Mixing Frame Rates in DaVinci Resolve – Part 5: Rendering

Mixing Frame Rates in DaVinci Resolve – Part 5: Rendering

Editor’s note: This is the final part of our series on editing with mixed frame rates in DaVinci Resolve. We already rolled out the previous parts over the last few weeks, so be sure to check out parts one, two, three, and four. But newsletter subscribers already have full access to the full 10,000+ word ultimate guide in one place. If you want that, just enter your email in the box below (if you don’t see the email box, you’re already subscribed).

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Ron Dawson
Managing Editor, Frame.io Insider

Once you’re done preparing your files, it’s time to render out your project.

In DaVinci Resolve you have two options—either you can export individual shots or the entire sequence. Resolve handles these types of rendering differently when it comes to frame rates, so let’s walk through the differences.

Individual Clip Rendering

One of the most confusing things about Resolve that is different from most other NLE’s is rendering with the Individual Clips setting. Rendering using Individual clips means that Resolve will render each individual clip in the timeline as its own file by going back to its source in the media pool and rendering just the piece of that clip that’s in the timeline.

Reasons for Individual Clip Rendering:

  1. Exporting full length proxies for editing in another application
  2. Exporting files to conform your edit in another application
  3. Exporting up-resed media to use in another application
  4. Exporting files for VFX or graphics work without any timeline effects
  5. Exporting trimmed colored files and conforming them in another application

Open up one of our camera sequences with mixed frame rates. Go to the deliver page. Change the render setting to individual clips. Make sure that the timeline is set to render the entire timeline. Pick 1920×1080 ProResLT as the video format. Change the file naming to source file and pick a location to render the files. Add the timeline to the render queue and hit render.

 

Resolve will render each clip separately at it’s own frame rate in the project. It won’t render the clips at the timeline frame rate. It will also embed the clip’s timecode as it is in the project which might or might not match the embedded source file timecode. If the frame rate was changed in clip attributes, the timecode in the newly rendered file won’t match source file timecode.

Since Resolve was originally a color grading application, this type of rendering was intended to render out colored clips with the same start and end timecode as the edit files with a few frames of handles on either side if needed. Then those colored files would be used to conform to a locked edit in a different finishing application. Timecode would match between camera original files, transcodes, editorial, color, and finishing. Resolve is used for more than color grading now, but the idea behind individual clip rendering hasn’t changed that much.

For example, if you have a complicated edit and you render with the individual clips setting, some unexpected frame rate issues effects can happen. Resolve will render the original frame rate of the file in the project with the project timecode, not how it exists in the timeline. Any speed effects or speed keyframes that were used in the timeline are bypassed. If you have keyframed power windows, time-specific effects or stabilizations, rendering out individual clips may shift things around differently than expected. Some of those effects will need to be removed before rendering or re-built in another application.

Earlier in the article, we discussed changing a clip’s frame rate in clip attributes. If we do this, Resolve will render out the new changed frame rate and timecode reflected in the project with the individual clip setting, not the frame rate or timecode embedded in the file. When deciding on changing your clip attributes, it’s important to understand this distinction. Depending on your workflow, it can be helpful to match your source file frame rates to your project frame rate by changing the clip attributes before editing. Then when it comes time to render, your files will render at their expected frame rate.

In general, using Individual clips works best when you’re only using Resolve as a color grading application, a camera file processor, or media hub. Generally, if you need to pass files to another vendor or artist. If you’re using Resolve more as an editor or finishing with Resolve, rendering individual clips can add more confusion to the process because of effects and speed changes used. Single clip will be a better option for editing or finishing work.

There is one workaround for rendering individual clips with effects and re-times applied: using compound clips.  You can make each clip with a speed change into a compound clip. Resolve creates a new clip in the media pool with timecode that matches the sequence timecode.  Then when you render your sequence with individual clips, Resolve will pull from your compound clip which will match it’s sequence settings instead of the source file.

It can become complicated to manage compound clips especially if you want to maintain source timecode, but for certain workflows it can help to have this option.  Having to add each clip with a color grade or timeline effect to a compound clip, naming the clip, organizing your renders can be more time intensive than using the other option below.

Single Clip Rendering

Most NLE’s use a render setting like single clip when exporting. The single clip setting will export your timeline as one long clip. You set the ins and outs or render out your entire sequence. Only one clip will be created.

Reasons for Single Clip Rendering:

  1. Exporting edits
  2. Exporting a conformed edit timeline
  3. Exporting a colored timeline with baked in effects from editorial
  4. Exporting a finished a film or commercial

With single clip, Resolve will use the timeline frame rate to render. By default, the frame rate of new sequences will match the project settings. However, with Resolve 16, you can create timelines with frame rates that are different than the project. Regardless of the source frame rates, Resolve will render all the files in the sequence to the sequence settings. If your mixed frame rate source files skip frames or duplicate frames when they are edited to the timeline, this will be reflected in the output.

Rendering with a single clip is straightforward. Everything you see when you playback your timeline will be reflected in a single clip render. The exported file will match what you see in your timeline. The resulting video will be a string of shots with the timecode from your sequence not the source files with source timecode like the individual clip setting.

Frame Rates for Deliverables Rendering

The ability to create timelines with various frame rates in Resolve 16 is a huge help with finishing in Resolve. With great power comes great responsibility though. Creating many different sequences with all different frame rates can quickly become unmanageable for professional work. It’s still important to understand when to create timelines that don’t match the frame rate of your project. For things like creating standards conversions, for formatting your final edit differently, creating timelines with different frame rates is really helpful.

When it comes to finishing and deliverables, 23.976 is the most flexible option for working in Resolve. From 23.976, you can easily get to all the major delivery frame rates. In Resolve, working in a 23.976 project, you’ll have additional frame rate render options including 24fps and 29.97 when using single clip. Other project frame rates don’t offer these options.

Single Clip 24fps Options

Film Deliverables

24fps is a traditional film frame rate deliverable. When rendering to 24fps from 23.976, Resolve will slightly speed up playback. DCPs for theaters run at 24fps so if you’re editing video files in your project at 23.976 and want to convert to 24fps on your render, you can change the frame rate to 24 in the deliver page.

Since you can now add multiple frame rate timelines to your project, creating a 24fps master timeline is a better way to go instead of changing this setting on the deliver page. You can see and hear what’s happening with your playback before rendering if you have it on a timeline at that frame rate before rendering.

Broadcast Deliverables

When rendering from 23.976fps to 29.97fps, Resolve will add a 3:2 pulldown pattern during the rendering. Adding a 3:2 pulldown pattern is for creating broadcast deliverables at 29.97. You’ll see interlaced lines every few frames so this setting isn’t for creating anything for the internet.

There still isn’t an easy way to add 3:2 pulldown in Resolve without rendering a timeline in the deliver page. Adding a new 29.97 timeline in Resolve won’t insert a pulldown pattern into your video. But once you’ve exported a 23.976 with 3:2 pulldown to 29.97, you could bring it back into your project to QC within the same project as your 23.976 master. You could create a 29.97 sequence in your 23.976 project with the new timeline options. Then you could add your rendered deliverable to that sequence to QC on a broadcast monitor.

Standards Conversions

For any other standards conversions, you can create different frame rate timelines in Resolve. It’s still important to understand how Resolve will convert one to the other, but it’s possible to keep all those formats within one project now. In general, it’s a good idea to only make multiple frame rate sequences for deliverables. There usually isn’t a reason to create them during the editing process unless you have two completely separately capture camera footage with different base frame rates.

Conclusion

To parse down and recap, here are the major points to remember about workflow with frame rates in DaVinci Resolve:

  1. Shooting
    1. Playback frame rate matches your deliverable spec for post
    2. Sync audio or multicam clips need to match the project frame rate
    3. Write down or record all of the camera settings used
  2. Edit Prep
    1. Option 1: match source file frame rates to the project frame rate with clip attributes if you’re staying in Resolve for everything
    2. Option 2: keep all frame rates native so timecode matches the source file if you’re working with a larger team or multiple artists
    3. Add metadata of the native frame rate for option 1, the percentage metadata for mixed frame rates for option 2, and record frame rate for both options
  3. Editing
    1. Keep your re-timing to even multiples of 100 if the FPS speed matches your project
    2. Use the correct percentages or multiples of those percentages for re-timing non-matching FPS rates
    3. Use frame interpolation as a last resort for smoothing motion or for slow-motion effect shots
  4. Making Proxies
    1. Option 1: Create a mezzanine format and a matching proxy set with new timecode for finishing and color if you change the native frame rates to match the project frame rate
    2. Option 2: Create proxies that match the source file frame rates not the project frame rate
  5. Conforming
    1. Set your project to match the reference frame rate
    2. Make sure timecode and frame rate of the source clips matches the XML/EDL/AAF
  6. Rendering
    1. Use individual clip rendering if you’re not editing or finishing in Resolve
    2. Use single clip rendering if you’re editing or finishing in Resolve

You’ve made it through this incredibly lengthy article! Good for you! I hope it has helped demystify the workflow with frame rates in Resolve. Frame rates can seem daunting at first. There are many things that can go wrong with frame rates: non-matching timecode, stuttery playback, unexpected render issues. By working your way through this article, you can understand how to tackle these issues in DaVinci Resolve. Please leave any comments or questions below. Thanks for reading!

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Thank you to Dan Swierenga for contributing this article.

Dan Swierenga is a professional colorist and Flame artist with over 10 years of experience in post production coloring and finishing many feature films, shorts, documentaries and commercials in LA and Chicago. He is the co-founder of the post production blog ThePostProcess.com, a site dedicated to teaching post production skills and techniques.

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