diff --git a/pc.py b/pc.py
index 3ae1265..71f9e47 100644
--- a/pc.py
+++ b/pc.py
@@ -70,7 +70,7 @@ def read_images():
     def save_data():
         np.save(data_fn, data)
     src_fn = f'{src_dn}/{stop:08d}.jpg'
-    if not os.path.exists(src_fn):
+    if not os.path.exists(src_dn):
         os.makedirs(src_dn, exist_ok=True)
         os.system(f'ffmpeg -i "{video_fn}" -q:v 1 "{src_dn}/%08d.jpg"')
     cell_dn = f'{src_dn}_{cell_w}x{cell_h}'