[Rike Rodegro]

I had a similarly freaky sound problem in FCP the other day. It involved sound drifting out of sync and waveforms not matching actual sound.

Although the symptom description doesn’t cover the waveform poblem this helped:

https://support.apple.com/kb/TS1256

Symptoms
Imported audio-only files in a sequence with PAL video may drift out of sync in some cases.

Products Affected
Final Cut Pro
Resolution
If this occurs, try the following steps to resolve the issue:

Delete the audio file(s) from your sequence in the Timeline and also from the Browser.
Choose Final Cut Pro > Easy Setup.
Choose PAL from the Format pop-up menu.
Choose a frame rate (usually 25.00 fps) from the Rate pop-up menu, and a media format that matches your source video from the Use pop-up menu.
Click Setup.
Choose File > Save Project.
Choose Final Cut Pro > Quit Final Cut Pro.
Open Final Cut Pro and your project again, and re-import the audio file(s).
Edit the audio back into the Timeline.
The audio should now stay in tight sync respective to the video in the Timeline.

Additional Information
This issue can arise if you import audio files while the default sequence setting is an NTSC-related frame rate (such as 29.97, 59.94 and 23.98). Setting the preset to a PAL rate and restarting Final Cut Pro should allow newly-imported audio files to conform to PAL timing.

[Rike Rodegro]

I have a similar issue with audio (aif) slowly moving out of sync over time even though the waveforms match. In addition to that the length of the audio-clip differs from what it should be by about 4 frames. (This happens with aif generated by quicktime and by final cut, too.)

I found, that when I change the playback speed of the audio-clip to 99,9 % it has the correct length and stays in sync till the end.

This works so far, but obviously it isn’t very elegant. Any real solutions and/ or explanations greatly appriciated 🙂