There is no mirror effect setting in the video clip that comes with OPPO mobile phone. You need to download an additional application to view the application you want to upload. Any APP that records video can set up mirroring.

OPPO image mirroring inversion: first, open the photo album application in the mobile phone, select the image to be mirrored, then select the following editing function to edit the image, find the cropping rotation function to crop and rotate the image, and select the mirroring function to mirror the image.