Rat 7M Videos Subject 2 - Day 2

All videos for Subject 2, Day 2 in Rat 7M. The video naming scheme is s{subject_id}-d{recording_day}-camera{camera_id}-{starting_frame_idx}.mp4. Subject ID, recording day, and camera ID match videos to the data in the motion capture and camera calibration parameter .mat files. Videos are provided in 3500 frame chunks, with the index of the starting frame in each file denoted by the {starting_frame_idx} portion of the filename. Using the 'frames' field in the 'cameras' struct inside 'mocap.mat', the corresponding video file and frame index can be calculated by used frame_idx // 3500 to get the {starting_frame_idx} and frame_idx % 3500 to get the frame in that file.本数据集包含大鼠7M（Rat 7M）中第2号受试对象第2天的全部视频。视频命名规则为`s{subject_id}-d{recording_day}-camera{camera_id}-{starting_frame_idx}.mp4`，其中受试对象编号、录制天数与摄像机编号可用于将视频与动作捕捉（motion capture）及相机标定参数.mat文件中的数据进行关联匹配。 视频以3500帧为单位进行分块存储，文件名中的`{starting_frame_idx}`字段即标注了每个分块文件的起始帧索引。通过读取`mocap.mat`文件中`cameras`结构体的`frames`字段，可利用目标帧索引`frame_idx`：将其整除3500即可得到分块文件的起始帧索引`{starting_frame_idx}`，将其对3500取模即可得到该分块文件内的具体帧位置，进而匹配到对应的视频文件与帧序号。