About the fps used for sampling

Why is the [fps](https://github.com/line/lighthouse/blob/main/lighthouse/frame_loaders/slowfast_loader.py#L149) of the original video (before resampling and double padding) used to calculate the number of frames for sampling intervals, instead of the target_fps after resampling and double padding?I think there is a discrepancy here.

Read lighthouse/frame_loaders/slowfast_loader.py around line 149 and trace how the original fps and target_fps are used after resampling and double padding. Compare the frame-count calculation with the sampling intervals and determine whether the discrepancy is real; the issue is done when the behavior is corrected or clearly explained with coverage for the chosen calculation.

Written by the indexing model from the issue text.