Blackmagic Forum

Let's say you work in a 4:3 open gate timeline. Grading is done with respect to the 4:3 aspect ratio. Then you nest this timeline into a timeline with a different aspect ratio (let's say Scope). Ideally you would set it to "Full Frame with Crop" only crop away on the top and bottom.

Every clip that has been reframed with the input sizing controls in the color tab, will now behave incorrectly. But not only sizing is affected by this issue, but power windows aswell. Roto, masks, whatever are now completely offset by a certain percentage.

It looks like that percentage is tied to the mismatch of the resolutions. Meaning if there is a height difference of about 80% then the masks will be off by 80% aswell.

This is a crucial flaw that needs to be addressed.

One use case of that workflow is, when you need to do multiple deliveries in different aspect ratios (for example for social media, TV, and cinema). Or if you have pre-rendered text elements and graphics (in the final delivery resolution) that you don't want to unnecessarily scale up to the resolution of the grading timeline - only to scale them down later again.



Using Resolve 18.1.3

Is it possible for you to post a link to a short project archive for someone to take a look at? Could be that the scaling choices are leading to this issue. Not that it isn't a bug, but it could be that a different set of choices could yield acceptable results.

Steve Alexander wrote:Is it possible for you to post a link to a short project archive for someone to take a look at? Could be that the scaling choices are leading to this issue. Not that it isn't a bug, but it could be that a different set of choices could yield acceptable results.

I can try that later. But I already went through all the options.

Found a little workaround, but still not happy with this bug.

Essentially you should create the second timeline with the same aspect ratio, but only do the sizing (from open gate to delivery). After that in the output scaling you can crop the image to the new aspect ratio. Depending on which way you go, you start with either the width or the height for the resizing.


It's as I said, a workaround, but it get's the job done at least. BMD should still investigate into this.

Yes - that's similar to how I do it as well. Essentially I keep the timeline resolution the same for all the timelines and then play with the output resolution. I use the no size, no crop on output to take full control of the composition as well. Not everyone's cup of tea, but it seems to work with only a few minor hiccups. I do the same when going from horizontal to a vertical composition. These are workarounds to be sure, but I've become accustomed to them. It would be better if Resolve did this automatically (under the hood), I suppose.

Steve Alexander wrote:Yes - that's similar to how I do it as well. Essentially I keep the timeline resolution the same for all the timelines and then play with the output resolution. I use the no size, no crop on output to take full control of the composition as well. Not everyone's cup of tea, but it seems to work with only a few minor hiccups. I do the same when going from horizontal to a vertical composition. These are workarounds to be sure, but I've become accustomed to them. It would be better if Resolve did this automatically (under the hood), I suppose.

I do that aswell, but you don't have any conteol over the resizing filter that way. Clip based adjustments may not do anything, because input won't get scaled. So you are bound to the project wide setting, wich might not be ideal for everything.

That's why I wanted to work with a nested timeline in the first place. Graphics will be added on top in that second timeline, where I now can control their filtering

Sven H wrote:Every clip that has been reframed with the input sizing controls in the color tab, will now behave incorrectly. But not only sizing is affected by this issue, but power windows aswell. Roto, masks, whatever are now completely offset by a certain percentage. It looks like that percentage is tied to the mismatch of the resolutions. Meaning if there is a height difference of about 80% then the masks will be off by 80% aswell.

Unpopular opinion: don't do that.

My tactic for workflow in multiple resolutions is this:

1) export a flattened textless render in full-res for the entire show, using a visually-lossless codec like DNxHR 444 or ProRes 444.

2) create (let's say) three separate projects, each in its own aspect ratio.

3) import the flattened full-res file to each project, make the project settings identical to delivery (vertical for social media, pan/scan for 4x3, whatever you're doing) and reframe as necessary. Position text in a way that's optimized for each format.

4) within each project, add the timeline to the Render Queue. Now, using the Option ("3-dot") menu, Show All Projects, and you can kick off all the renders from a single project.

5) upload the final renders to wherever they need to go -- Broadcast, Snapchat, Facebook, YouTube, whatever. Done.

We've used this workflow for a couple of years now and it solves many problems. We avoid nested timelines for many problems (particularly audio), and we also avoid mixing aspects within the same project with the possible exception of documentaries, which are kind of a specialized case. Many, many documentaries use 1.33 archival footage, and it's an ongoing discussion as to whether we present that in the original aspect ratio, or blow it up for the new show aspect ratio, or if we go somewhere inbetween. I can make each argument convincingly, but it's a create call. We change sizing as a Timeline Sizing-only grade with Static Keyframes, and it works perfectly. If we had to deliver in multiple aspect ratios, it might be tricky but doable with some work.

Nested compositions need to work properly. I'm creating a show for an on-stage event with many screens in different resolutions. I build each screen in its own timeline, then bring those into a "previs" timeline to show how all those screens will look together on stage. Some of the screens need to be split and rotated and re-assembled in several tracks, then nested into the previs timeline as one single track.

But if a nested timeline is a different aspect ratio, or even if one of the clips USED in the nested timeline is a different aspect ratio, things don't align properly in the previs timeline. Unacceptable.

Premiere can do it. Resolve must fix this.

davidcodeglia wrote:Resolve must fix this.

It would be nice.

But it's been a problem for a while. You probably shouldn't count in this being fixed to do your project.