check rgb video existence

.gitignore

@@ -201,3 +201,6 @@ __marimo__/
 
 # Streamlit
 .streamlit/secrets.toml
+
+/logs/
+/data/

app.py

@@ -287,6 +287,10 @@ def generate_video(
 
     log.info(f"actual_seed: {actual_seed}")
 
+    if not os.path.isfile(rgb_video_path):
+        log.warning(f"File {rgb_video_path} does not exist")
+        rgb_video_path = ""
+
     # add timer to calculate the generation time
     start_time = time.time()