FORUMS: list search recent posts

Redcine to prores on pc: color shift

COW Forums : Apple Final Cut Pro X

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
Jeff Markgraf
Redcine to prores on pc: color shift
on Mar 29, 2015 at 10:22:31 pm

Hello bovines

This is indirectly an X question, since the footage will be edited in x.

A friend is converting red 5k footage to pro res via redcine x. Not his first time. He's trying out the process on his pc (built for working in Maya) because it has a smoking new in invidia card that renders crazy fast.

It seems the rendered file has a color shift compared to the original footage. A side by side comparison of the file next to the redcine original footage window shows a slight washing out of colors in the prores. Apparently this doesn't happen when doing the rendering on a Mac.

Is anyone aware of an issue rendering to prores on a pc? Thoughts?


Return to posts index

Noah Kadner
Re: Redcine to prores on pc: color shift
on Mar 29, 2015 at 10:30:21 pm

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
Call Box Training


Return to posts index

Jeff Markgraf
Re: dcine to prores on pc: color shift
on Mar 29, 2015 at 11:11:19 pm

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?


Return to posts index


John Rofrano
Re: dcine to prores on pc: color shift
on Apr 1, 2015 at 11:01:57 am

[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



Return to posts index

Jeff Markgraf
Re: dcine to prores on pc: color shift
on Apr 1, 2015 at 11:11:07 pm

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.


Return to posts index

John Rofrano
Re: dcine to prores on pc: color shift
on Apr 2, 2015 at 1:27:09 pm

I'm not sure about using a Sonnet TB to PCI box but it would need to have it's own power supply with two cables to supply the auxiliary power that all high-end GPU cards need today in addition to the power they get from the PCIe bus. Sorry I can't help you there.

~jr

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



Return to posts index


Jeremy Garchow
Re: Redcine to prores on pc: color shift
on Mar 29, 2015 at 10:42:04 pm

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.


Return to posts index

Jeff Markgraf
Re: dcine to prores on pc: color shift
on Mar 29, 2015 at 11:08:03 pm

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.


Return to posts index

Jeremy Garchow
Re: dcine to prores on pc: color shift
on Mar 30, 2015 at 12:58:01 am

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.


Return to posts index


Lance Bachelder
Re: dcine to prores on pc: color shift
on Mar 30, 2015 at 4:25:27 am

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
http://www.imdb.com/name/nm1680680/?ref_=fn_al_nm_1


Return to posts index

Jeff Markgraf
Re: dcine to prores on pc: color shift
on Mar 30, 2015 at 5:48:55 am

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.


Return to posts index

Jeff Markgraf
Re: dcine to prores on pc: color shift
on Mar 30, 2015 at 5:46:04 am

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.


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]