DaVinci Resolve Export Tutorial Available?

[pbzvariety]

Hi folks,

I'm an experienced editor, newbie colorist, and newbie DCP needer...

I've done all the research I could online, and I'd like to give DCP-o-matic a try. While I find troubleshooting aritcles and am trying to piece an understanding together, I'm wondering if anyone has a simple tutorial about how to export needed materials from DaVinci Resolve that would lead to the best possible quality of creating a DCP in DCP-o-matic... and hopefully it says how to set up DCPomatic from there, but there are other tutorials for that, I know.

btw, I shot ProRes HQ, cut on Final Cut Pro 7 in that format, exported in that format, graded in DaVinci Resolve in that format (in Rec 709 color space), and cropped it to 1920x817 (2.35:1) and am ready to go.

Thank you!

[Carsten]

I don't know any specific tutorial, there may be some reports on some blogs and such.

This forum has a few stories.
Here is a very typical example: viewtopic.php?f=2&t=829&hilit=Resolve

One major issue seems to be that many people think an export to XYZ TIFF or J2C is the only/best way to maintain quality - unfortunately, that is not necessarily the case. DPX also may be problematic, because there are different interpretations of certain parameters.

The idea to use J2C or XYZ-TIFF is based on the assumption that Resolve does a better job at color/gamma/format conversion than a 'cheap/free' tool like DCP-o-matic (now, the basic version of Resolve is free as well... )

When you import footage into DCP-o-matic with this idea in mind, you expect DCP-o-matic to bypass all image processing like color/gamma conversion, and only apply J2C compression (or even bypass J2C compression for J2C input formats). It is indeed possible to bypass color transform, gamma conversion and even J2C compression in DCP-o-matic for specific file formats - but that only works if your Resolve export files are 100% DCI conformed. People seem to think that, as XYZ or J2C is part of the DCI specs, files created by Resolve in XYZ or as J2C are DCI compliant per se, or immediately targeted at DCP creation. That is not true.

The J2C created by Resolve does not follow strict DCI compliance. The J2C from Resolve was not meant to be used directly for DCP creation. Many people miss that. I know that BMD has been working on this issue during recent years, but I don't know wether they fixed it completely in Resolve 14. Even if they made the J2C compliant with DCI code stream specs, it will still lack the proper gamma 2.6 if you don't cater for that in your pre-export workflow.

As an experienced Resolve user, I guess you know what gamma is. If you grade in rec.709, your project gamma is most probably rec.709/BT.1886/2.2/2.4.

DCI uses a 'display' gamma of 2.6. As it is, if you create J2C or XYZ-TIFFs in Resolve, the export module does NOT automatically apply an inverse 2.6 gamma to the files - the XYZ or J2C will keep the 2.2/rec.709 gamma. That is because Resolve is a pro tool. It expects the proper gamma to be created by the operator in the application, as the final step of the grade, before the export. Gamma is not metadata, but is conveyed in the image data, so you can not just output a rec.709 project and add some 'gamma 2.6 metadata'. If you export a rec.709 project to a common rec.709 format, like ProRes or DNxHD, everything is fine - DCP-o-matic rightfully expects the file to be rec.709 and will apply the proper color and gamma transform to create DCI compliant gamma 2.6 XYZ J2C files.

So, to create a proper J2C or XYZ-TIFF in Resolve, you need to convert your project/grading gamma from rec.709 to 2.6/DCI before you export. Of course you can continue to grade in rec.709, but the final step before you export a master targeted at DCP-o-matic in J2C or XYZ-TIFF must be a gamma conversion towards 2.6.

As most people use a rec.709 grading and display color space, and will most likely also need a rec.709 master file for other uses, I usually recommend to NOT go the J2C/XYZ image sequence way, but create a high bitrate rec.709 Prores or DNxHD file, also with embedded audio. At least for a beginner in DCP mastering, this is the safest way to get going. Both Prores and J2C are excellent compressors and have loads of headroom if you use sufficient high bitrates. You will not notice any of the compression artifacts that are commonly seen with MJPEG/MPEG or h.264, etc.

Note also that there is an easyDCP creator backend for Resolve. This backend WILL apply proper gamma and XYZ conversion automatically. So, XYZ/J2C created with Resolve's normal export modules are not automatically DCI compliant, but using the easyDCP module will create fully compliant DCPs. The free easyDCP export module, of course is limited by forced watermarking.

Notice that 2.35:1 is a 'classic' film based scope aspect ratio. DCI uses 2.39:1 (2048*858). If you start with HD, that computes to 1920*804. If you want to create a 'proper' DCI scope, you need to crop a few more pixels (6 from both top and bottom) off your 1920*817 project. That can be done in DCP-o-matic, while at the same time upscaling the 1920*804 frames to 2048*858.


- Carsten

[tba]

I have created a DCP tutorial for newbies but your forum won't allow adding of PDF files...?

[carl]

PDF files should be allowed now.

[tba]

'File too large ' - error!

The file is only 487kb

[tba]

Still can't upload a pdf to this forum. Can I mail it to you and let you post it on the forum?

[carl]

I've upped the file size limit to 8Mb so it should work now. If not, feel free to send it to me carl@dcpomatic.com

[tba]

sent via email

[antonarap]

Hello. What happened with the tutorial after all?