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Tuesday, July 30, 2013

Choosing the right workflow for the Blackmagic Cinema Camera (2/3)

Choosing the right software path to process the Blackmagic Cinema Camera

  • Creating Dailies/Proxies


Even compressed, the blackmagic cinema camera files are actually quite heavy. We therefore decided to use proxies for editing, which will be created on set, after each day; Indeed, the proxies that will be used for editing will be the color-graded dailies I will give to our director after each day. 

The software used to create proxy is the one that Blackmagic gives with the Blackmagic Cinema Camera: DaVinci Resolve

Near the set, where the team will sleep, will be a computer, with DaVinci Resolve installed. After each day of shooting, all the files will be transferred in external hard drives connected to that computer. Once transferred, all these files will then be imported into DaVinci Resolve, where I will apply a LUT (more on that later) and then export the files, individually, as proxies. (See a future blog post to see how to properly export proxies in DaVinci Resolve)

It is very important to choose the right file format for your proxies. I did some tests, to see which format would give me a decent picture quality for the minimum file size, with a short render time. 

I excluded the H.264 codec: since the proxies will be used for editing, I wanted to use a format that uses «complete» frames. H.264 is a broadcasting codec, but is not fit for proper editing: indeed, the frames are not rendered individually, but in comparisons to the ones adjacent to them. While Adobe Premiere handles H.264 files marvelously, I decided it was time to edit with a proper codec for once. 

The choice was made, therefore, to export the dailies as DNxHD 36 8 bit files. DNxHD, created by Avid, is an editing codec, in that each frame exist separately in the file, so that when you cut your video, you cut at that precise frame (it seems obvious, and it should be. But with h.264, it is not always obvious.) The files look great with the LUT applied, the file size isn’t too big, and it will be easy to import and edit them. 

  • Editing the proxies

Now that the proxies are made, we have to choose the software that we will use for editing. 

The point of my workflow was to be fast, and as universaly compatible as possible. We will use several of our personal computers, each of which with different operating systems and configuration, so I needed a workflow that could work on any machine, and any number of machine. 

This excluded Final Cut Pro immediately, since it is not available on PC. We were left with Avid Media Composer and Adobe Premiere (No one on the team knew Vegas, therefore it was not considered as an option). 

Avid Media Composer is venerable, in that it’s been there for decades, and many movies has been edited with it. But DEAR GOD IS IT ANNOYING. Every single project we edited with Avid in the past has caused us issues. While Avid is surely very adapted to a very controlled (confined) environment, for a project that needs a lot of flexibility, Adobe Premiere was an obvious choice. It is very fast, convenient  scalable. Adobe Premiere CC even handles DNxHD files natively now (CS6 and previous versions handle DNxHD files as well, you just need to download the codec from the Avid website)

The choice was made: Adobe Premiere will be the editing software for Incompatibles.

  • The roundtrip


Working with proxies demands a very organized and segmented workflow. Once the proxies exported, they are imported into Premiere where our editors cut the film. Once the editing is final, they export an Final Cut Pro xml file (from Premiere, it’s just called a Final Cut Pro xml, even though Final Cut is never part of our workflow) of the project. 

I, the color artist, will need this xml file (it’s basically a text file, it’s tiny, therefore you can share it easily with Dropbox) and the original files (several terabytes of data. Don’t use Dropbox). All I need, is then to open the Resolve project with all my original files imported, and import the xml. The files will automatically be cut into a new timeline, where I can start my grading. Once it’s done, I can finally export the graded project, as one high quality file. This file will then be added back into Adobe Premiere, where we will add the titles, and the mixed sound. 

  • To summarize

       1. Create the proxies with DaVinci Resolve
    • DNxHD 36 8 bit, separated files
        2. Import and edit the proxies with Adobe Premiere
        3. Once the edit is final, export the timeline
    • Final Cut Pro xml (within Adobe Premiere)
        4. Import the Final Cut Pro xml file into DaVinci Resolve, and grade the film
        5. Export the film from DaVinci Resolve
    • DNxHD 186 (to be determined), in one file
        6. Import the graded file back into Premiere, add titles
        7. Export the «master» file to the format you need, depending on the diffusion, with Adobe Media Encoder

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