Bug FCPX 10.8? no more audio on .mts files!

I have told people for years to not import "bare" MTS files (ie copied outside of the AVCHD package) because it can create significant I/O performance problems. FCP was evidently trying to dynamically rewrap each clip upon each reference.

That said, importing "bare" MTS files has nonetheless worked for 10 years. MTS files are mentioned as supported on Apple's "Media Formats Supported" page: Media formats supported in Final Cut Pro for Mac - Apple Support

The MTS audio problem with 10.8 is not limited to newly-imported files. Any prior version library containing "bare" MTS files which is updated to 10.8 will stop playing audio from those files. This is regardless of whether the files were imported using "leave files in place" or "copy to library."

In many cases the files were imported years ago and the customers no longer have the original AVCHD bundle.

I tried using EditReady to rewrap MTS files before importing to FCP 10.8 and that seemed to work. That might be a solution for newly-imported material.

However for existing MTS material in libraries and projects, the solution is less clear. I tried relinking to a few rewrapped files. Some worked and some failed due to the error "The original file and new file have no

shared media range." It will take more investigative work to determine what the options are for customers in this situation.

This should probably be filed as a bug, so Apple can state whether the change is expected behavior as of 10.8 or a bug.

There is a similar format with file extension M2TS. I don't know if those are also affected.

You should not be using .mts files in FCP. If that’s being ripped out of a camera card don’t. Use the import window to import directly from the card structure so the metadata remains intact and the media is properly rewrapped. .

Tom, I'm pulling some archives shot by various older cameras and testing on older FCP versions back to 10.5.2 to try and determine this.

I'll also look at the symlinks inside some older libraries I can no longer run to see if those were pointing to MTS or M2T, or M2TS files.

I'll second Tom's advice (as usual, smart man there). Apple does officially state "MTS files from AVCHD cameras" are supported, but that is only when importing inside FCP directly from the card, as Tom said. I'd be tempted to convert them to ProRes or something in Compressor, myself. Just personal preference.

Tom I can't be certain. No m2t files I have work (at all) on 10.5.3, which is the oldest version I can run. Those are from 2013, and I can't find libraries from then with symlinks pointing to m2t files.

We never shot much .m2t, just had one (I think) Panasonic HVX-200 that shot 1440 x 1080i. We switched to FCPX and DSLRs in 2013, so we never used .m2t that much, and I can't remember if it was edited in Premiere or FCPX.

We did use Canon .mts for a few things through about 2014, and that format continued to work through 10.7.1, but we never shot any new .mts material since about 2014. So losing .mts in 10.8 is a non-issue for us; we haven't shot that in years and the archives old and rarely used.

If people are still shooting new material using "bare" .mts files, I see how that would be a problem.

Have m2t files ever worked in FCP joema?

Thanks very much joema for following up.