Final Cut won't play or transcode my mp4 files

Hello! I have a new 16" MacBook Pro with M3 max, Sonoma 14.7.6. I'm using Final Cut Pro 11.1 (trial version, but I doubt that's the problem).

I'm trying to import and work with a bunch of .mp4 files but they won't play on Quicktime and when I import them to FCPX they're all black. Audio works just fine, they play fine on VLC too. They're quite heavy files (about 2TB in total) but my drive is 12TB and fast enough (I've used it at work countless other times). I can't for the life of me where the problem is, I'll attach a few screenshots if that helps. I've worked with this same files on another Mac at work, they play fine and there are no issues on FCPX. I have tried creating a new library, moving some files from the drive to my desktop and nothing works. Please help, I'm at my wits' end with this.

[Edited by Moderator]

MacBook Pro (M3 Pro, 2023)

Posted on Jun 16, 2025 2:51 PM

Top-ranking reply

joema

Level 4

1,101 points

Posted on Jun 17, 2025 7:37 PM

Here is a possible way to troubleshoot this:

Take the file to the other Mac that plays them.
Verify they play in Quicktime Player on that machine.
Use the Quicktime Player's built-in feature to trim a very small piece of that clip. This does "no encode" trimming, so the extracted piece will have all the characteristics of the original long clip. If the original clip has color bars on the header or a broadcast logo, a two-second version of that is sufficient. Instructions: Trim a movie or clip in QuickTime Player on Mac - Apple Support
Take the little 2-sec clip back to your M3 Max and verify it won't play.
Upload that 2-sec clip to us for analysis. Put it on a file-sharing site we can access.

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20 replies

HSantana_ Author

Level 1

4 points

Jun 17, 2025 4:46 PM in response to terryb

Thing is each file is approximately 24GB, the entire show is in it. Thinking back on it, I don't think this was shot with Black Magic cameras, but they do use a Black Magic deck and Black Magic streaming encoder (I think) in the production room, so that’s probably what mediainfo is showing. These files are not camera originals. They are the full thing, just like how it was aired. Recorded in the production room at the same time it was airing.

They work fine in my office Mac, but in my personal Mac I can’t seem to make them work. Quicktime won’t open them, FCPX won’t transcode or analyze them. The fact that I can work with them on my office Mac makes me think that there's something missing on my Mac but I just don't know what. Should I update it to Sequoia? I already updated the video formats.

HSantana_ Author

Level 1

4 points

Jun 17, 2025 2:46 AM in response to Tom Wolsky

Yes, this is what I get from MediaInfo. All the files come from the same place so they're pretty much the same as this one

HSantana_ Author

Level 1

4 points

Jun 17, 2025 5:59 AM in response to Tom Wolsky

Here's the full report (this is my first time using MediaInfo, sorry!). I can't upload the files because they belong to the TV show I work for, so I'd get in major trouble.

HSantana_ Author

Level 1

4 points

Jun 17, 2025 3:34 PM in response to terryb

I don't know if it was shot HDR, I have no idea about the cameras or the config they use down at the studio. If there's anyway I can find that out looking at the files please let me know.

HSantana_ Author

Level 1

4 points

Jun 17, 2025 6:00 PM in response to terryb

I don't think so, at least not that I know of. I've never had to open any external software to edit besides FCPX

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Final Cut won't play or transcode my mp4 files