Annoying background flicker (intermittent)

Hi, ever since updating to 10.4 I am having an intermittent problem with a strange flickering effect. As I say it happens on some clips and not others, doesn't show when playing back clip in inspector but when put onto timeline it shows up. Sometimes closing the program and restarting fixes it. Sometimes deleting clip and putting back fixes it, sometimes it only appears when adding any colour grading. Very strange and very time consuming.

Has anybody encountered this?

Below is a quick demo of the problem, same clip from different timelines with same grading/colour correction.

FCPX 10.4
iMac (Retina 5K, 27-inch, 2017)
Processor 3.8 GHz Intel Core i5

Wouldn't call it 'flicker' , which is a typical unwanted side-effect using LED lights or 60fps in a 50Hz environment …

What I notice, for example in the subjects shadows, are compression artifacts – so, my verdict is: did you incidentally exported a Proxies version? …

Yes, what Karsten said, but he beat me to it. Those are defilingly compression artifacts.

Thanks Karsten. Are you asking if I "accidentally" exported or imported a proxy version? I never use transcoding when importing so none of my files are proxy versions so surely I can't export a proxy version.

As I say the problem is very intermittent, it happens sometimes to some files and then the same file will work and perform perfectly fine on another occasion. The artefacts are not there when viewing the files via the inspector, the anomaly can only be seen when on the timeline itself.

It is driving me crazy, not updated to High Sierra btw. Only had this problem since updating to 10.4.

DanWhitehead76 wrote: … happens sometimes to some files and then the same file will work and perform perfectly fine on another occasion. The artefacts are not there when viewing the files via the inspector, the anomaly can only be seen when on the timeline itself. …

hmm, difficult to narrow the culprit if it occurs randomly.

again, for me (and Ben) it looks like a compression misbehave … so, you're not using Proxy, … the en/decoding has to happen on-time, so it could come to 'hiccups' … What about switching the Preview Window settings from Better Performance to Better Quality (to the price of missing frames)?

Do those 'blurs' happen in the final output?

Final Q: Is your source material from a camera? What res/fps/bitrate? …

I think nail on the head with the word misbehave. All fine one minute and then it suddenly decides to add these artefacts, usually when I do some colour correction or changes in any way but sometimes it just occurs moving from inspector to timeline.

I have tried changing the preview window but no difference, plus recently upgraded Mac so have a 2tb fusion drive, 16gb Ram on a 5k 27inch i5 Mac and a Radeon PRO 580 graphics card...surely the performance should be able to handle most of what I throw at it?

Okay I think I may have found the cause but no idea why this is happening, especially only occasionally.

Full disclosure. I import 4k 25fps native video into FCPX. I then downscale on a 1080p 25fps timeline using Apple Pro Res 442 codec. Is this where the proxy version is created? I thought you could only create proxy version on import?

Anyway, on testing, when I create a new project using uncompressed 10bit 4:2:2 codec the anomaly doesn't seem to appear. In fact copying the misbehaving clip from one project onto the uncompressed project removes the problem.

This is good news however I still don't know why it is happening and why so intermittently. Have always used this method when editing but only had this issue since upgrading to 10.4

You can also generate proxy (or optimized, for that matter event after you imported and have second thoughts): select the clips or the event, CTRL+-click or use File and select Transcode Media. A dialog box appears that lets you create proxy or optimized media.
support.apple.com/kb/PH12702

What is the source of the clips? What camera/codec?

Clips are 4k XAVC S AVCHD from a Sony A6500. I believe the compression is MPEG4. Quite new to shooting with a Sony mirrorless so not sure if any of this has any bearing. As I say though not had problem with the camera, compression, codecs creating this problem before. Whether it is related to 10.4 I don't know but can't be a coincidence? Has 10.4 changed the way my files are compressed into FCPX?

Unless you click Optimize or Proxy during import, your clips don't get "compressed into FXCPX", they remain native.

FCPX 10.4 does seem to have some issue with AVCHD clips, but normally during import.

On that subject, I wish FCPX would be more transparent on whether it's re-compressing or just re-wrapping incoming XAVC files. I totally believe FCPX.guru that they aren't being compressed, but it is a bit disconcerting to not be able to select "leave in place". It sure looks like it's copying the files (with the new wrapper) into the library and thus duplicating all the footage. Oh well.

Sorry about the OT. As far as the OPs problem, I can't think of a good solution other than converting the files into Prores first and that's painful (from a file size and time standpoint). We shoot with a Sony A7S II sometimes as a B-camera (or with gimbal) and its XAVC files aren't AVCHD so it's a different animal.

The only time you can't Leave In Place is when ingesting from a card, which makes perfect sense to me. Why would you want to leave originals on an SD card and edit off of it? Just my opinion. And yes, this is getting off topic.

AVCHD is buggy in 10.4, Optimize it when ingesting.

Hello Den! I have exactly the same problem, I already pulled out all my hair! How did you eventually solve the problem?
Thank you!

DanWhitehead76 wrote: Hi, ever since updating to 10.4 I am having an intermittent problem with a strange flickering effect. As I say it happens on some clips and not others, doesn't show when playing back clip in inspector but when put onto timeline it shows up. Sometimes closing the program and restarting fixes it. Sometimes deleting clip and putting back fixes it, sometimes it only appears when adding any colour grading. Very strange and very time consuming.

Has anybody encountered this?

Below is a quick demo of the problem, same clip from different timelines with same grading/colour correction.

FCPX 10.4
iMac (Retina 5K, 27-inch, 2017)
Processor 3.8 GHz Intel Core i5

Please avoid FullQuotes
The Grumpy Board Janitor …

Hi guys, i think i found the solution! You need to use "Override Color Space" in the "settings" of the Inspector (select the all source media in library) and switch to Rec.709. It's problem AVCHD

Yes, Yes, Yes....hope haven't spoke too soon but that looks like you have cracked it. Thank You so much. I thought I had found a workaround. Created new user for recent project and imported optimised instead of native. Things seem to have worked doing that but didn't want to count my chickens too soon.

However going into other profile and opening one of the past projects that had this issue and changing that colour space setting, it fixed the clips immediately.

Guessing as others have said that on import the colour profiles are not set to Rec 709 for AVCHD when importing native video. Definitely something that has altered since the 10.4 update. Thanks again.

See MNXA solution, seems to have worked for me. Good luck