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25 Jan 2021
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Untreatable Flicker..? 03 Dec 2022 14:56 #123168

Hey FCPX pros!



This last week I’ve been working with someone from the US (I’m in Sweden) on some video material.

The problem:
- The footage, when brought into FCPX, starts flickering. See video example on Frame.io here. 

What I’ve tried:
- Adjusting the timeline to match the frame rate of the original footage (from 30 -> 24) — no difference
- Anti-flicker plugin that does the 50% overlay method for you — works, but makes movement in the shot unnatural and audio gets more unsynced

The person I’m working with has used this same recording/lighting setup for other videos without any flicker. It also isn't noticeable before being brought into FCPX. It only seems to occur with me and in FCPX.

As you can see from the video , the flicker even occurs if I pause the video while using the Anti-flicker plugin.

Is there any way to solve this? What might be the root cause?

Kindest regards,
Tim

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Last edit: by timgabe. Reason: formatting looked weird

Untreatable Flicker..? 03 Dec 2022 15:38 #123169

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There was a problem long ago whereby FCP could intermittently mis-identify the color space and it would cause unpredictable flicker. Supposedly that is long fixed and I haven't seen it in five years. However try selecting the clip, then in the Inspector pick the "Settings" view at bottom, then in Color Space Override, pick Rec. 709. That was a workaround for the previous problem.

If you can upload a brief test clip to DropBox, etc. showing the problem I can examine it on Resolve Studio, Premiere and FCP on both Apple Silicon and Intel. You can also put the file in this write-only DropBox folder: www.dropbox.com/request/ldvOOdRDizVtDXcpCdpG

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Untreatable Flicker..? 03 Dec 2022 16:04 #123171

thank you so much for this, Joe.

I uploaded a test clip to the dropbox folder 👌 let me know if you need anything else -- it's really immensely appreciated.

for some reason, I can't see the settings view you refer to with the Color Space Override. is this the menu you're referring to?
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Untreatable Flicker..? 03 Dec 2022 16:45 #123172

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It appears to be the same problem as 5 yrs ago. FCP is somehow intermittently mis-identifying the color space. It does not happen on Resolve Studio 18.1.1 or Premiere 23.0.0.

This does not absolutely mean it's an FCP bug, although it might be. The MP4 is not a camera file but is apparently written by the x264 library, maybe from OBS, Handbrake, etc. The file metadata shows 41 different encoding parameters were used. In such cases some standards violation may happen, or the encoding library uses some grey area of the encoding spec. Then downstream utilities whether a NLE or anything else may behave unpredictably when processing those files.

The workaround is manually set the FCP color space override to Rec. 709. That can be done for all imported clips in a single batch -- just select them in the Event Browser, then set the override.

That is in the Inspector's "Info" tab (the little "i" at the top), but it's only visible if the Inspector view is "Settings" (the pull-down menu at bottom left of the Inspector pane). Select all clips then set Color Space Override to Rec. 709. After that it should be OK.

There might be cases if render files, proxy files, etc were already generated those might require regenerating, else the problem could be already encoded in them.

I tested this on FCP 10.6.5, Monterey 12.6.1, Apple Pro Video Formats 2.2.4, M1 Ultra Mac Studio. It also happens on Intel, so it's not unique to Apple Silicon.

Other characteristics: it happens whether using Better Quality or Better Performance playback, also whether using original or optimized media.

If you approve uploading that clip to Apple, I can file a bug on this. They can determine if the problem is within the clip or if it indicates an FCP issue.

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Untreatable Flicker..? 03 Dec 2022 17:27 #123173

that's just so much more help than I could ever expect to get. thanks again, Joe. you solved this for me!

and yes, you're right -- the video is recorded in an online podcasting software.

I've contacted the client to check if they're ok with uploading the clip. will get back to you ASAP. 😊

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Untreatable Flicker..? 04 Dec 2022 04:27 #123174

we're good to file a bug with this material, Joe!

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Untreatable Flicker..? 04 Dec 2022 10:17 #123176

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OK it's filed as FB11848829.

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Untreatable Flicker..? 05 Dec 2022 13:10 #123194

wonderful! thanks again. will be interesting to see what they conclude. 😃

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