I tried for days to get a movie imported into Cubase 10, using all kind of conversions, but could not get it to work.Just for the fun of it (or desperation…) I tried it in Cubase 8.5 and it imports without a problem. Why is this? Even next to having removed the export video with music in version 10, it also has limitations on importing video formats?
Cubase 10 is using different video engine than Cubase 8.5. Here you can find useful “Video support in Nuendo, Cubase and Dorico” article.
Here is a FFMPEG command-line script to convert any video for Cubase so it works as fast as Sonic the Hedgehog.
ffmpeg -i "YOUR_VIDEO.mp4" -c:v mjpeg -an -vf scale=720:-1 OUTPUT.mov