Fix RuntimeError: Caught RuntimeError in pin memory thread for device

0."

ref #172

Author: r9y9

train.py

@@ -340,8 +340,10 @@ def collate_fn(batch):
     s, e = 1, max_decoder_target_len + 1
     # if b_pad > 0:
     #    s, e = s - 1, e - 1
+    # NOTE: needs clone to supress RuntimeError in dataloarder...
+    # ref: https://github.com/pytorch/pytorch/issues/10756
     frame_positions = torch.arange(s, e).long().unsqueeze(0).expand(
-        len(batch), max_decoder_target_len)
+        len(batch), max_decoder_target_len).clone()
 
     # done flags
     done = np.array([_pad(np.zeros(len(x[1]) // r // downsample_step - 1),