4k dynamic link AE comp scales down in very poor render quality (jagged edges) when exporting in HD

[Heiko-Brantsch]

I'm usually working with 4k+ footage so in order to match the source resolution, I have also created all motion graphics comps in AE in the same resolution.

It all works without issue when rendering everything in AE to ProRes files and working with those in Premiere.

However, when working with dynamic link clips instead, I get extremely poor scaling results when exporting in 1080p (see attached screenshots).

My current workaround is exporting my Premiere Sequences in full res first (that works fine with dynamic link) and then converting my full res exports to HD later. But with a fast turnaround for client feedback, these extra steps get annoying quickly.

Shouldn't dynamic link clips be able to be downscaled to HD with the same quality as it would when rendering those comps in HD from AE directly?

I'm working on the newest Version of both Premiere Pro and AE and I've tested this on both an iMac Pro and an M1 Macbook.

[R Neil Haugen]

Do you have Max Render Quality selected both in "preview" and the export dialog? That forces high-Q rendering most noted in diagonals.

[Heiko-Brantsch]

Thanks for the suggestion, yes I have. Premiere has no trouble scaling down the graphics when I import them into premiere as ProRes 4444 with alpha. But with the same graphics linked as dynamic link clips I can't export to a lower resolution without getting terrible aliasing. Maximum Render quality was always checked in all of my renders testing this issue and I've been coming back to this project for weeks, the problem still persists. Only usable workaround is to render at the original resolution and downscaling them to HD with AME after the fact.

[R Neil Haugen]

That's something that a more qualified Ae expert would probably need to help with. @David Arbor  ... or a staffer ... @mattchristensen  ?

[David Arbor]

 Dynamic Link has a lot of mysteries under the hood (at least to regular users like us), so I'm afraid I don't have any insight into this one. I often perform a Render and Replace when I'm done with a comp anyway since rendering or exporting my timeline always slows once the DL clips are hit.

It doesn't sound like you're doing this, but the first thing that comes to mind that could cause this is if the Preview Settings in your Premiere sequence settings dialog are set to a lower resolution, you've rendered your timeline, and then check the "Use Previews" box while exporting.

[Shebbe]

I remember wanting to post about this. We used to do some projects where inscreens where comped onto a plate but keeping everything quick to adjust we used the plates only as guide layers in AE and dynamic link the composite to PR with only rendering the inscreen itself. Especially for offline editing this is practical because playback for camera files is simply much faster directly in PR. But we quickly realized that Dynamic Link scaling is pretty messed up as you show here and we comp in camera res instead of delivery res because that's simply how compositing is done best.

From my own judgement it looks like Dynamic Link scaling uses nearest neighbor or some other non-practical but perhaps cheap to render scaling algorithm which doesn't match the one PR or AE uses. Inside AE you have 3 options (which aren't even named for the user but I guess you can classify them as linear, nearest neighbor, and sharper).

What you perhaps could do is put the native res comp into an HD comp inside AE first and use that as the dynamic link clip. Not perfect but would allow linking instead of rendering out first.

Adobe has a long way to go in this regard. IMO they should throw away the Max Render Quality stuff. Scaling needs to be it's own dedicated management on both AE and PR so the user can have proper control over it similar to how Resolve and other apps handle it. And image processing should always be 32bit which I believe it isn't if that box isn't checked. But unless you have some odd reason not to want this I think all current day machines are more than fast enough to handle this.

[R Neil Haugen]

Totally agreed they need to rebuild this part of the app.

Premiere uses Lanczos scaling, I believe. Which supposedly in their testing works best for most images. Though many experienced users disagree.

[scrozier]

Just want to jump in and say I have never seen this before until today, and wow its a nasty bug or issue. 

Had a 5k drone shot I did some quick paint & roto in and when I brought it into premeire and scaled it to 40% the diagonal lines on the building looked like like a little staircase. 

I fixed it by pre-comping the AE comp to 1080 and bringing that in but I don't know why AE comps are scaled like this when no other footage item is. I think they probably did it as an optimization to make Mogrts render faster a few versions ago and this is a bad side effect. 

Ugly jaggies! Scale 5.1K drone to 1080p. AE Dyanmic link. 

No jaggies (original shot in timeline) 5k scaled to 1080 .mp4 file.

I'm glad I caught this before shipping!  Yeah the workaround seems to be to Do a pre-comp and scale before bringing it into your timeline but I can't ever remeber having this issue before. Setting high quality playback or maxQ doesn't do anything, and rendering it in the timeline also keeps the same bad quality. Not sure about final export. 

[R Neil Haugen]

Wowza.

[the_dudes]

This is still here and should be filed under [BUGS] by adobe 😡

[the_dudes]

Hi Heiko, here's what worked for me:

- Have 4K video footage in a 4K timeline

- Have FHD dynamic link AE motion graphics

- Set clips in time line to be "Scaled to Frame Size" and not set it to framesize (=200%)

- I got proper scaling this time.

Hope this helps.

[Heiko-Brantsch]

What? You got usable results withs "scale to frame size" rather than "set to frame size"? That is very curious I need to try this and will report back.

I never would have guessed "scale to frame size" actually scales anything different under the hood!

I always always use "set" because I need to know when I'm above or below 100% of the source res, because I usually try to never upscale anything beyond 100. So it's possible that "set to frame size" is causing the issue not scaling in general.

The weird problem with this is I wasn't even scaling up anything. I was scaling *down* from 4k to HD. Scaling down footage never caused me any visible quality loss in any software. Except with dynmic link clips in Premiere.

[the_dudes]

It's wicked. Always some misteries with software I guess 🙄 Lemme know how it went!

[Kevin-Monahan]

Hello @Heiko-Brantsch, @the_dudes, @R Neil Haugen, @scrozier, and @Shebbe,

Thanks for providing all the information, guys. We need product team involvement on this thread. Does this look like new behavior? It sounds like it.

@Bruce Bullis - who should we get to look at this issue?

I hope the team can help you with this scaling issue soon.

Thanks,
Kevin