the perils of Perian

QI’ve been importing AVCHD video from a Sony camcorder memory card to Final Cut Pro for some time without problems.

Just recently, the video has transferred fine but its audio is missing completely. What’s wrong?

AThere have been some issues in handling AVCHD, but Apple mentions this only in relation to Photos and it should have been fixed by the update to macOS 10.13.6.

A common cause of video format trouble is incompatibility with the discontinued but popular Perian, which adds a pane to System Preferences. Perian has been used to extend QuickTime support to a rich range of different media. To get rid of that pane, ≈-click its icon and choose Remove. Also check QuickTime’s folders for obsolete components such as msmpeg4v1 – see ‘Installation and Removal of Perian’ at perian.org.

After that, force validation of audio units: in Final Cut’s preferences, click General, then (next to Audio Units) Validate on Next Launch. Quit the app, reopen it, and all audio units should be checked and validated. Play an AVCHD video to check if the issue is fixed.

Also see what happens when you disable the removal of silent channels in Final Cut’s Import preferences and reimport. If still unfixed, try converting outside Final Cut with AVCHD to Mov Lite (Free, geranium-soft.com).

When you tell Final Cut to validate Audio Units, it should report it has done so when next opened.