(e.g., a car driving through a city, people walking in a mall, or drone footage).

In many computer vision contexts, this specific naming convention (b + four digits) is used for processed sequences in tracking and segmentation benchmarks. To provide the exact paper you are looking for, could you share a bit more context? Specifically:

(e.g., Detectron2, MMCV, or a specific university project).

(e.g., a specific GitHub repo like Video-Recognition or a dataset folder).

Knowing the or the GitHub repository where the file is referenced will help me identify the exact citation you need.