Confused with coordinate of 3D box

[kaiopen]

The function boxed_cam_to_velo in file "utils.py" projects the position of ground truth 3D bounding box to velo coordinate just with calibration matrix Tr_velo_to_cam. Does that mean the position is in camera 0 coordinate rather than rectified camera 0 coordinate? I have read some codes, such pointnet and frustum pointnets, which consider the position in rectified camera 0 coordinate.