Blackmagic output lag in a UHD comp

[chrisbrearley]

This has always been an issue. I was half expecting it to be fixed for the latest AE release but of course the devs have been too busy adding pointless 3D renderers rather than actually fixing the huge problems in the playback engine.

In a 25fps UHD comp the preview from the Blackmagic Intensity Pro 4k lags behind the main display by a huge amount, we're talking seconds here, not just frames and it gets worse the longer the preview plays for. No issues at HD and I get realtime playback in UHD with Resolve and Premiere so there's no blame to be put on the BM card, just AEs shocking Mercury Playback engine. This basically means that as of 2017 AE is still incapable of playing back UDH footage to an external monitor. Nice job adobe.

AE 14.0.1.5

Win 10

5930k

64Gb ram

2 x 980ti

[Szalam]

I don't know if this week's update (14.1.0) will help, but it's worth a try.

If not, please file a bug report (with as much technical information as possible). It will be seen directly by one of the After Effects engineers. They can't fix what they don't know is an issue. There are an infinite number of possible OS/hardware/footage configurations, so it's possible you've found a bug that's unique to a particular setup. That's why I suggest as much detail as possible.

[chrisbrearley]

Nah, exactly the same. I tried running directly out of one of my 980Tis as well. Better but still rubbish. Plays around 4-5fps behind and the image doesn't fill the screen either. Looks like it was outputting at 2560x1440 from the top right corner of the screen and filling the res of the screen with black.

[Szalam]

Darn. I didn't have much hope in the update for your issue, but there's always a chance.

Make sure you include the information you just mentioned in the bug report you file (link to the bug report form in my first post).

[chrisbrearley]

Tried it. Does anybody actually read them? I've also been in touch with tech support twice and Blackmagic tech support. Both companies blame each other.

[Szalam]

chrisbrearley wrote:

Tried it. Does anybody actually read them?

Yes! Bug reports for AE go directly to an AE team member and each one is read and cataloged. It is unlikely that you will receive a follow-up from a bug report, but it can happen and has happened. I've met some of the After Effects QA team members and they take bug reports very seriously.

chrisbrearley wrote:

I've also been in touch with tech support twice and Blackmagic tech support. Both companies blame each other.

It's frustrating when both companies blame each other, especially when the problem is often with both of them! Hopefully you'll be able to get things sorted out soon.

[Kevin-Monahan]

Hi ChrisBrearley,

Sorry to hear about this issue.

Both companies blame each other.

I tend not to do this. I usually do ask what the support team from the hardware company recommends. So what are they saying, exactly? Have you done a test for playback that did not include the hardware device? If you have a case number, I can talk to the agent "blaming another company" for your error. In my opinion, that's a poor way of supporting customers.

That said, I'm curious about this source footage. Which camera did it originate from? What if you transcode the footage? Still getting the behavior with a ProRes/DNxHR/Cineform clip?

Above all, please file a bug. We need more details to help you solve the issue as I can see no other cases reflecting your current issue.

I hope we can help you get to the bottom of the issue ASAP.

Thanks,
Kevin

[chrisbrearley]

Hi Kevin, thank you for your reply. I've spoken with two support agents

from Adobe about this issue and both suggested that it was not a problem

with AE but with the Blackmagic card. Unfortunately I don't have case

numbers for these conversations.

The source footage has nothing to do with this problem. In face there

doesn't need to be any footage in the comp. A 10x10 white solid animating

across screen will still lag. We are talking about playback from a ram

preview here so footage is a moot point. Playback on the main monitor is

fine, the issue is with how the mercury playback engine in AE sends the

image to the Intensity 4k. I have also unsuccessfully tried to use one of

my 980Tis as the output but again there are serious issues with anything

above HD. There is still lag and the image doesn't fit the screen

correctly. I would love to know if anyone has had any success in outputting

to an external monitor through any device with a comp size above HD.

I have filed several bug reports and feature requests over the years but

not once have any of them been acknowledged or actioned so I have given up.

I have been in touch with Blackmagic since and they have been able to

replicate the problem at there end. I am hoping that the engineers there

have a direct line with Adobe and are able to get there heads together and

figure out what is going on. This was a few weeks ago but I have heard

nothing since.

[Kevin-Monahan]

Hi ChrisBrearley,

Sorry for the delay in contacting you once more. Your response appears to have slipped by me, but I'm circling back now to see if anything positive occurred. Sorry for that.

Hi Kevin, thank you for your reply. I've spoken with two support agents from Adobe about this issue and both suggested that it was not a problem with AE but with the Blackmagic card. Unfortunately I don't have case numbers for these conversations.

I have tools that I can use to track your case down. I should be able to correct the issue from my side. That said, I need to find out where they are getting their info from, as there are no bugs logged here that I could find indicating the issue.

The source footage has nothing to do with this problem. In face there doesn't need to be any footage in the comp. A 10x10 white solid animating across screen will still lag.

Thanks for detailing the issue.

Playback on the main monitor is fine, the issue is with how the mercury playback engine in AE sends the

image to the Intensity 4k.

I have also unsuccessfully tried to use one of my 980Tis as the output but again there are serious issues with anything

above HD. There is still lag and the image doesn't fit the screen correctly.

I would love to know if anyone has had any success in outputting to an external monitor through any device with a comp size above HD.

See if Szalam's advice might help here regarding Display Preferences: Re: After Effects CC 2017 very laggy on second monitor

I have filed several bug reports and feature requests over the years but not once have any of them been acknowledged or actioned so I have given up.

That's frustrating. Sorry about that. Not all feature requests do get implemented, however, for a number of various reasons. I do not like that we don't acknowledge feature requests, but the answer to that is that we simply do not have enough time to do so for every case. We do reach out to select customers for clarification, though. So it does happen, just not very frequently.

I have been in touch with Blackmagic since and they have been able to replicate the problem at there end.

Thanks. Let us know if they follow up with any new info.

chrisbrearley 

I am hoping that the engineers there have a direct line with Adobe and are able to get there heads together and figure out what is going on. This was a few weeks ago but I have heard nothing since.

We have a standing relationship with all our partners. Since there is no bug filed from our side that I can see, and our partner is seeing a bug, I will have to reconcile that for all parties by filing by own bug. I'll see to it that it gets filed from our side. Any other info we could receive from you via a bug report would be ideal, that way, we can hit the issue from both sides.

Sorry again for this frustration, but I'll do my best to get the ball rolling on this issue. Thanks for keeping the communication going.

Kind regards,
Kevin

[Kevin-Monahan · Accepted solution]

Hey Chris,

I tracked down your issue and it is an issue we're aware of. I apologize for the problem. We are working with Blackmagic to improve the situation. Thanks again for filing your bug report.

This experience you're having is, more than likely, a performance limitation of Transmit. When frame sizes start getting into the UHD range, playback to the Transmit monitor can suffer. Since After Effects never drops frames, and Transmit output is asynchronous to After Effects’ internal playback, the slowed-down playback can get out of sync with the main monitor.

As I understand it, your experience with third party cards like the Intensity might even be less performant than using a high-performance GPUs to drive a second monitor.

From what the team tells me, this is a bandwidth issue. Performance can suffer by adding larger frame dimensions, higher frame rates, and deeper colors to the playback stream.

You can mitigate the issue by doing some of the following:

• Make sure the Hardware Accelerate Composition, Layer, and Footage Panels option in Preferences > Display is enabled, especially if color management is enabled for the project. Disabling color management or setting the working space to Rec 709 can also help.
• Reduce the comp resolution, either in the Preview panel (i.e., per-preview shortcut) or the comp viewer panel.
• Enable the Skip option in the Preview panel so that fewer frames are being previewed.
• Reduce the project color depth.

It's too bad that I can't come up with a better solution for you at this time. For that, I apologize. If others are facing the issue, be sure to file a bug so that we can make improvements along with Blackmagic.

Thanks,
Kevin

[JayFriesen]

I filed a bug report. I'm having the exact same issue on a BMD Mini Monitor 4K with a UHD comp. Results remain the same regardless of setting changes or content.

[ryanBS]

I know this thread is old, but unfortunately this is still a problem.  My problem is a little bit more specific.  I only get a lagging, stuttering playback on external montior if Color Management is enable.  If its disabled, everything plays normally.  

Has this problem ever been solved?