How to transcode Sony Alpha a7S AVCHD for FCP X

Final Cut Pro X won't import Sony Alpha a7S AVCHD mts files after the upgradation to macOS High Sierra? Actually, this is a known issue. Before Apple releases a fix for the problem, you can solve the issue via transcoding Sony Alpha a7S AVCHD footage to Apple ProRes codec encoded QuickTime MOV format first before you start editing in FCP X.

"My FCP X no longer working with Sony Alpha a7S AVCHD mts files. Why did this happen? Just upgraded to the latest High Sierra, and can no longer access .MTS files on my desktop through Final Cut Pro X. Is there anything I can do to solve the issue? Please help."

Actually, this is a known issue between AVCHD and FCP X on High Sierra. It can be solved via transcoding Sony Alpha a7S AVCHD mts files into FCP X preferred ProRes codec. Check a how-to guide on this below.

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How to transcode Sony Alpha a7S AVCHD mts files to ProRes for FCP X?

To transcode Sony Alpha a7S AVCHD footage to ProRes for FCP X, do as below:

Video Converter (It is available for Mac, simply download the proper version depending on your computer.)

Step 1: Import Sony Alpha a7S AVCHD mts files. Start up Video Converter for Mac and click "Add File" to load Sony Alpha a7S AVCHD video files that you need to convert into this program. This converter supports batch conversion, so you can import a bundle of Sony Alpha a7S AVCHD video files into it to do conversion at a time.

Step 2: Choose output format for FCP X from "Profile" list Working well as an Sony Alpha a7S AVCHD converter app, Video Converter for Mac comes with a flavor of Apple ProRes codecs , including Apple ProRes 422, Apple ProRes 422 (HQ), Apple ProRes 422 (LT), Apple ProRes 422 (Proxy) and Apple ProRes 4444. For a good balance between quality and file size, we would recommend choosing "Apple ProRes 422 (*.mov)" as output format under "Final Cut Pro" column. The ProRes 422 codec will ensure a good performance working in FCP X even on an old Mac machine.

Tips: If necessary, you can click "Settings" button to modify video and audio parameters like encoder, resolution, frame rate, bitrate, aspect ratio, sample rate, and audio channels. You can also "Enable 3D Settings" to add 3D effect to your source media.

Step 3: Start Sony Alpha a7S AVCHD MTS to FCP X conversion. Click "Convert" to start Sony Alpha a7S AVCHD mts video to ProRes 422 conversion for FCP X. As soon as the conversion is complete, you can click "Open Folder" to get the generated Apple ProRes 422 files for editing in FCP X with optimum performance. Hope it helps.