are using Clipchamp on a Mac
are importing video files taken on an iPhone
see the message: Converting your assets for use, this might take a while,
it's likely that these videos were recorded on your iPhone (or iPad) in the HEVC format (also known as H.265) and need to get converted first before they can get used in the editor.
If HEVC videos are synced to a Mac via iCloud Photo syncing, then exporting from the Photos app on the Mac will automatically convert the videos to the H.264 format. This is the format Clipchamp works with and clips will import quickly.
However, videos will stay in HEVC format if they are transferred to your Mac by:
the Files app on iOS, then reading them from the iCloud Drive folder on your Mac.
iCloud Photo syncing but imported directly from the Media|Movies folder in the file open dialog (i.e. not exported from Photos)
In these cases, Clipchamp will convert them from HEVC to H.264 format as part of the import process, which can take some time.
To get your videos to load more quickly, export them from the Photos app on your Mac. This will automatically convert them. The steps are simple:
drag the videos into Photos.
drag them back out - you can drag them back to the same folder, and they will get a new file name.
When you drag HEVC videos out of Photos, they will be converted to H.264 automatically and quickly. The files will be slightly larger but will import into Clipchamp much faster than their HEVC counterparts.
For example, a short 1 second HEVC video can take up to 60 seconds to import into Clipchamp. However, converting it by dragging it out of the Photos app, then importing it into Clipchamp takes only two seconds.