string concat op taken into paranthesis

app.py

@@ -199,7 +199,7 @@ def track_and_mask(vid, masked_frame, original_list, mask_list):
 
     print('Original Frame Count: ',len(original_list))
     print('Mask Frame Count: ',len(mask_list))
-    return {out_video_inpaint:dt_string+"_output.avi",
+    return {out_video_inpaint:(dt_string+"_output.avi"),
             original_frame_list: original_list,
             mask_list: mask_list}
 
@@ -209,7 +209,7 @@ def inpaint_video(original_frame_list, mask_list):
     video_inpainting(args, original_frame_list, mask_list)
     original_frame_list = []
     mask_list = []
-    return {out_video_inpaint:dt_string+"_result.mp4",
+    return {out_video_inpaint:(dt_string+"_result.mp4"),
             original_frame_list: original_frame_list,
             mask_list: mask_list}