exception for only "cam1.csv" available

coordinate_g.py

     d2['x'] = 1920 - d2['x']
 
     df_conc = pd.concat([d1,d2])
+else:
+    df_conc = d1
 if len(d1) == 0 and len(d2) == 0:
     dummy_dic = {'x':[0,1920], 'y':[1080,0], 'z':[1.0,5.0], 'frame':[1,1900]}
     df_conc = pd.DataFrame(dummy_dic)