Final Cut Pro on Three 4k screens UPDATE! AKA dual display bug fix.

Ok kids, so I figured it out, SmartSound SonicFire-Pro was the culprit, I don't know why or how, only that it was the one holdover app from 2006 I was still using up till 2014 or so to generate music for some productions I was working on that no longer exist. I deleted that app and all the supporting files out of the system, and now A/V Output works as it should! Who knew?

@Joe Redifer, that is what A/V Output is designed to do, select a target screen and go full, no menu, just pure video play back, when it works, it works! And now it is working for me, d@#m that took way too long to figure out!

Sadly, I must report back, FCP updated to 12, and now I am right back where I started. FCP loads up with A/V Output on, and right back to half screen on the edit window again!

When set to A/V Output, I get this familiar screen, the attempt to A/V on itself 1/3rd screen, back to its old tricks! Welp, pop open display settings, fiddle with resolution, fixed. Guess I just live with it! Time to dig into FCP 12!

So yes, the Samsung is always set to 4k (3840 x 2160), but when you target that display for A/V output, FCP never just works in that way. In fact, ever since I moved over to FCPX back in 2015, it's never just worked on any screen for A/V output for me. it always attempted to launch on the edit screen itself, and then I had to force quit the app. This is what has happened when I launch FCP and then set A/V mode.

See how the left 3rd of the screen is now occupied by the video? That is the right 3rd cut off attempting to playback on the self same screen.

So again, to fix, I go into displays, set the resolution to something else, and the video magically pops into the Samsung.

See it's set to 4k normal, so I set it to 3360 x 1890 for a second, screen pops up, then I set it back, all is right with the world.

This has to be done each time I want to use the A/V output on FCP, I'd rather use the player breakout, depending on what startup cycle I am in, it either launches into one of the 2 Studio Displays or it launches into my Samsung. That's the other really strange bug that has never been fixed.

The system switches desktops, I track this with a png file I have placed on the desktop, when I reboot and that file shows up on the Samsung, then I am good to go with Viewer in the secondary display, as I know it will send it to that screen. When I reboot again, and that png file shows up in the other screen, that is where the secondary display will be for that cycle.

What's odd is that the system does this, but keeps the orientation of the screens, so I have them from left to right, the system keeps them in that order, it just swaps the secondary display. A bug I have had ever since I got 3 screens and my M1MAX silicon MBP. But, I seem to be the only one with this issue, it's annoying to say the least, but I deal with it, part of the reason I updated my OS to Tahoe, wanted to see if they fixed it. Not sure anyone is aware of it. Probably some stupid app I installed that I used back then that's giving me a headache that no one else uses! That is usually the case.

As a test, I set the target display to my other Studio Display that is set to default 2560 x 1440, same thing happens, the video attempts to fullscreen on the screen that has the app running, with settings open, I select 2880 x 1440, A/V pops into the 2nd Studio Display. Set it back, off to the races. Such an odd bug!

Luis Sequeira1 wrote:

Sorry to hear that.

Just yesterday I tested by attaching to 1080p displays to my MacBook Pro, and it worked without issue, allowing me to select either of them as AV Output and using the other as secondary display, so I still think there is something in your setup causing this...

Perhaps you really ought to do that clean install. It is not such a big deal these days, it can be done in very little time.

1) Full backup (preferably two)

2) System Settings->General->Transfer or Reset->Erase All Content and Settings

3) Migrate your user accounts (do NOT migrate everything, otherwise you'd get back to where you started).

4) Reinstall any applications from the App Store or their developers' sites

That's it. To be sure, in step 4) I'd install FCP only and test, then gradually install whatever is needed, and keep testing to see if anything causes it. My expectation is that the issue may not recur at all, as probably what causes is something that you don't need.

Ok, so I am constantly working, and this issue, while a pain, isn't in the top category as to wipe and start over, which I literally did when I went from from my MacPro Trashcan (2013) to my M1MAX, I cheated moving to my M3MAX. I think the solution is going to happen when I purchase my next system, an M5MAX what ever, and JUST install FCP with all its plugins. OR, I might just get a MacMini M5 for a test bed. For my daily driver? I need it to be all there when I need it, flaws and all for the meantime.

And it's not that easy to rebuild your computer, there are things you do to the system over the years that you forgot you did that are quality of life additions. Some things you used Terminal for, I sure don't remember all the command lines I've added, all I know is when I did the major transition into Silicon, I had to stumble on those oh yea, I did that thing and it took a few weeks to get the system back into shape after the initial install. It's a bit of commitment.

I forgot about Etrecheck, had to update it, sadly, the only major issue it came up with was that it had been a while since my last Time Machine backup! I do it about once every 2 weeks if I remember to do it. The outdated apps are from Steam, back when I let my kid use my computer to test out games, I guess I can remove all that now. Nothing jumps out as something that would do all that I am experiencing. I do run espresso displays, but I need that for when I am remote working, and this issue predates my espresso displays. You are right, this problem has spanned over a few systems, MacPro tower, the MacPro they put in the G5 grater (this might have been FCP7 at that point, can't remember), the trashcan that I used up till they released the M1MAX MBP, and then the M3MAX MBP. It's fine the way everything is atm, I have a solution to make it work, just wish I knew why. I need to go through my apps and remove what I am not using, this may provide me with some results, as well as clean out my system!

What I REALLY need to do is do a clean install. One of these days! :p Maybe when I upgrade to an M5MAX if they ever get around to making that chipset!

That is exactly what A/V Output is supposed to do, turns what ever your 2nd display is into a pure, no frills, no menu bar display, and it does work when set correctly. Oddly enough, I just launched my project, and the A/V Output magically worked without issue. I guess the overnight gremlin got into my system and fixed it, that or me deleting out a super old app that I never use anymore, Smartsound Sonicfire-pro, actually fixed the issue. It's the one app I kept from the old MacPro days (2006 - 2015). I will need to test again, but I may have fixed it! Time to reboot! Fingers crossed.

But back to the point, when working, set your target display A/V Output in playback settings, then Window pulldown, select A/V Output, that should do it, unless you had my issue, which I went into great detail above on how to fix. Off to reboot land!

Canvas output, I think I knew that, and I've been working with FCP since 2006, I think that was version 6 days even! Back when the app came as a suite and you spent over 2k for the whole set! Luckily, the production I was working for footed the bill for it, and all the gear to edit in HD, which was pretty novel for the time, esp. for the Bay Area, while they had broadcast HD there (720p or 1080i yuk) the production I was on was the first to send them (KGO7) an HD formatted show delivered on, get this, a Panasonic D-5 tape that had captions added from a video lab in LA! Bonkers time, but I got to edit in HD in my basement on FCP7 using a MacPro tower and a Blackmagic HD card that had HD-SDI capabilities. Quite an operation. Yes, I had a D-5 deck and a BVW-75 Beta deck for analog in my basement, still have the BVW!