Redcine to prores on pc: color shift

[Noah Kadner]

Doesn’t surprise me- Prores on a PC is always a bit dicey as a prospect. Is the shift impossible to live with or can you simply correct it back out when you’re done. Also a note to RED inquiring about ways to avoid this would be wise.

Noah

FCPWORKS – FCPX Workflow
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[Jeremy Garchow]

You can always hook back to the Raw for a final render pass in X if needed, as long as the color metadata is saved.

Also, check your settings in FCPX. There are controls to adjust color space. Perhaps x is misinterpreting due to the nature of the files.

[Jeff Markgraf]

Jeremy
He hasn’t brought it back into x yet. I think the immediate goal is to hand off lighter files than the original 5k footage. I would just import it into X and make proxies and copy the proxies to give to the client. The hope was to use the significantly faster rendering of the pc to save time.

[Jeff Markgraf]

Noah

Haven’t seen the shift. Not sure how severe it is. I presume this is some variation on the famous QuickTime gamma shift. Does the pc prores encoder use a different process or different math from the apple encoder?

[Jeremy Garchow]

I hear you, but what I’m saying is to use those files as a proxy of sorts, and then use the raw for output.

Make sense?

This way the gamma shift or whatever is happening won’t matter. You should also check the output in X on a monitor through hardware.

[Lance Bachelder]

Have you looked at the files on a Mac yet? I’ve had renders look a little washed out in QT on PC but look fine once they were in FCPX…

It was at a Vegas premiere that I resolved to become an avid FCPX user.

Lance Bachelder
Writer, Editor, Director
Downtown Long Beach, California
https://www.imdb.com/name/nm1680680/?ref_=fn_al_nm_1

[Jeff Markgraf]

I understand. I don’t have all the details yet. He may be just handing off the rendered files and having nothing else to do with it. I’m sure the people he’s sending them to can tweak the color. I’m more interested in why it’s happening. Especially since it only seems to be on the PC side.

[Jeff Markgraf]

Hi Lance.

I haven’t seen any of it. I’m only involved to help him troubleshoot the issue. I suspect all will be fine in X. As I said, he only wants to use the PC to get access to the Invidia card’s fast rendering.

[John Rofrano]

[Jeff Markgraf] “I presume this is some variation on the famous QuickTime gamma shift.”

Have him try sending you Avid DNxHD files instead. It’s my understanding that Avid DNxHD does not suffer from this PC gamma shift problem.

[Jeff Markgraf] “Does the pc prores encoder use a different process or different math from the apple encoder?”

What is he using to create ProRes files on Windows? To my knowledge there is no Apple sanctioned ProRes encoder for the PC. Did RED license ProRes from Apple? If he’s using Redcine-X with the FFMPEG “hacked” ProRes encoder those are not “real” ProRes files and my understanding is that they will perform poorly in FCP X and require re-encoding on your Mac so what have you really gained if you were trying to off-load the encoding to his PC?

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Jeff Markgraf]

Hi John

I already suggested to him that he try DNxHD or whatever the fancy new DNx flavor is that handles big frame sizes (source is 5k RED).

He’s rendering the files through RedCine. Yes, I questioned the ProRes conversion on PC, because I didn’t think there was a sanctioned ProRes encoder for PC. He doesn’t have any more info, as he’s somewhat technical, but not full-on geek.

The next question is whether he can get Mac drivers for his fancy Invidia graphics card. If so, can he just put it in a Sonnet TB to PCI box? Last I heard, no one was sure whether you could tell the Mac to use the new graphics card. Which seems odd, since it’s just another PCI card. But maybe there’s an unresolvable conflict with 2 gfx cards connected at the same time? He loves this card, because it renders almost as fast as a Red Rocket, at least on the PC.

I’m awaiting a DNxHD test from him.