The easy workaround to get iMovive work with H.264 videos on macOS Sierra smoothly is to convert H.264 to Apple InterMediate Codec, which ensures the best result when using in iMovie.
Have you ever run into a situation where you can’t edit H.264 files in iMovie since you upgraded your Mac OS X to macOS Sierra? In this part we’ll look at how iMovie deals with H.264 video clips, and how you can import them for smooth editing. Now just check out the H.264 to iMovie on macOS Sierra workflow.
Actually, iMovie is pretty picky with the codecs of what it'll accept; it doesn't support H.264 as source files well. To solve the issue, a common practical way is to convert H.264 to iMovie most compatible video like Apple InterMediate Codec. You are recommended to use a great H.264 to iMovie Converter- Brorsoft Video Converter for Mac to help finish the task.
Overall, this Mac video converter is clean and safe to install and use. And only with barely several mouse clicks, you can get the whole job done. With it, you can fast encode H.264 files to iMovie preferred format on macOS Sierra as well as El Capitan, Yosemite, Mavericks, etc. Besides H.264, it can also transcode more video file formats like MP4, MTS, MXF, M4V, AVI, MPG, MKV to iMovie most compatible Apple InterMediate Codec .mov without any quality loss. Now just download its free trail version and follow the below guide to convert H.264 files to edit in iMovie 08/09/11 smoothly.
How to Convert H.264 and Import H.264 to iMovie
Step 1: Load H.264 files to the program
Launch the MP4 to iMovie Converter and click "Add File" button to locate the H.264 file(s) you want to add. Check the "Merge into one file" box, you can join several .mp4 clips together if necessary.
Step 2: Select the output format
Click Format bar and you can choose iMovie/FCE -- > Apple InterMediate Codec(AIC) (*.mov) as the output format. You can also click the "Settings" icon to customize the video/audio settings including the Bitrate of Video and Audio, Audio, Video Size, Sample Rate, Frame Rate, Audio Channels, etc for iMovie.
Step 3: Start H.264 to iMovie conversion
After all the necessary setting have been done, click "Convert" button to start transcoding H.264 to AIC .mov. After the conversion, click "Open" to locate the result videos.
Step 4: Imported converted H.264 into iMovie
Finally, launch iMovie. In iMovie, go to the File menu, choose Import > Movies, and then navigate to the folder that your output H.264 files are saved. Select the files and click "Import". You’re done.
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