add frcrn model

examples/frcrn/step_2_train_model.py

@@ -175,7 +175,7 @@ def main():
         step_idx = int(step_idx)
         if step_idx > last_step_idx:
             last_step_idx = step_idx
-    last_epoch = 1
+    # last_epoch = 1
 
     if last_step_idx != -1:
         logger.info(f"resume from steps-{last_step_idx}.")