Odd frames added to start of audio export from LPX when imported into FCPX

Question

Running into a weird issue exporting audio out of Logic Pro (10.0.6) for import into FCPX (10.1.1) - Logic is introducing extra frames (varies between 2 to 4 frames) at the front of exported audio, becomes detectable when imported back into FCPX.
I do a lot of work where I sync music performances on camera that are recorded in audio and MIDI, and have to deliver remixed audio with picture AND a .MID file that all sync. Workflow used to be shoot video on a C100 and another DSLR with either an audio feed or live mic patched to the camera, while Logic recorded the MIDI performance and any ambient audio via separate mics and pres. Shoot always had some kind of "slated" start marker on camera, in camera audio, and in Logic. Camera edits were edited in FCPX, exported as a Quicktime with the "slate" for a start marker, then audio and MIDI handled in Logic.
This always used to work thru to last fall, when we took a hiatus.
Upon resuming some final shooting in the last two weeks, our audio edits are always running 2-4 frames behind FCPX. It's a consistent offset for an entire export (so there's no drift, no jitter within the files - but the slate tones might be 2 frames and 17 subframes behind and the whole audio file runs behind.) Another export might be 3 frames 2 subframes behind. Always kind of random in the amount of drift - but never more than 4 frames.
Tried a test where I imported just the camera audio in Logic as an extracted audio track, then exported same audio file back to the Quicktime but left the original audio in the video - Logic's exported audio ran behind sync from the original.
Obviously, I'm paying attention to frame rates, sample rates, etc.
As a test, I exported an XML out of FCPX, imported it into Logic, performed some edits, and used the File>Export>Project to FinalCut Pro XML - so everything matched across the board. Opened the export in FCPX - audio ran behind sync again.
If it was just audio I was concerned about, I'd just line it up in FCPX and call it done - but my exported MIDI file NEEDS to be in sync with the picture AND the audio... and wasting time calculating the Logic offset error is a huge detour from getting this work done quickly.
I thought maybe there could be a plug-in issue, but it happened even in the extracted audio from the Quicktime with no plug-ins in any of the signal chains.
Any ideas?

Answer 1

Well… here's a clunky workaround.
It's either a problem with the exported FCPX-XML or the way Logic Pro X interprets the XML.
The simple test here was to put a clip in the FCPX timeline and export it as an AIFF and then export an XML too.
Import the XML into Logic, then import the AIFF as a new track. By default the Logic project is 120BPM. By analyzing the xml-based track and the aiff track, the xml track has an added 164 ticks to the beginning of the referenced video-audio.
Move the playhead to zero, zoom in to the timeline and drag the tick field to 164 then blade all your tracks, then click/drag the bladed tracks to zero. Voila!
It seems to only affect the first audio file. So for example, when I have 10 video clips in my FCPX timeline, only the first audio clip has the added 164 ticks.
Now on to the next challenge…
It's not enough to just de-compound your clips because L and J cuts get referenced to the VIDEO, not the audio underneath.
So… In FCPX you MUST select each clip and choose Break Apart Clip Items from the Clip Menu. Perhaps this is old news but thought I'd mention it here in case others were having problems.
Let's hope Apple steps up their xml game and realizes that when I choose export XML-Audio from the xml popup menu… I want it to send the duration of the audio, not the duration of the attached video.
Ergh! Well… as my friends say… "We're still in the stone age with all this technology."
Happy editing all!