The .mts (or .m2ts) files shot by Sony, Canon, JVC or Panasonic AVCHD cameras are highly compressed by H.264 codec and they are very hard to deal with during video editing. That's why users usually run into incompatibility issue when using MTS files in Final Cut Pro or can't edit them smoothly after taking some time for importing MTS to FCP 7/X, let alone the non-standard formats of 1080p50 and 1080p60 which FCP does not work with. Since ProRes is a lossy video compression format that developed by Apple and it's a appropriate format for smooth editing in Mac, the easy workaround is to convert MTS/M2TS to ProRes for FCP.
We all know FCP 7 itself offers an optional way to let you log and transfer some of the AVCHD mts files to ProRes, however, it's a bit slow and not reliable (e.g. the program may crash about 2/3 or 1/3 into the transfer process). So you'd better get a third-party program for help. To transcode piecemeal MTS clips to ProRes quickly and easily, EaseFab Video Converter for Mac OS X (macOS Mojave compatible) is highly recommended. This program features high efficiency and seamless conversion. With it, you can do batch conversion from AVCHD, MTS, M2TS, M2T, AVI, VOB, MP4, XAVC, XAC S, MOV and more to ProRes in simple clicks of mouse. And the output video ensure maximum editing quality and efficiency when working with Final Cut Pro. Here's how to do it.
Free download MTS to ProRes Converter trial version:
How to Convert MTS/M2TS to ProRes on Mac OS X(macOS Mojave)
Step 1. Add MTS/M2TS files
Drag and drop your MTS/M2TS files from where you stored to the program. Several files can be selected and processed at the same time to save up time. Batch conversion is supported so you can add multiple files to convert at a time.
Step 2. Choose ProRes as the output video format
Now click the Profile icon to reveal output panel. And and mouse cursor to "Editing Software" category. You'll find several ProRes formats are provided. Generally, ProRes or ProRes LT are suitable choices for MTS, M2TS, DV videos shot with camcorders. ProRes HQ is usually for film based source media. To edit your MTS videos in Final Cut Pro, you can also directly select Final Cut Pro as the output format to get videos with optimized settings to fit the video editing app.
Tip: Click the "Settings" button and customize proper video/audio parameters if necessary. Video size, bitrate and fame rate are flexible and can be adjusted as you like. Usually 1920*1080 video size and 30fps video frame rate are recommended for FCP editing.
Step 3. Start converting MTS/M2TS to ProRes
At this point, you can change the output filename or output path if you wish. If you feel satisfied with your options, Just hit the Convert button to activate MTS file to ProRes conversion.
When all conversions completed, you'll get a pop-up notice. Just click "Open" button, you can fast find where your converted files are saved.