Importing and editing AVCHD MTS video files

[Jeff Kirkland]

As your shooter said, FCPX will happily work with the MTS footage and will rewrap the files in the background if it needs to – but if you want a little more control over the process, I’d suggest manually converting the media before import using an application like EditReady.

I tend to use EditReady most times so that I have control over file renaming, folder structure, etc.

—-
Jeff Kirkland | Video Producer & Cinematographer
Hobart, Tasmania | Twitter: @jeffkirkland

[Joe Marler]

Under no conditions import bare AVCHD MTS files using “leave files in place”. They should be either (1) Imported from the AVCHD bundle and allow FCPX to copy to the library or (2) Re-wrapped externally with EditReady then imported using “leave files in place”.

When the files are re-wrapped by either FCPX or EditReady they are not transcoded to ProRes. They are still H264 but for some reason the container format allows FCPX to work more efficiently.

Using Finder to copy bare AVCHD files out of the package and importing with “leave files in place” can create an anomalous I/O-intensive condition which greatly degrades library performance, even if only a small % of those files are in a library containing mostly other media types. Examination with Dtrace shows the I/O profile seems to consist many small random I/Os. It may be dynamically re-wrapping each MTS file upon each reference. This behavior is more apparent if the Event Browser is in filmstrip mode and manifests as very sluggish and continuous thumbnail generation. Using the above methods avoids this. In theory if the bare MTS files are already imported you can probably create optimized media as a workaround.

AVCHD is HD resolution not 4k, so if it is imported properly as described above, performance should be OK.

Normally optimized media isn’t required for HD resolution H264. However your 2010 Mac Pro uses Xeon CPUs which does not support Quick Sync, so there is no hardware acceleration for H264 encode/decode.

Due to the lack of Quick Sync, for heavy multicam work it’s conceivable you might need optimized media even for HD resolution. You can evaluate this by importing as described above, making a test multicam and checking edit performance. If it performs OK you don’t need it.

[Jeff Kirkland]

[Joe Marler] “When the files are re-wrapped by either FCPX or EditReady they are not transcoded to ProRes. “
EditReady will convert them to ProRes if you tell it to. I tend to convert to ProRes but that’s mostly because I’m using a 2013 Mac Pro which doesn’t handle h264/h265 all that well.

—-
Jeff Kirkland | Video Producer & Cinematographer
Hobart, Tasmania | Twitter: @jeffkirkland

[Joe Marler]

[Jeff Kirkland] “EditReady will convert them to ProRes if you tell it to. I tend to convert to ProRes but that’s mostly because I’m using a 2013 Mac Pro which doesn’t handle h264/h265 all that well.”

Good point; I only meant the default EditReady conversion for this case is rewrap, not transcode. If rewrapping is acceptable from a performance standpoint, it is much faster than transcoding, plus this enables import with “leave files in place”.

The big question is how will the 2010 Mac Pro handle re-wrapped AVCHD for multicam? I formerly had a 12-core D700 Mac Pro, so I know it nor older Mac Pros handle 4k H264 very well. But maybe AVCHD’s 1080 resolution (which is 1/4 the pixels) would be acceptable. The OP will have to test this.

[Dave Gage]

[Joe Marler] “Under no conditions import bare AVCHD MTS files using “leave files in place”. They should be either (1) Imported from the AVCHD bundle and allow FCPX to copy to the library or (2) Re-wrapped externally with EditReady then imported using “leave files in place”.”

Joe,

Pretty cool, I came here specifically for this topic not knowing there would be a recent thread about it. I haven’t visited or posted here in many years.

I started many years back with FCP X 10.04 on OS 10.6.8 (2011 17″ MBP) and did a ton of editing for my websites and Youtube, but haven’t had any pressing editing needs the last 4 years or so. When I went to Sierra, I also upgraded FCP X to 10.4.

The last couple of weeks I started editing some live music video footage shot in 1080p 29.97 and .mts format. It was really, really, really slow. I figured since the OS and QuickTime Player understood the .mts format now that FCP X must understand the format by default too. I was wrong.

I muddled through an edit or two and tried using a proxy file which certainly did help, but something still seemed wrong. My immediate reaction was that Apple must be trying to force me to buy new hardware (which won’t be happening anytime soon-still have two of the 2011 MBPs). After more thought, I figured I’d try my old ClipWrap app for a quick re-wrap test which was a must do back when I was editing a lot. It worked great!

So, you’ve confirmed what I discovered and I also found out that my old ClipWrap became EditReady2. I don’t see any pressing reasons to upgrade my ClipWrap (for $30), so I guess I’m good to go. Thanks to all and it’s nice to see that Jeff is still around.