FORUMS: list search recent posts

Using CinemaDng files for edit

COW Forums : Blackmagic Cinema Camera

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
Jordan McGehee
Using CinemaDng files for edit
on Jun 19, 2013 at 7:35:14 pm

I have seen a lot of articles out there debating over whether to get a fast enough RAID to edit in 12-bit RAW 2.5K vs using proxies.

I think I understand how proxies work. Please correct me if I am wrong:

1. Bring RAW 12-bit footage in to Resolve, color correct or leave as is, and use the export to Final Cut Pro option (if you are using Premiere CS6 or Final Cut Pro X).

2. Open up the XML file in Premiere or Final Cut and do your edits.

3. Export "Save as Final Cut Pro XML" in Premiere or "Export XML" in Final Cut Pro

4. Open up that XML file in Resolve and color correct if need be, or just render out final media.

Is the most efficient way to use proxies? Also does buying an expensive RAID save a ton of time or is it not worth it?


Return to posts index

Matthew Sonnenfeld
Re: Using CinemaDng files for edit
on Jun 19, 2013 at 8:58:12 pm

This is really about what a "Proxy" is. Unfortunately that is not how the workflow works.

A proxy is a low resolution version of you original footage that you use to export. Basically the workflow would be the following;

1. Bring 12bit raw footage into resolve
2. Grade or leave as is but typically a first light color correct will be beneficial for editing as you have a better idea of what it will ultimately look like.
3. Generate proxy files by exporting to an editing codec such as ProRes, DNxHD, or Cineform. DO NOT RENAME YOUR FILES!
4. Do your edit using the smaller, more manageable files.
5. Export an XML or EDL of your final sequence.
6. Import XML or EDL into Resolve.
7. Relink to your original 12bit raw files.
8. Final color grade on original files
9. Export final sequence out of resolve.

Co-President at fourB Productions, Inc.
Blackmagic Cinema Camera, RED Scarlet-X, Panasonic HPX170, Canon 7D
2011 Macbook Pro 17", 2.3 Ghz Quad Core, 16GB RAM
AJA IoXT
Adobe Production Premium CS6, Avid Symphony 6, Final Cut Pro Studio 3
The College of William and Mary


Return to posts index

Jordan McGehee
Re: Using CinemaDng files for edit
on Jun 20, 2013 at 3:56:35 pm

Thank you Matthew for clearing that up! Do you think that is a preferable workflow to paying additional money for an expensive RAID in edit in real-time?


Return to posts index


Matthew Sonnenfeld
Re: Using CinemaDng files for edit
on Jun 20, 2013 at 4:24:23 pm

without a doubt, yes!

The fact is you will pay nearly $2,000 dollars for a RAID capable of hitting the speeds. And then you will fill it up very quickly. Except you probably still won't have the power that you need to actually edit it anyway because it's about more than the RAID. It's about your CPU and your GPU to do real time debayering as a raw file has not been debayered, it's about the sheer data rate of playback on all of your hardware. Remember, when editing CinemaDNG it's basically editing a straight image sequence, not video files. This takes a lot of power. Editing natively with files of that size is a lot more intensive than most give it credit for.

You will however still need a large RAID to store your masters and your transcoded media. This is a consequence of shooting in raw.

Co-President at fourB Productions, Inc.
Blackmagic Cinema Camera, RED Scarlet-X, Panasonic HPX170, Canon 7D
2011 Macbook Pro 17", 2.3 Ghz Quad Core, 16GB RAM
AJA IoXT
Adobe Production Premium CS6, Avid Symphony 6, Final Cut Pro Studio 3
The College of William and Mary


Return to posts index

Nick Timmons
Re: Using CinemaDng files for edit
on Apr 26, 2014 at 8:56:22 pm

Matthew,
I know this is an old thread, but you're flat wrong about almost everything you said. Firstly, 24fps cDNG from the Blackmagic Cinema cam is around 120 MB/s. I have single spinning hard disks that can hit that read target, but a two-drive RAID0 array would more than do the trick. How much is that, you ask? A 3TB drive can be had for around $100. You do the math.
Second, debayer is computationally expensive, but if my two-year-old midrange laptop can do it faster than realtime, I don't think it's an issue.


Return to posts index

Matthew Sonnenfeld
Re: Using CinemaDng files for edit
on Apr 26, 2014 at 10:37:31 pm

I'm curious, what is your math exactly?

You know too that 120MB/s is huge right? ProRes HQ at the same frame rate by contrast is 24.7MB/s.

What's your backup of your RAID0 array? Or when one of those two disks fails will you just apologize to your client for losing everything? Let alone that single spinning hard disk.

I would love to see a screenshot of a Blackmagic or AJA System Test of your editing system and edit drive confirming your results.

Please show me real world numbers that are consistent for the community of this forum. That's great that you can do what you can on your laptop. Hats off. Maybe you could elaborate on the specs of your laptop? Software? People might be interested to know what you are using that is proving so successful for you especially considering that this is a forum for helping people.

Co-President at fourB Productions, Inc.
Blackmagic Cinema Camera, RED Scarlet-X, Panasonic HPX170, Canon 7D
2011 Macbook Pro 17", 2.3 Ghz Quad Core, 16GB RAM
2008 Mac Pro 2.6 Ghz 8 Core, 10GB RAM
AJA IoXT, Blackmagic Intensity Pro, Blackmagic Mini Monitor
Adobe Production Premium CC, Avid Media Composer 7, Final Cut Pro Studio 3


Return to posts index

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