinion you should always avoid any recompression like the plague. The less the better. So I would try to master and finish it in Resolve, like Pepijn Klijs said. That way you would only have one recompression. To the final delivery format. That is if you would be working with the original files in Resolve through an EDL/AAF/XML import.