[ADD] better names in loss weight

Author: nviolante25

sgm/modules/diffusionmodules/loss_weighting.py

@@ -34,9 +34,9 @@ def __call__(self, sigma: torch.Tensor) -> torch.Tensor:
 class SevaWeighting(DiffusionLossWeighting):
     def __call__(self, sigma: torch.Tensor, mask, max_weight=5.0) -> torch.Tensor:
         bools = mask.to(torch.bool)
-        batch_size, num_frames = bools.shape
-        indices = torch.arange(num_frames, device=bools.device).unsqueeze(0).expand(batch_size, num_frames)
-        weights = torch.full((batch_size, num_frames), max_weight, dtype=torch.float, device=bools.device)
+        batch_size, N = bools.shape
+        indices = torch.arange(N, device=bools.device).unsqueeze(0).expand(batch_size, N)
+        weights = torch.full((batch_size, N), max_weight, dtype=torch.float, device=bools.device)
 
         for b in range(batch_size):
             true_idx = indices[b][bools[b]]