Why some video in my camera not support

Hey there,

Apple apps such as Photos, iMovie, Safari, Keynote, and QuickTime Player work with many media formats. Some apps prefer specific formats, but most formats work in most apps without additional software. Older or specialized formats might not work as expected if your device, its operating system, or the app you're using doesn't support the format.

Install all available software updates for your iPhone . After updating, if you don't have an app that supports the older or specialized media format used by the file, search the internet or App Store for an app that does. If you know the name of the media format, include it in your search.

This may help you understand what is supported on iOS devices. --> Supported media formats in Motion - Apple Support