I've been trying to isolate this problem for a while. I finally reported it to Pro Apps today.
Description: under specific conditions there is a reproducible FCPX data management bug when copying MP3 audio clips (or projects containing those clips) to another library. The resulting blank clip shows no waveform and is silent during playback, however right-clicking and selecting "Reveal in Finder" shows the correct playable file on disk.
(1) The source library must use externally managed media.
(2) MP3 files must be imported via drag/drop from Finder. Import via FCPX dialog does not cause problem.
(3) Destination library can use either internal or external media
(4) If "Copy optimized media" dialog checkbox is selected when drag/dropping MP3 files within FCPX to a new library, problem does not happen.
- Behavior is reproducible but somewhat erratic. In repeated testing using the same files, varying MP3 clips are blank.
- Afterward there is no way to fix the blank clips in the destination library. Relinking does not work, consolidating media doesn't work. Deleting the blank clip and copying again using "Copy optimized media" does not work. Deleting clip from source & destination libraries, re-importing to source and re-copying to destination library does not work. Once clip is blank in the destination library, that filename cannot be used.There is apparently persistent damage in the destination library.
- Problem does not happen when copying WAV files between libraries.
- In limited testing I haven't seen it with AAC/ M4A files. Note: even though AAC is compressed, FCPX does *not* auto-generate optimized MOV audio files during import like it does for MP3.
- Note: even though selecting "copy optimized media" seems to prevent the problem, there is no user-created optimized media. FCPX invisibly auto-creates optimized audio MOV for MP3 files (not WAV or AAC). This is not user-configurable.
- For the in-library case, these MOV audio files are stored in \Event Name\Transcoded Media\High Quality Media. For the external media case, the symlinks within the library point to the transcoded MOV audio files, which are stored in the user-designated media folder in \Final Cut Optimized Media\Dated folder\filenames.
- The number of blank clips may vary, even if the same test case with the same files is re-run repeatedly. Deleting the blank clips in the destination library and trying to copy those again will only recreate blank clips -- even IF the "copy optimized media" checkbox is selected on subsequent attempts.
(1) Ensure FCPX import properties are set to "leave files in place".
(2) Within FCPX, create a new library
(3) In Inspector, click Modify Settings and change Media storage location to a new folder you create.
(4) Import via drag/drop from Finder several MP3 files of any bitrate or channel configuration, using "leave files in place".
(5) Create a new library to be the destination for the file copy. This library storage can either be internal or external -- it does not matter. Note: it does not default to internal. The default will be whatever the previous library was created as.
(6) Within the FCPX Event Browser, drag/drop several MP3 clips from the original library to the new destination library.
(7) A dialog box will ask whether to include proxy or optimized media in the copy. To see the problem, make sure the "optimized" checkbox is cleared.
- Not specific to certain types of MP3 files. It happens with all file sizes, bit rates, mono, stereo, and whether encoded via iTunes, LAME, etc.
- Only known workaround once problem happens: original MP3 files on disk must be duplicated and renamed using Finder, re-import those (using different filenames) to the source library, then copy within FCPX to the destination library using "copy optimized media". The original filenames must be orphaned in the destination library and replaced one-by-one in any affected projects with the same files using different names.
- FCPX version history of this problem is unknown. I think I've seen it on prior versions.
- Not observed with AAC (M4A) audio files.
- Version and config: macOS 10.13.6, FCPX 10.4.3
- Machines: 2017 iMac Pro, 10-core, 64GB RAM, Vega 64 GPU, 2TB SSD; 2017 iMac i7-7700K, 32GB, 2TB SSD, Radeon Pro 580. Scenarios tested using media on both internal SSD and external Thunderbolt arrays.
Deleting the blank clip and copying again using "Copy optimized media" does not work.
I bet deleting the blank clip, quitting FCPX, emptying the trash, reopening FCPX and then using "Copy optimized media" would work.
FCPX is not a smart app. If you delete something and then import something with the same exact filename it will assume it's the same thing, even if it's completely different. I've often deleted Camera_001.MOV (or whatever) from the project and imported a new Camera_001.MOV from my flash drive and it assumes it's the old footage, even though the resolution, length, framerate, etc may all be completely different. It doesn't actually look at the file if it recognizes the file name. Why it does this I do not know. But it does. Gotta quit FCPX, delete, reopen, and try again.
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FCPX bug: MP3 clips are blank after copying to new library
11 Aug 2018 18:44 #96784
I bet deleting the blank clip, quitting FCPX, emptying the trash, reopening FCPX and then using "Copy optimized media" would work....
Unfortunately this does not work, at least not consistently. It's almost like it has damaged the "name space" within the destination library and no MP3 file with that name can ever be used again.
If you remember to always copy MP3s to other libraries using "copy optimized media", then it doesn't happen. However it's not logical that users would perceive MP3 files would have automatically-generated optimized media in the form of MOV audio files. Hence they would not think to use "copy optimized media" when only copying MP3 files to another library.
It's also not always practical to use the "copy optimized media" checkbox. When making a transfer library or smaller archive library, you are copying lots of audio and video files, and it's not even apparent within FCPX whether it's a WAV or MP3. You often don't want to copy optimized or proxy media, so people will tend to not check "optimized". If copying MP3 files to another library this can cause the problem, assuming the other conditions are met.
How the MP3 file was originally imported is also a factor. If it was imported using the FCPX dialog, it doesn't happen. If it was imported using drag/drop from Finder, it can happen. Yet there is no way to inspect how previous MP3 files were imported.
Once an MP3 file is copied to another library under the previously-listed conditions, and if the "blank clip" problem happens, it appears that filename can never be used again in that library. It seems quite serious.