Problems exporting aiff or wav audio files in fcp x

Hello fellow editors,

I'm mixing audio for a 3 hour long pool match and I would like to mix outside of fcp x and stp. I'm trying to export the audio as either AIFF or WAV, which both give me a 10gb file size estimate. At about 40% into the rendering process I experience:

"The share operation Export File has failed, The audio file format does not support file sizes greater than 4GB".

Has anyone else encountered this? Is there a file size limit I was unaware of for those audio formats? Any help on exporting the audio uncompressed would be very much appreciated.

I'm having the same issue. Randomly it worked once, then all of a sudden....the error is back.

Yes there is a maximum recording size according to file type, as follows:

1. The AIFF file format cannot handle audio file recordings larger than 2 GB.

2. The WAV file format cannot handle audio file recordings larger than 4 GB.

3. If the size of your recording exceeds the above limits and your audio guy or your DAW can handle this format, choose the CAF (Apple Core Audio Format) file format, which can handle the following recording times:

About 13 hours and 30 minutes at 44.1 kHz
About 6 hours at 96 kHz
About 3 hours at 192 kHz

The bit depth and channel format—mono, stereo, or surround—do not affect the maximum recording size of CAF files.

If your audio guy or your DAW cannot handle CAF you will have to split up your edit into manageable chunks which he can assemble in his DAW. Or if you have Compressor installed you can create a custom AIFF or WAV export setting using 44.1 kHz instead of 48 kHz (which is the default in FCPX). Then you can add this custom setting to your FCPX Share menu and export your timeline using the new setting.

- Ronny

Another thing to note is that FCPX usually exports audio with a 24-bit depth (at least that's always been the case in my experience). Be sure to change this to 16-bit. A 16-bit 48Khz file can easily fit 3 hours of audio in under 4 GB. Otherwise it's .CAF all the way.

You nailed it brother! Thank you soooo much.

Perfect! Thanks. CAF it is!

Just to add to the conversation a thanks for letting us know about using CAF. I also finally figured a way to extract the surround sound 5.1 mono AIFF stems from the CAF using Audacity and here are the instructions.

• After exporting each CAF, open in Audacity
• Change the first two tracks from L & R to mono using the little down triangle near the name of the track.
• [optional] Add the channel label after the name of each track (“Example 1 L”)
• Then FILE>EXPORT MULTIPLE…
• Leave the “Export Format” on “Other uncompressed files” then click “Options...” and change to the same bit (ex 24bit) as the CAF or original file's bit depth.
• Then just pick where you want to export
• Order should be 1 L, 2 R, 3 C, 4 LFE, 5 Ls, 6 Rs, but you can verify by opening the CAF in QT7 or other app that displays it

Thanks Ronny, I had totally forgotten about file size limits in AIFF/WAV.

When I saw the 4GB limit, I immediately thought of file size limit of FAT formatted drives.

Still to go over 2/4GB is a lot of audio, ear fatigue :ohmy:

Thanks, Greg