4K video in HD timeline == 4K output?

Just want to make sure.. I import 4K video (DNxHR SQ 4K), but I have HD displays, and I am guessing it defaults to a 1080P timeline recognizing my screen resolution. When I render, I select YouTube, then change the resolution to 4K. I want to make sure it is using the source 4K in the final output, and not upscaling the 1080P timeline into 4K. I would imagine that is how it works, but just wanted to be sure.

The timeline is whatever you want it to be. How you monitor doesn't necessarily change the timeline resolution. You can still have a 4K timeline with 4K source material and monitor in HD. If the machine starts getting sluggish, then I'd change it to an HD timeline, work in that, and then switch everything back to 4K when you finally render the entire project out.

So I am a little confused. Do I need to go into prefs and switch the timeline to 4K in order to render 4K? Currently in the delivery tab, I select the youtube option, then I manually change the resolution to UHD. Does that not properly render a 4K file? It seems to.. and when I upload to youtube, eventually after some processing 4K is an option.

I think it's safe to say that in this respect, the timeline in Resolve works as in most NLE's, i.e. the settings dictate the resolution and frame rate of the processing, rendering and output of the timeline itself, regardless of the resolution of the original files.

You can scale the monitor output, using a resolution different from the timeline, and it won't affect the quality of the timeline output.

In the delivery tab, you choose the container, video codec and audio settings for the file(s) you wish to export, and as a convenient option, you can choose to export a resolution different from what the timeline is set at, but this means that the timeline resolution is scaled to the export resolution you choose.

The actual resolution of the exported file is limited by the timeline resolution setting, so if you use 2160 footage in a 1080 timeline and then set the export to 2160, the exported file will be 1920x1080 resized to 3840x2160.

Oh wow.. that does make a big difference! I didnt know that. So is it OK to use a 4K timeline using a 1080P monitor? I am guessing so.

That is not what I expected. I assumed that the timeline is for arranging clips. Why would Resolve, when rendering the final output, not use the actual 4K source.. and instead use the timeline that has I am assuming in real time (during render?) convert the 4K source to 1080P, to then resize/scale it back to 4k? That just seems like a huge processing waste of time (or is it?) as well as if you select the same output resolution as the source, regardless of the timeline, you would think it would just use the source directly?

You could say that the actual 'processing' is done in the timeline, and for most effects/transitions/overlays etc to work as expected the media involved need a common fps, aspect ratio, resolution and colour gamut. This is really what timeline and project settings are for.

Changing the export size is ok for downrez deliveries, but not always optimal.

I get that..makes enough sense, just seems a little off.. but I see how there is the option per clip to use source resolution, etc. So perhaps the right way to look at it is the more common scenario is to use the timeline as the processing output, and the delivery is same/upscale/downscale based on timeline output?

Page 1215 of the user manual explains the use of output and rendering options.

The most common procedure is to just change the timeline resolution before final output. However you CAN output 4k from an HD timeline, but it's wise to do a test to satisfy yourself that the image quality is acceptable compared to a 4k timeline render.

Keep in mind that rendering individual clips allows both timeline resolution and original clip resolution output options.

Screen Shot 2017-10-24 at 12.18.28 PM.png (579.25 KiB) Viewed 20118 times

The most common procedure is to just change the timeline resolution before final output. However you CAN output 4k from an HD timeline, but it's wise to do a test to satisfy yourself that the image quality is acceptable compared to a 4k timeline render.

You can, but it's a bad idea. It is possible to use 4K material in an HD timeline and literally go from 4K -> HD and back to 4K, which will not look as good as 4K -> 4K -> 4K. I speak from experience: I once accidentally did this about 5 years ago, but noticed one reel had some extremely soft shots. When I set the timeline to 4K, all was well.

As we often say in post, "if you catch it before it ships and before the client sees it, then it's not a mistake."

From the Resolve 14 manual, page 1222:
‚”Use optimized media: When this checkbox is turned on, DaVinci Resolve will use optimized media, when available, to do the final render, to save time. If your media has been optimized to the same format as the one you’re outputting to (or better), this is convenient. However, if you’ve optimized to a lower quality format than what you’re outputting to, you should turn this checkbox off to force DaVinci Resolve to process all clips using the original media, guaranteeing the best quality available.
‚ Use render cached images: When this checkbox is turned on, DaVinci Resolve will write media from the cache to the files being output to save time. If you’re caching using the same media format you’re outputting to (or better), this can be convenient. However, if you’re caching in a lower-quality format than the one you’re outputting to, you’ll want to turn this checkbox off to force DaVinci Resolve to process all media as it’s being rendered, writing at the maximum quality you’re outputting to.”

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Now with those buttons turned Off and the Advanced buttons turned On, I’ve interpreted this to mean Deliver goes back to the Source media (which I thought was the original media). You guys are the experts, but that’s the way I’ve thought raw was handled. Is everyone saying the Source is the Project timeline? In my mind Source means original and why wouldn’t it say Timeline if it’s using media as defined on the Timeline?

There’s a Source Viewer and that’s typically used when you drag your original media into it for viewing or selecting In and Out points. It’s called the Source Viewer, no? It’s not called the Timeline Viewer. Anyway that where I’m coming from.


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Where are the options in Resolve 14 to enable optomized media? I see the option in Project Settings for Optimized Media in the Master Settings section, but I dont see anything regarding enabling or disabling this?

In the Project Settings you define the characteristics of the Optimized Media you will generate. Then you can right-click on one or all of your original media in the Media Pool and select the action item Generate Optimized Media. Voilá!


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Well shoooot.. learning something new every day! I thought with it set to auto it would do that anyway. Though, I do have optimized video set to 4:2:2 10-bit, same as the source at DNxHR SQ.. so not sure if it does anything or not?

If you leave the resolution the same, I don’t think there’s any need to optimize DNxHR. I think that’s already considered optimized. Often one uses optimized media such as ProRes when the original media is raw.


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Now with those buttons turned Off and the Advanced buttons turned On, I’ve interpreted this to mean Deliver goes back to the Source media (which I thought was the original media). You guys are the experts, but that’s the way I’ve thought raw was handled. Is everyone saying the Source is the Project timeline? In my mind Source means original and why wouldn’t it say Timeline if it’s using media as defined on the Timeline?

Optimized Media is just used for playback to get the performance up. For a final render on the Deliver page, it'd go back to the original media. I wouldn't ever want to use Optimized Media for a delivered file, because it's going to look crappy. I'm actually not a fan of Optimized Media for a lot of reasons, but I concede that it's necessary if you've got big files on an underpowered machine and you have to get by somehow. And I've done it before.

I've been aware of this for a while, but I REALLY don't think this is the way it should be going forward.

I enjoy the benefits of shooting 4k+ footage and then editing in 2k/HD. It's effortless to punch in to 1:1 to check stuff as needed and with my dual 2560x1440 monitor setup an HD resolution timeline is a good fit (regardless of 4k performance).

Since Resolve is resolution independent we can change timeline resolution at a wim and keep all windows and so on—which is great—but I really think this functionality should extend to an awareness of the source material vs timeline vs export dimensions.

Obviously aspect ratios need to be maintained and one needs to keep the scaling options in mind such as "fit whole image" or "crop to fill", but Resolve should perform the equivalence to a manual timeline resize when exporting high resolution footage to a smaller output file.

NOTHING else makes sense.

This is how I, and I'm sure many, many, many with me, assumed it worked until I read otherwise (and sprayed with monitor with coffee in a knee jerk WTFH reaction).

Please fix. Or stop talking about "always going back to source footage to maintain quality", which I've heard Mr. Van Hurkman say in numerous videos.

While there's definitely a place for downrezzed file export, utilizing the current rendered scenes to save time, unintentional uprezzing can (and will) happen to anyone, newbie or seasoned pro.

Dynamically adapting the timeline resolution to the current export setting is not a solution, as some project/timeline parameters need to be somewhat 'static' for a multitude of reasons. (caching, rendering, aspect ratio etc)

To fix this issue, I suggest a new user setting checkbox:

x Limit export size to current timeline resolution or lower.

I'm having an issue in that I'm grading a 2k timeline and monitor in HD.

It seems to me, if I remember, back in Resolve 12.1, when I set the timeline to 2k and the display output to HD23.98fps all was well.

Now, in 12.5, when I do this the image shifts to the side and I don't see the entire 2k image scaled down to HD in my display.

To fix this, I need to set the output scaling to HD also. And this means I must be careful to undo this setting prior to the final render. And this is a concern as the final render will be done on the other side of the planet from my .drp projects. I am concerned that the render person will not know how to re-set the settings for proper rendering to 2k.

Is this a bug? I noticed the same behavior in V14.

I'm using Windows 10, Ultra Studio 4k decklink card.

Thanks, Marc, Andree, Johan. I didn’t spill any coffee on my keyboard over this, but I was frustrated and somewhat irritated that this uprez from the Timeline resolution still existed. This was discussed a few years ago in term of the BMCC and the BMPC4K as I recall. Totally agree with Marc that Optimized Media is only to improve Edit/Colour Page performance and not the generation of deliverables. My mistake was thinking that the Source resolution used to generate my deliverables was determined by my original raw footage and not the Timeline which I can’t run well at 4.6K on my iMac. Lesson learned.

I like the suggestion to improve the options and the documents that refer to Source as the Timeline when it appears other folks also thought Source meant Original. Feeling better now so thanks for putting up with my ignorance on this.

In the future where my Timeline is smaller than my Original, when I have completed everything else, I’ll change the Project Settings for Timeline resolution to match my Original raw files and then go to Deliver where I’ll turn Off the Optimized Media and so as previously described.


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