I recorded a video in 4320 x 7680 with my phone in portrait with the intention of uploading to Tik Tok, Instagram, etc. I have my project set to exactly that, with an aspect ratio of 9:16, but whenever I go to export a MPEG-4, those settings are unavailable. I'm only able to export a normal 16:9 aspect ratio. Interestingly, my desired settings ARE available if I go to export an AVI. However, when I go to do so, I get an error message about an external codec.
I figured I would work around this by just making my video in a 16:9 ratio (with the intention of flipping it later), but when I go to export a 16:9, 7680 x 4320 MPEG-4, the final exported video is slowed down drastically and unusable.
I'm using Movie Studio 2023 Suite, Windows 11 Home, 11th gen Intel I7 11390H, 16gb Ram