Do you see Artefacts or Media Distortion after exporting the Video Project in Final Cut Pro X?
VIDEO ARTEFACTS
NOTE: This article is for a FCPx user. Although, similar concepts might apply to other video editing softwares, the solution below is specifically for FCPx.
What you see in the above picture is a screenshot of a video artefact taken from a video. The same video, when played in FCPx timeline, plays just fine before the export. It’s after the export when you start to see the artefacts.
You might have tried the following to resolve the issue but the issue remained.
Tried exporting the project in different codecs.
Tried exporting the project in MOV and MP4 containers.
Restarted FCPx and then exported the project.
Changed the clip/transition duration etc. but every time you exported, the glitches reappeared, although at different points.
When I ran into this issue, my environment was running FCPx 10.4.8 on Catalina 10.15. Here’s how I fixed my issue.
THIS IS HOW I FIXED THE ARTEFACT ISSUE
STEP 1:
Play the exported problematic video and make a note of the clips where the artefacts appear.
STEP 2:
In the project timeline, put the playhead on the problematic clip and press Shift-F. This will highlight the clip in the browser window. Using the SHIFT-F option, will save you from having to reimport an optimized clip to the timeline.
STEP 3:
Right click on the highlighted clip, select Transcode Media… option and then select Create optimized media. Press OK. Depending on the length and resolution of the clip, it might take some time. Once complete, you will see the Optimized dot turn green in the info part of the Inspector section.
STEP 4:
You might have to repeat STEP 2 & 3 for any clips which had artefacts after the export.
STEP 5:
Once you are done, export the project again. Hopefully, this time the video will not have any artefacts.
SO WHAT WAS CAUSING THOSE ARTEFACTS?
The problematic clips, in my case, were mostly recorded with iPhone X. The codec used for those clips was HEVC (H.265). It could be that Final Cut Pro did not like that codec. By optimizing those clips, what we essentially did was transcoded the media from HEVC to Apple ProRes 422 format. According to Apple, ProRes 422 codec provides better performance in Final Cut Pro.
Here is an article on Apple support page, which sheds some more light on HEVC media not performing as expected in FCPx 10.4. Please note that the article is not fully applicable in my case, since I was on Catalina.