Question on Creating a Custom Dataset in AVA Format: Clarification on Proposal and Annotation Boxes

Hello, I would like to create my own dataset following the AVA dataset format. Are the boxes in the proposal file the same as the annotated boxes, meaning that I should first generate the boxes and then label the actions within these generated boxes? Or is it that the proposal file boxes are generated by a detection algorithm and then ignored, while I manually draw new boxes and annotate human actions? Thank you!