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CREATING PROXIES USING RESOLVE

PostPosted: Wed Aug 22, 2012 10:23 am
by laureall
I'm presently working on a project shot with Alexa Camera. The format recording is ProRes 4444. I'm using Da Vinci Resolve (Lite version) to apply a 3D Lut and export MXF proxies for Media Composer (DNxHD 36).

It is the first time I'm doing this so I'm totally novice...
I found - for those who are interested - an Arri Guide which is much detailled and very helpfull for me :
www.arri.de/?eID=registration&file_uid=7771

But I have a problem with some shots when viewing MXF on AVid : it concerns usually quick movements especially when it is very bright (almost overexposure).
The laboratory confirms that nothing is wrong on rushes ProRes but I see jerk on this movement - a kind of flicking.

Does someone have any idea of what it is ? Wrong settings ? Rendering not efficiant ? Or the only reason that they are proxies and can't be as good as HD dailies ?

Thank you for helping

Re: CREATING PROXIES USING RESOLVE

PostPosted: Wed Aug 22, 2012 6:37 pm
by Tashi Trieu
What are the specs of the system you are running Resolve on?

I've had issues in the past with flickering in the highlights when applying a LUT on systems using ATI graphics. That was back in version 8. Haven't tried it in 9.

Re: CREATING PROXIES USING RESOLVE

PostPosted: Thu Aug 23, 2012 10:32 am
by laureall
I'm using
- a MacPro 2.8GHz Quad Core / 8 Go RAM
- Os X version 10.6.8
- Resolve 8.2
- ATI Radeon HD 5770 (I only have one : would it be the reason ???)

The LUT was generated by the laboratory (.cube), I added it on library.

I am aware this is not a certified configuration, but I am just using Resolve to create Proxies...

Re: CREATING PROXIES USING RESOLVE

PostPosted: Thu Aug 23, 2012 11:43 am
by Pat Inhofer
A normal trouble-shooting step I'd use:

Re-render the Proxies without the LUT.

If the problem still exists, it's not the LUT.

If the problem goes away, render the Proxies using a different LUT - preferably one of the ones that ship with Resolve. Depending on the results it'll help you isolate if its a problem with the LUT that was delivered to you.

Re: CREATING PROXIES USING RESOLVE

PostPosted: Thu Aug 23, 2012 6:07 pm
by dariobigi
I'm seeing something similar with RED footage to Avid DNxHD 36. It might just be a limitation of the Avid codec. It is for "offline" editing. We were going to test one or two shots (uprez/ingest) at DNxHD 175x (24p) and see if it's still happening but we haven't had a chance yet. I would recommend you try that.

Re: CREATING PROXIES USING RESOLVE

PostPosted: Thu Aug 23, 2012 7:30 pm
by Tashi Trieu
I've noticed that problem when using several LUTs that are totally fine and work on the same footage in other conditions. Source footage is Alexa ProRes 4444 Log C. The highlights appear to flicker and banding is usually visible. This would happen during playback in Resolve and during export to ProRes or MXF, but not in the exact same ways each time. Playing it back a second or third time would show artifacts on different frames that before.

Wish I still had a screen shot to compare and see if this is a same issue you're having. Can you post one?

Seen the problem on a MacBook Pro (17-inch, Early 2011, AMD Radeon HD 6750M 1024MB) and on a 2011 iMac, both running 8.2 and earlier. Using that exact same LUT and footage on system with a GTX570, no glitches and artifacts whatsoever.

I've loaded the 9.0b3 on the MacBook Pro and using the same footage, same LUT's, I'm not seeing a problem.

Re: CREATING PROXIES USING RESOLVE

PostPosted: Sat Sep 08, 2012 5:36 pm
by Tashi Trieu
See Peter's response to this post:
viewtopic.php?f=3&t=772

Re: CREATING PROXIES USING RESOLVE

PostPosted: Mon Sep 10, 2012 2:27 pm
by Gerhard Riesenhuber
Hi all,

I haven't read everything, but I think you're talking about a problem I also had.
I used the Input LUT selection to put the ARRI conversion LUT onto Alexa Prores footage
and it showed crazy artefacts on different frames. I changed to put the LUT in
a node in the track-section of the color tab and everything worked fine on playback
and rendering. This was Resolve Lite vers. 8 with only one ATI Radeon 5770.
Maybe this problem is still relevant.

Best regards,
Gerhard

Re: CREATING PROXIES USING RESOLVE

PostPosted: Mon Sep 10, 2012 4:55 pm
by Peter McAuley
I've seen similar banding or flashing with luts applied. Often it can be the GPU not rendering fast enough and choking. Don't use maximum setting for the render speed, try 50 or 25% or less. It will likely remove the artifact but of course it will take longer to render out.

Re: CREATING PROXIES USING RESOLVE

PostPosted: Mon Sep 10, 2012 5:41 pm
by Gerhard Riesenhuber
In my case reducing the renderspeed didn't solve the problem.