[bugfix] Correct valid frame sample check in LambdaSampler

src/torchvideo/samplers.py

@@ -252,7 +252,8 @@ def __init__(self, sampler: Callable[[int], Union[slice, List[slice], List[int]]
 
     def sample(self, video_length: int) -> Union[slice, List[int], List[slice]]:
         frame_idx = self._fn(video_length)
-        if not all([i < (video_length - 1) for i in frame_idx_to_list(frame_idx)]):
+        frame_idx_list = frame_idx_to_list(frame_idx)
+        if not all([i < video_length for i in frame_idx_list]):
             raise ValueError(
                 "Invalid frame_idx {} from user provided sampler for video of "
                 "length {}".format(frame_idx, video_length)