For example, if the name of a video is 1.mp4, then there must exist K_1, dist_1 in intri.yml, and R_1((3, 1), rotation vector of camera), T_1(3, 1) in extri.yml. The file format is following OpenCV format.
See easymocap/mytools/camera_utils.py=>write_camera, read_camera functions.
TODO