Creating DPX for DaVinci 2K color correction - revisited!

[Neil Evans]

Hey all,
Well I've been searching and despite several threads on this very topic, and a lot of discussion of the merits of DPX files and the post houses that use them, I seem to have missed the answer - and it doesn't help that you can't search for "DPX" because it's too short! So I beg everyone's indulgence.

I need to prep a 13 minute Red short for color correction on a DaVinci 2K and the post house is asking for HD-sized 10 bit log DPX files. I edited in FCP 7 with transcoded ProRes and have since linked everything in FCP back to the Red H proxies using Clipfinder.

It seems I have two basic workflow questions. First, what program should I use to create the DPX files? I know Color can create DPX files (thanks to Michael Cheung's posts & blog), but I'm not certain if that's the best option. I believe that ClipFinder could be used, I'm not sure about RCX. We don't really have the budget for Glue Tools or Monkey Extract if they're avoidable. We obviously want to be extremely cautious here and are trying to best preserve our color data, so any guidance would be greatly appreciated.

The second question is about creating the DPX files for "FX" shots. We have about 4 shots that have simple speed effects on them in FCP and about 12 shots that have some subtle keyframed scale changes to create virtual push ins. (Oh, the benefits of shooting at 4K for delivery in HD - lots of resolution to play with!) When i was exploring creating the DPX files in Color, I realized that, unsurprisingly, Color was ignoring the speed changes, and the keyframed scale changes. So what is the recommendation for getting those FX shots conformed to DPX? Should I use FCP to render new media (uncompressed or ProRes 4444) for those FX before creating the DPX files?


Thanks guys - I really appreciate this great resource!
-Neil

 

[Aaron Newsome]

Please check the Color manual and be aware of what attributes carry over and which are ignored. You might be better off doing your virtual push in from within Color itself. I believe you do this in the geometry room.

 

[Neil Evans]

That's a great suggestion Aaron! I'm totally new to Color and didn't realize that geometry was keyframeable. So do you recommend using Color to create the DPXes? The post house doesn't recommend it, but I think that's primarily because they don't use it.

 

[Neil Evans]

Unfortunately, it appears that we may not be able use Color as our coloring house can't read Color's DPX files due to the Little Endian/Big Endian issue. We may be able to use Cineon from Color for an additional fee (I'm waiting to hear), but I'd love to know if there are other options besides Color to create the DPX...

 

[Mathieu Ghekiere]

Can't you make them in Compressor 3.5.? I thought I read something like that in the manual, but I'm not sure.

 

[Neil Evans]

Another very interesting thought - it does look like Compressor can do DPX. However, wouldn't there be a quality loss because Compressor would just be using the data from the Quicktime proxies, and not from the original r3d files? I thought that was Color's big advantage - that it would refer back to the original files.

 

[Lucas Wilson]

Another very interesting thought - it does look like Compressor can do DPX. However, wouldn't there be a quality loss because Compressor would just be using the data from the Quicktime proxies, and not from the original r3d files? I thought that was Color's big advantage - that it would refer back to the original files.

Neil,

I assume you're trying to do this without spending significant extra dollars?

There are lots of ways to do what you suggest with other systems.

Best,

Lucas


Lucas Wilson
------------
Director, Business Development
ASSIMILATE, inc.
LA, CA, USA

 

[Neil Evans]

Lucas,
You assume correctly If we have no choice, of course we'll spend the money but we're laying down a good portion of our post budget for the colorist and would rather not drop any more than we have to.

I'm curious though, what are the options with other systems?

-Neil

 

[JoshBertrand]

Do you have After Effects? That would be the route I would go. Export XML from FCP, relink to R3D's in Clipfinder. Import into AE using an AE script and then render to DPX. You could also try the paid version of Clipfinder and send your FCP sequence to a Redcine-X timeline for rendering to DPX.

 

[Lucas Wilson]

Lucas,
You assume correctly If we have no choice, of course we'll spend the money but we're laying down a good portion of our post budget for the colorist and would rather not drop any more than we have to.

I'm curious though, what are the options with other systems?

-Neil

Neil,

Since I work for ASSIMILATE, of course I will promote our solution - SCRATCH. : )

But in SCRATCH, this is easy...

1) Export EDL out of FCP
2) Conform EDL to original R3D files in SCRATCH
3) Add handles as appropriate for whatever the DI house dictates
4) Render to DPX, and output final list for DI facility.

We have hundreds of customers worldwide who do this on a pretty regular basis.

Best,

Lucas


Lucas Wilson
--------------
Director, Business Development
ASSIMILATE, inc.
LA, CA, USA

email: lucas (at) assimilateinc (dot) com
url: www.assimilateinc.com

 

[Tim Whitcomb]

Why not use Redcine-X aor RocketCine-X and transcode the original R3d's to 2K DPX
from a 4K FULL Debayer via Red Rocket?

We offer the service for $50 set up fee and $25/hr with Red Rocket 4K Full Debayers.
2K DPX are slightly slower than REALTIME. So you are looking at maybe $150 to $200
plus shipping and insurance of the drives.

 

[Alex Hastings]

Hey all,
Well I've been searching and despite several threads on this very topic, and a lot of discussion of the merits of DPX files and the post houses that use them, I seem to have missed the answer - and it doesn't help that you can't search for "DPX" because it's too short! So I beg everyone's indulgence.

DPX is the most verstile format for post. LINUX, MAC, PC have no problem seeing them how they should be seen. Also the benefit of images sequences versus an encapsulated quicktime with codec is miles long. When you render if you have a corrupt frame, you fix just that frame, and render that frame for a fix. With QT you gotta render the whole thing. Fixing that 1 frame went from 2 minutes to 20 minutes just because Quicktime was involved. On a feature imagine 300 shots, adding 10x the time because of QT, you are sinking fast. Also if you are on a network, do all the systems have the right codecs? Can my super fast LINUX composting station see that ProRess 444 codec? Will there be a gamma shift because this program see's it as RGB the other as YUV? miles and miles of reasons, I could keep going for a few hours. Trust the pros. DPX is best for post.

I need to prep a 13 minute Red short for color correction on a DaVinci 2K and the post house is asking for HD-sized 10 bit log DPX files. I edited in FCP 7 with transcoded ProRes and have since linked everything in FCP back to the Red H proxies using Clipfinder.

It seems I have two basic workflow questions. First, what program should I use to create the DPX files? I know Color can create DPX files (thanks to Michael Cheung's posts & blog), but I'm not certain if that's the best option. I believe that ClipFinder could be used, I'm not sure about RCX. We don't really have the budget for Glue Tools or Monkey Extract if they're avoidable. We obviously want to be extremely cautious here and are trying to best preserve our color data, so any guidance would be greatly appreciated.

Glue Tools and Monkey extract are very inexpensive for what you are trying to do. With the going rate for Davinci, one hour of Davinci will pay for Gluetools and Monkey. COLOR will see the .R3D files, that is your best option. Render out DPX from COLOR. If your Davinci guys can read your EDL, then you render with handles, you will have more control when it goes into the Davinci. Try to get some handles, an online session with no handles can be scary.

The second question is about creating the DPX files for "FX" shots. We have about 4 shots that have simple speed effects on them in FCP and about 12 shots that have some subtle keyframed scale changes to create virtual push ins. (Oh, the benefits of shooting at 4K for delivery in HD - lots of resolution to play with!) When i was exploring creating the DPX files in Color, I realized that, unsurprisingly, Color was ignoring the speed changes, and the keyframed scale changes. So what is the recommendation for getting those FX shots conformed to DPX? Should I use FCP to render new media (uncompressed or ProRes 4444) for those FX before creating the DPX files?

With XML translation Apple Color will sometimes do pushins and pan/scan. make sure you have the lastest versions of FCP/QT.

As for speed changes, COLOR has no time remapping tools. FCP kinda does, it took them from SHAKE, but FCP without Gluetools does not do DPX. For FX, pull those shots and export to COLOR separately. For retimes, you would obviously export the entire shot, then retime in another program. SHAKE, NUKE, AE etc..

 

[Neil Evans]

Lots of excellent info and ideas here - thanks a lot guys!
-N

 

[Mark Wilkinson]

For best data path, I would render 16-bit tifs out of RedCine-X, then reassemble in AE for zooms, time remapping, etc.

Then render your 10-bit log files out of AE - make sure your post house wants 1.7 gamma -- the Clipster which often feeds the DaVinci, does not - it wants gamma 1.0. Make sure you are clear on black and white levels of the DPX (0 black, white 1023 or video levels)

If you have specific questions, feel free to PM - I feed files to DaVinci often - and there are some traps to avoid.

 

[Marc Wielage]

I would add that if you're using a daVinci 2K color corrector, many image sources (like DVS Clipster) allow the colorist to reframe images on a shot-by-shot basis. In other words, you can do all the repositions in the color-correction bay.

As far as I know, slow-motion and speed ups have to be done during the conforming process.

If you're using daVinci's newer Resolve color-corrector, the image files are handled directly by the Resolve and it can still do repositions with no problem. Same with comparable systems like Pablo, Baselight, and Scratch, each with pros and cons.

 

[Peter Chamberlain]

Are you sending the images to a daVinci 2K or DaVinci Resolve?
If daVinci 2K, you will need some HD video playout device as the old 2K does not read dpx files. IF you mean DaVinci Resolve, you don't need to convert to dpx, use the native r3d....unless your post system does not have our realtime r3d decoder, then as you say, render dpx, export the EDL and Resolve will use both.
Peter