Since you trained the model I’m assuming you are able to create dataloaders for the videos you want to test it on.
The following is a rough outline of how to load your saved model and test on different datasets:
device = 'cuda'
 # create an instance of your model with required args
model = Model(**kwargs) 

 # assuming you saved your weights as torch.save(f='weights.pth', obj=model.state_dict())
saved_weights = torch.load(weights_path)
model.load_state_dict(saved_weights) 

model.to(device)
model.eval()

for video_frames, targets  in test_loader:
  video_frames, targets = video_frames.to(device), targets.to(device)
  out = model(video)
  # evaluation logic goes here